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Molecular phylogenetics and morphological evolution of St. John’s Wort (Hypericum; Hypericaceae)
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August 2012
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August 2012
... Previous studies have demonstrated the utility of the ITS region for phylogenetic inference at the species level in Hypericum [23][24][25]. The possibility of amplifying ITS-1 and ITS-2 separately using internal primers allowed Nürk et al. [26] to distinguish poorly preserved plant tissue from older herbarium specimens. In addition, inter-simple sequence repeat (ISSR) markers were successfully used to reveal the genetic diversity among and within populations of H. perforatum. ...
... In addition, to assess the relationship between the individuals, alignment of the ITS sequences was first conducted using Clustal W application in Bioedit v7.2.5 [40] with manual adjustments. Furthermore, a total of 220 ITS sequences were used to conduct a phylogenetic analysis included our six ITS sequences from Tunisia and 214 ITS sequences retrieved from the nucleotide database of NCBI [26,[41][42][43]. The phylogenetic relationship between the ITS sequences was inferred on unweighted pair group method with arithmetic mean (UPGMA) tree, based on Nei's [44] genetic distance using MEGA X software [45]. ...
... H. triquetrifolium is an ecologically and economically important plant species, with an increasing interest as an alternative source of hypericin and pseudohypericin, secondary metabolites known for their antidepressant, antiviral, antibacterial and antitumor properties [18,19]. However, limited studies are currently available on H. triquetrifolium genetic diversity and phylogenetic relationship between individuals and populations [25,26,36,59,60]. Additionally, African Hypericum species are still poorly represented in worldwide phylogenetic studies [36]. ...
Hypericum triquetrifolium Turra is an ecologically, medicinally and economically important species in Tunisia. Thirty-six Hypericum individuals sampled from 6 northern Tunisian locations were investigated for their diversity and relationships using 10 inter-simple sequence repeats (ISSR) markers and 10 morphological features at vegetative stage. The phylogenetic analysis, using 308 bp of sequenced ITS1 region, identified the Hypericum individuals as H. triquetrifolium that clustered with members of genus Hypericum section 9, 9a, 9b and 27, in agreement with the previous molecular classification of the genus. Among the 10 ISSR markers tested, 7 were scorable and yielded 91 loci with 94.5% of polymorphism. UBC848 and UBC836 were the most polymorphic ISSR markers. The level of genetic diversity (HT = 0.247) and gene flow between the six populations (Nm = 1.169) were moderate. The structure analysis revealed three genetic subpopulations: individuals of Le Krib location formed a subpopulation divergent from two other subpopulations, probably due to its northwestern and high-altitude geographic barriers, and its sub-humid microclimate. Zaghouan, northeastern location in the lower semi-arid, with the highest genetic (I = 0.370) and morphological (I = 0.631) Shannon’s information indices and, regrouping two out of the three genetic subpopulations, is the most probable zone of origin for H. triquetrifolium. In addition, morphological data showed higher diversity than ISSR data; however, no evidence of correlation between genetic and morphologic traits could be suggested in this study. These results on the genetic diversity and phylogenetic analysis will contribute to the conservation of the gene pool of H. triquetrifolium in Tunisia.
... Our taxon sampling scheme covered all available sequences of members of H. sect. Campylosporus together with representatives from the major lineages of the genus Hypericum as recognized in recent molecular phylogenetic studies (Meseguer et al., 2013;Nurk et al., 2013). Two calibration points were used for Hypericum dogonbadanicum. ...
... The phylogenetic reconstructions by Beast analysis and based on limited sampling in the present study, are to a large extent, congruent with previous comprehensive phylogenetic studies on Hypericum (Meseguer et al., 2013;Nurk et al., 2013), Clinopodium (Bräuchler et al., 2010;Bordbar and Mirtadzadini, 2019), and the tribe Astereae (Brouillet et al., 2009;Farhani et al., 2018) and are therefore reliable. Molecular clock calculations indicated different divergence times for the three species. ...
The Zagros Mountain range in western Iran is an area of species endemism within the Irano-Anatolian biodiversity hotspot. A couple of relict and morphologically isolated species have been reported for the Zagros Mountains, yet their distribution patterns in relation to the geological and climatic history of the region are not fully understood. Clinopodium kallaricum (Jamzad) Bordbar, 2019 (Lamiaceae), Hypericum dogonbadanicum Assadi, 1984 (Hypericaceae), and Iranoaster bachtiaricus (Mozaff.) Kaz. Osaloo, Farhani & Mozaff. 2018 (Asteraceae) are local endemic species restricted to Zagros with no clear affinities to the Irano-Turanian or other Northern Hemisphere temperate species. Previous studies suggested some afromontane relations for these species, beyond the Saharo-Sindian lowlands. Here, we provide dated phylogenies for these three species, to assess the most probable drivers behind this pattern of distribution. Our results represent that the split between these taxa and their relatives is not contemporaneous, implying different biogeographical histories. I. bachtiaricus originated in the Middle Miocene, while C. kallaricum and H. dogonbadanicum are relatively younger (late Miocene early Pliocene). The divergence of these taxa coincided with the major geological and climatic events of the Miocene, mainly the collision of the Afro-Arabia and Eurasia plates in 18-16 Mya and the aridification of the Sahara (started in 11-7 Mya), followed by a shift in the vegetation of the Sahara from subtropical/steppe to arid desert. The possible relict nature of these species is discussed, and the role of the Saharo-Sindian Region as a vicariant agent is highlighted, which could have subdivided formerly uniform populations and subsequently accelerated the allopatric speciation.
... 230 spp.) and Andean South America (ca. 130 spp.) are the major diversity centers (Meseguer et al., 2013;Nürk et al., 2013). A lot of species has been used as traditional medicine in the world, such as H. perforatum L. (st. ...
... Hypericum is a taxonomically difficult group and species relationships were not well resolved in all previous studies (Pilepić et al., 2010;Meseguer et al., 2013;Nürk et al., 2013). In total, only five DNA markers (psbA-trnH, trnL-trnF, trnS-trnG, rbcL, and internal transcribed spacer) were used in these studies and not generated phylogenetic trees with high resolution, the part reason is due to lacking of variability within these DNA markers. ...
i>Hypericum L. (Hypericaceae) is one of the best-selling herbal medicines in the world comprising ca. 500 species of herbs, shrubs, and small trees. Hypericum petiolulatum Hook. f. & Thomson ex Dyer is widely distributed in China, Vietnam, Myanmar, Nepal, India, Malaysia, and Bhutan and is used as a traditional herb to treat hemoptysis and inflammation. In this study, we sequenced and assembled the complete chloroplast (cp) genome of H. petiolulatum . The complete plastome of H. petiolulatum was 136,105 bp in length, with a large single copy region (LSC) of 93,709 bp, a small single copy region (SSC) of 11088 bp and two identical inverted repeats (IRs) of 15,654 bp. The overall GC content of the plastome was 37.0%, while GC contents of the LSC, SSC, and each IR were 35.5%, 31.0%, and 43.8%, respectively. In addition, 116 genes consisting of 76 protein-coding genes, six ribosomal RNA genes, and 34 transfer RNA genes were identified. A phylogenetic analysis of 14 taxa inferred based on cp genome sequences revealed a close relationship between H. petiolulatum and H. perforatum . The complete cp genome sequence of H. petiolulatum reported in this paper will facilitate population and phylogenomics studies of this medicinal plant group.
... Until now, most research on H. perforatum has focused mainly on the prope constituent compounds; the genetic background and resources remain scarce. systematical location of this species was revealed by a full Bayesian approach internal transcribed spacer and three chloroplast DNA sequence regions [4]. K [2] used several chloroplast markers and amplified fragment length polymo present the phylogeographic scenario for the origin of H. perforatum; they also the impact of interspecific gene flow. ...
... Until now, most research on H. perforatum has focused mainly on the properties of its constituent compounds; the genetic background and resources remain scarce. The basic systematical location of this species was revealed by a full Bayesian approach using the internal transcribed spacer and three chloroplast DNA sequence regions [4]. Koch et al. [2] used several chloroplast markers and amplified fragment length polymorphism to present the phylogeographic scenario for the origin of H. perforatum; they also discussed the impact of interspecific gene flow. ...
Hypericum perforatum (St. John’s Wort) is a medicinal plant from the Hypericaceae family. Here, we sequenced the whole chloroplast genome of H. perforatum and compared the genome variation among five Hypericum species to discover dynamic changes and elucidate the mechanisms that lead to genome rearrangements in the Hypericum chloroplast genomes. The H. perforatum chloroplast genome is 139,725 bp, exhibiting a circular quadripartite structure with two copies of inverted repeats (IRs) separating a large single-copy region and a small single-copy region. The H. perforatum chloroplast genome encodes 106 unique genes, including 73 protein-coding genes, 29 tRNAs, and 4 rRNAs. Hypericum chloroplast genomes exhibit genome rearrangement and significant variations among species. The genome size variation among the five Hypericum species was remarkably associated with the expansion or contraction of IR regions and gene losses. Three genes—trnK-UUU, infA, and rps16—were lost, and three genes—rps7, rpl23, and rpl32—were pseudogenized in Hypericum. All the Hypericum chloroplast genomes lost the two introns in clpP, the intron in rps12, and the second intron in ycf3. Hypericum chloroplast genomes contain many long repeat sequences, suggesting a role in facilitating rearrangements. Most genes, according to molecular evolution assessments, are under purifying selection.
... It has been variously placed in Subfamily Hypericoideae of a broadly defined Clusiaceae, but recently it has been assigned to a more narrowly defined Hypericaceae that consists of three tribes (Hypericeae, Vismieae, and Cratoxyleae). Collectively, as many as 9-10 but as few as five genera have been attributed to the Hypericaceae based on morphological and molecular data (Stevens 2007;Nürk et al. 2012). A recent appraisal of generic limits in the Hypericaceae using molecular data recognizes a single broadly defined Hypericum L. in the tribe Hypericeae (Ruhfel et al. 2011) together with Harungana Lam., Vismia Vand., and Psorospermum Spach in the Vismieae (Ranarivelo 2017), and Cratoxylum Blume and Eliea in the Cratoxyleae (Stevens 2007). ...
... Chromosome number diversity and evolution of Hypericaceae received considerable early attention (Robson & Adams 1968) focused primarily on Hypericum, the largest genus in the family with ca. 470-500 species (Christenhusz et al. 2017;Nürk et al. 2012). We here add the first chromosome number report for Eliea and summarize the little that is known about chromosome numbers for the Cratoxlyeae and Vismieae in the context of chromosome number data for the Hypericaceae generally. ...
A meiotic chromosome number of n=9 is reported for Eliea articulata, a monospecific genus of Hypericaceae endemic to Madagascar. This first report for the genus is a new number for the small tribe Cratoxlyeae which includes only one other genus, Cratoxylum. A hypothetical scenario for the origin of n=9 is provided in the context of known chromosome numbers for Cratoxylum and the two other tribes in the Hypericaceae. Given that x=12 has been proposed as the basic chromosome number for the family with numbers of n=11 and n=10 also reported for related species and genera, n=9 appears to have arisen as a descending dysploid from these higher numbers. Field photos of Eliea articulata are provided along with a distribution map and camera lucida drawings of meiotic chromosome figures.
... The distribution of hypericins, as a key infrageneric chemomarker, is restricted to the representatives of the sections of the clade core Hypericum (Nürk et al., 2013;Kitanov, 2001;Crockett and Robson, 2011). In contrast, phloroglucinols are synthesized in over half of representatives of the Hypericum sections (Bridi et al., 2018). ...
... The nuclear ribosomal internal transcribed spacer (ITS) region is the major DNA barcode developed for plant identification (Cheng et al., 2016). Within the genus Hypericum, rDNA ITS sequences have been widely applied for the correct identification of plants, authentication of commercial plant preparations, and investigation of phylogenetic relationships (Crockett et al., 2004;Park and Kim, 2004;Pilepić et al., 2011;Nürk et al., 2013). Among the plant DNA barcode loci, the ITS, including the mini-barcode regions such as ITS1 and ITS2 applied alone or in combination with the plastid sequences (e.g., matK, rbcL, psbA-trnH, and trnL-trnF, among others), have been used for the correct discrimination between Hypericum species (Howard et al., 2009;Košuth et al., 2010;Koch et al., 2013;Meseguer et al., 2013). ...
In the present study, we performed phytochemical profiling of several under-exploited Hypericum representatives taxonomically belonging to the sections Ascyreia, Androsaemum, Inodora, Hypericum, Coridium, Myriandra, and Adenosepalum. The authenticity of the starting plant material was confirmed using the nuclear ribosomal internal transcribed spacer as a molecular marker, DNA content and chromosome number. Phenolic constituents were analyzed using high-performance liquid chromatography to complement species-specific metabolic profiles. In several Hypericum representatives, the pharmacologically important compounds, including naphthodianthrones; phloroglucinol derivatives; chlorogenic acid; and some classes of flavonoids, particularly the flavonols rutin and hyperoside, flavanol catechin, and flavanones naringenin and naringin, were reported for the first time. Comparative multivariate analysis of chemometric data for seedlings cultured in vitro and acclimated to the outdoor conditions revealed a strong genetically predetermined interspecific variability in phenolic compound content. In addition to hypericins, which are the most abundant chemomarkers for the genus Hypericum, rarely employed phenolic metabolites, including phloroglucinol derivatives, chlorogenic acid, catechin, naringenin, naringin, and kaempferol-3-O-glucoside, were shown to be useful for discriminating between closely related species. Given the increasing interest in natural products of the genus Hypericum, knowledge of the spectrum of phenolic compounds in shoot cultures is a prerequisite for future biotechnological applications. In addition, phytochemical profiling should be considered as an additional part of the integrated plant authentication system, which predominantly relies upon genetic markers.
... Hypericum plants of the family Hypericaceae, consisting of over 500 perennial herbs or shrubs subdivided into 30 sections, are mainly distributed in temperate area [1]. Some of Hypericum plants have been used as traditional remedies in various parts of the world. ...
... The whole plants of H. ascyron collected in Tokushima prefecture, Japan were separated into the aerial parts and roots. Their chemical constituents were separately investigated by chromatographic techniques to isolate some PAPs (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). Their structures were established based on spectroscopic analyses. ...
Plants belonging to the genus Hypericum (Hypericaceae) are recognized as an abundant source of natural products with interesting chemical structures and intriguing biological activities. In the course of our continuing study on constituents of Hypericum plants, aiming at searching natural product-based lead compounds for therapeutic agents, we have isolated more than 100 new characteristic metabolites classified as prenylated acylphloroglucinols, meroterpenes, ketides, dibenzo-1,4-dioxane derivatives, and xanthones including prenylated xanthones, phenylxanthones, and xanthonolignoids from 11 Hypericum plants and one Triadenum plant collected in Japan, China, and Uzbekistan or cultivated in Japan. This review summarizes their chemical structures and biological activities.
... The nuclear ribosomal internal transcribed spacer (nrITS) region or a part of it (ITS2) is one of the most frequently used nuclear markers for the identification and the phylogenetic reconstructions at the species level or even below (Li et al., 2011;Cheng et al., 2016). So far, the nrITS region has been used for inferring phylogenies (Meseguer et al., 2013;Nurk et al., 2013) and for species authentication in the genus Hypericum (Costa et al., 2016;Raclariu et al., 2017). ...
... The phylogenetic reconstruction obtained by NJ, UPGMA and MP methods using the nrITS region was overall in agreement with that observed in other studies of Hypericum species (Meseguer et al., 2013;Nurk et al., 2013). All the dendrograms exhibited similar topologies, therefore only the UPGMA reconstruction is presented here (Fig. 4). ...
Hypericum perforatum has plenty of uses in traditional medicine and is the source of top-selling herbal drugs and food supplements. The secondary metabolite chemistry for most of the nearly 500 Hypericum taxa is still unknown, even though they are used interchangeably. In the present study, we characterized four Hypericum populations from Achaia, Greece, belonging to H. perforatum ssp. veronense, H. perfoliatum, H. triquetrifolium, and an uninvestigated taxon, H. empetrifolium ssp. empetrifolium, in terms of their essential oils and polar bioactives in methanolic extracts via GC-MS, LC-HRMS, LC-DAD-MS, and HPLC-DAD. We also performed sequence analysis of nrITS to explore the genetic profile of these taxa and to examine whether their genotype is correlated to the metabolome. Sixty-three non-volatile compounds, phloroglucinols in their majority, and over one hundred (113) volatiles, mostly sesqui- and mono- terpenes, were detected. The concentration of the major polar constituents varied greatly among samples. In particular, phloroglucinols' diversity and abundance in H. empetrifolium ssp. empetrifolium was remarkable. The PCA and Biplot analysis revealed the contribution of each compound to the total chemodiversity and also revealed certain compounds that contribute to the discrimination of the samples. Sequence analysis of nrITS revealed different genetic profiles and markers which can be used for the identification of the four Hypericum taxa. The Mantel test showed a relatively strong correlation between the genetic profile and the volatile compounds and low with the main polar metabolites.
... The genus Hypericum belongs to the Hypericaceae family and comprises approximately 500 species of herbs, shrubs, and small trees, most of which are placed in temperate regions of the world (Crockett and Robson, 2011;Nürk et al., 2013). Previous phytochemical studies on Hypericum plants revealed the presence of polycyclic polyprenylated acylphloroglucinols (PPAPs) (Ciochina and Grossman, 2006;Yang et al., 2018), simple phloroglucinols , xanthones (Tanaka et al., 2009;Xu et al., 2016), flavonoids (Porzel et al., 2014), naphthodianthrones (Farag and Wessjohann, 2012), and benzophenones as major components. ...
... Based on morphological character analyses, H. elatoides was classified as either section Roscyna (Spach) R. Keller (Robson, 1977) or section Ascyreia Choisy (Robson, 2001). Molecular phylogenetic analyses showed that H. elatoides was closely related to H. ascyron L. (a member of section Roscyna), while section Roscyna nested with the large section Ascyreia (Meseguer et al., 2013;Nürk et al., 2013). Our results demonstrated that H. elatoides contained large amounts of flavonoids , flavanols derivatives (4-8), xanthones (9-13), and phloroglucinol derivative (1), whereas several characteristic secondary metabolites such as hypericin, pseudohypericin, mangiferin, amentoflavone, and I3, II8-biapigenin, were not found in H. elatoides, which is most similar to the phytochemical profiles of the species from the sections Ascyreia and Roscyna (Kitanov and Nedialkov, 1998;Kitanov, 2001;Crockett and Robson, 2011;Camas et al., 2014;Cirak et al., 2016). ...
... Among apomorphic characters belong glandular structures, namely translucent cavities and especially dark glands that are present in members of the advanced taxonomic sections. The dark glands evolved firstly in reproductive parts and later on in vegetative parts in species belonging to core Hypericum (Nürk et al., 2013). ...
... Naphthodianthrones are unique compounds of the genus Hypericum that are produced by representatives of phylogenetically younger sections. While H. kouytchense and H. monogynum from primitive section Ascyreia (Crockett and Robson, 2011) and H. canariense from monotypic section Webbia did not produce hypericin and its derivatives, species belonging to clade core Hypericum (Nürk et al., 2013), H. perforatum, H. maculatum, H. erectum, H. tetrapterum and H. humifusum, accumulated naphthodianthrones. Similar pattern of distribution among sections was reported by Kitanov (2001). ...
Shoot cultures of eight Hypericum species belonging to the sections Hypericum, Oligostema, Ascyreia and Webbia were evaluated for their phytochemical profiles by high-performance liquid chromatography. In total, 17 secondary metabolites assigned to the groups of anthraquinones, phloroglucinols, hydroxycinnamic acids and flavonoids were detected. Furthermore, the elicitation potential of 18 biotic factors derived from saccharides, endophytic fungi and Agrobacterium rhizogenes was examined and statistically analysed with the paired two-sample t-test and principal component analysis. The production of naphthodianthrones and emodin was predominantly stimulated by elicitors derived from Fusarium oxysporum and Trichoderma crassum, while Piriformospora indica promoted the phloroglucinols production. Among flavonoids, the aglycone amentoflavone was readily increased by several elicitors up to 15.7-fold in H. humifusum treated by potato-dextrose broth. However, the chlorogenic acid proved to be the most susceptible metabolite to elicitation, when 31.7-times increase was detected in H. maculatum shoots upon D-glucose treatment. In spite of several biotic factors have been tested, no metabolite was commonly induced in all Hypericum spp. as a response to elicitor treatments.
... A total of 55 Hypericum species were included in the analysis dataset, with ITS sequences obtained from NCBI (https://www.ncbi.nlm.nih.gov/). These 55 species represented 34 taxa of the genus Hypericum (Table 1), with 1-10 species selected as representatives for each taxon (Nürk et al. 2013). However, species of sect. ...
Hypericum liboense M.T.An & T.R.Wu, sp. nov. (Hypericaceae) is a newly described species found in the Maolan National Nature Reserve of Guizhou Province, where it grows in rocky habitats without soil on karst mountain tops. In this study, key morphological characters were compared between the new species and the other known Hypericum species of Hypericaceae. DNA sequences were extracted from the leaves of the new species, with nuclear gene sequences (ITS) generated to reconstruct phylogenetic trees and describe its phylogenetic position in relation to other species of Hypericum . Our results show that the proposed new species has the typical characteristics of the genus Hypericum in morphology being similar to Hypericum monogynum , but differing in its sessile and semi-clasped leaves, long elliptical to long circular leaf blades, thickly papery to thinly leathery, with entire and wavy leaf margins. The abaxial side of the leaves is covered with white powder, giving them a grey-white appearance. The main lateral veins of the leaves are 8–15-paired, and the midvein on both sides is convex. The main lateral veins and midvein branch are conspicuous, with tertiary venation forming a network on the leaf surface and appearing prominently sunken. The inflorescences are 1–3-flowered, with a large calyx and conspicuous veins. The molecular phylogenetic analysis (PP = 1.00) provided substantial evidence for the proposition of H. liboense as a new species within Hypericum . Morphological and molecular evidence is presented, corroborating the proposition of the new species, including a comprehensive account of the distinctive morphological attributes of H. liboense , along with its key distinguishing features from similar species.
... Hypericum Tourn. ex L. is the largest genus in Hypericaceae, comprising over 500 species of small trees, shrubs, and herbs (Crockett and Robson, 2011;Nürk et al., 2013). Several species of Hypericum have been used as traditional medicines, especially in China, with various described biological activities such as antibacterial, antioxidant, cytotoxic, anti-inflammatory, antihyperglycemic, enzyme-inhibition, and antifungal effects. ...
... Eastern Turkey and Transcaucasia are considered to be a kind of distribution center for the genus (Robson, 2010a(Robson, , 2010b(Robson, , 2012Aslan, 2012;Yüce-Babacan et al., 2017;Başköse & Savran, 2018;Dirmenci & Robson, 2019;Özbek et al., 2019;Dönmez, 2000;Duman & Çakır-Dındar, 2020;Özgişi & Ocak, 2021). The distribution and configuration of the glands on both sepals and petals is a useful and relevant character in the infrageneric classification of Hypericum (Robson, 1967;Nürk et al., 2013). ...
Firat, M. & H. Eroğlu (2023). Hypericum celikaensis (Hypericaceae), a new species from southeastern Anatolia (Adıyaman–Turkey). Candollea 78: 79–87. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2023v781a7
A new species, Hypericum celikaensis Fırat & Eroğlu, belonging to section Arthrophyllum Jaub. & Spach, is described and illustrated from Çelikhan/Adıyaman Province, Turkey. The species is similar to H. rupestre Jaub. & Spach and H. cardiophyllum Boiss. However, it is easily distinguished from H. rupestre by its two-lined stem and the free sepals (at base) with fewer black glands. It differs from H. cardiophyllum in having sessile black glands on sepals and asymmetrically retuse petals. In addition, the pollen and the seeds of both H. celikaensis and H. rupestre are characterized. An amended identification key to the species of Hypericum sect. Arthrophyllum in Turkey is provided, as well as detailed pictures of living plants.
Received: October 4, 2022; Accepted: May 16, 2023; First published online: June 13, 2023
... Similarly, hyperforin, together with its analogues adhyperforin or hyperfirin, were co-localized in the translucent pale cavities (Kusari et al., 2015;Kucharıḱováet al., 2016;Rizzo et al., 2019;Revuru et al., 2020). Since only members of the sections belonging to clade core Hypericum produce hypericins (Nürk et al., 2013), the application of naphthodianthrones as potential stress-induced markers in metabolic phenotyping is limited. Nevertheless, numerous studies have been focused on improvement of the Hypericum spp. ...
In this review we summarize the current knowledge about the changes in Hypericum secondary metabolism induced by biotic/abiotic stressors. It is known that the extreme environmental conditions activate signaling pathways leading to triggering of enzymatic and non-enzymatic defense systems, which stimulate production of secondary metabolites with antioxidant and protective effects. Due to several groups of bioactive compounds including naphthodianthrones, acylphloroglucinols, flavonoids, and phenylpropanes, the world-wide Hypericum perforatum represents a high-value medicinal crop of Hypericum genus, which belongs to the most diverse genera within flowering plants. The summary of the up-to-date knowledge reveals a relationship between the level of defense-related phenolic compounds and interspecific differences in the stress tolerance. The chlorogenic acid, and flavonoids, namely the amentoflavone, quercetin or kaempferol glycosides have been reported as the most defense-related metabolites associated with plant tolerance against stressful environment including temperature, light, and drought, in association with the biotic stimuli resulting from plant-microbe interactions. As an example, the species-specific cold-induced phenolics profiles of 10 Hypericum representatives of different provenances cultured in vitro are illustrated in the case-study. Principal component analysis revealed a relationship between the level of defense-related phenolic compounds and interspecific differences in the stress tolerance indicating a link between the provenance of Hypericum species and inherent mechanisms of cold tolerance. The underlying metabolome alterations along with the changes in the activities of ROS-scavenging enzymes, and non-enzymatic physiological markers are discussed. Given these data it can be anticipated that some Hypericum species native to divergent habitats, with interesting high-value secondary metabolite composition and predicted high tolerance to biotic/abiotic stresses would attract the attention as valuable sources of bioactive compounds for many medicinal purposes.
... However, the wide range of questions that can be addressed through the inference of ancestral states or change trajectories of key characters in phylogenetic trees is fascinating. The reconstruction of the probable ancestral states of organisms has been used to reveal homologies between characters; study morphological conservatism and homoplasia; check if there is neutral evolution or functional divergence in any specific system; detect correlated transitions between characters in coevolutionary lineages; examine the origin of adaptations; evaluate variations in diversification rates; re-evaluate past classifications; investigate the ancient characteristics of life on Earth, as well as to evaluate ecological and evolutionary hypotheses (Collins et al. 1994;Cunha et al. 2015;Cunningham et al. 1998;de Oliveira et al. 2014;Givnish et al. 2005, Horn et al. 2009Nurk et al. 2013;Pagel et al. 2004;Ricklefs 2007;Ronquist 2004;Royer-Carenzi et al. 2013;Schäffer et al. 2010;Simpson 2010;Soltis et al. 2013;Webster et al. 2012;Wu et al. 2015). ...
The chapter exposes the performance of Acacia melanoxylon wood for pulping production, regarding yields and kappa number but also the pulp and paper properties. The use of spectroscopy techniques is also emphasized.
... John's Wort). More than 400 species have been determined in Hypericum genus (Nürk et al., 2013). Different activities has been reported for Hypericum species including antioxidant, anti-cancer, anti-depressive and anti-viral activities (Sotak et al., 2016). ...
Hypericum perforatum is a valuable medicinal plant with anti-depressant activity. Hypericin is the major compound responsible for such activity. In the present study, the effect of four nano-capsulated hormones of 2,4-epibrassinolide, spermidine, salycilic acid and cycocel were investigated on the amount of hypericin based on HPLC analysis in two locations (Saman and Isfahan). For each hormone, the normal form was also compared with nano form. The expression patterns of the key genes ( Hyp-1, pks1, pks 2) for hypericin production was also evaluated using qRT-PCR. Moreover, GC-MS analysis was also performed for determination of the compounds in studied treatments. The major compounds were germacrene D (3.29–33.53%), β-caryophyllene (0-4.08) and α-longipinene (0-24.05%). In most cases, nano-hormones led to increase in these components. Significant changes were obtained in expression of key genes in hypericin synthesis as a result of nano-hormones treatments in Isfahan site. Overall, nano-hormones revealed higher increase in expression of all genes as compared with normal hormones in this site. The expression of Hyp-1 , Pks1 and Pks2 was significantly increased using spermidine, 24-epibrassinolide and cycocel in Isfahan location in both nano-hormones and normal ones, while the expression of Hyp-1 was decreased in SA treatment in Isfahan location. Based on HPLC analysis, hypericin ranged from 0.21 in control to 0.51 mg 100 g − 1 DW in nano-SA in Isfahan site. Finally, the expression of the key genes were mostly elevated in colder climates and nano-form formulation.
... Taken together, the difficulties to separate and clarify the exact sequence of zygophylloides. Maps were created using the elevation above sea level data from the WorldClim climate layers (Hijmans et al., 2005), with a spatial resolution of 30 using the raster library v2.8-19 (Hijmans, 2019) early branching events is a characteristic pattern in rapid evolutionary radiations among the plant tree of life, and has been found at various phylogenetic levels, for example, in Saxifragales (Fishbein et al., 2001), within the genus Hypericum (Hypericaceae; Nürk et al., 2013;Nürk et al., 2015) and in a group of South American Lithospermum (Boraginaceae; Weigend et al., 2010). It remains to be seen, however, whether analyses of nuclear markers apart from ITS support the patterns retrieved here. ...
... DNA barcoding studies of the genus Hypericum have focused on the ITS region for phylogenetic analysis [22][23][24][25][26], detection of Hypericum species in herbal products [27][28][29][30][31], and species identification [32][33][34]. However, the low discrimination power and the multi-copy nature of this nuclear region complicate the analysis, so the use of plastid regions with a fast evolutionary rate is proposed [22,23,25,27,33]. ...
Plants of the genus Hypericum, commonly known as “St. Johnʼs wort” (“spathohorto” or “valsamo” in Greek), have been used since antiquity for their therapeutic properties. Wild-harvested Hypericum plants are still popular today in herbal medicines, commercially exploited due to their bioactive compounds, hypericin and hyperforin, which have antidepressant, antimicrobial and antiviral activity. Species identification of commercial products is therefore important and DNA barcoding, a molecular method that uses small sequences of organismsʼ genome as barcodes, can be useful in this direction. In this study, we collected plants of the genus Hypericum that grow wild in North-Eastern Greece and explored the efficiency of matK, and trnH-psbA regions as DNA barcodes for their identification. We focused on 5 taxa, namely H. aucheri, H. montbretii, H. olympicum, H. perforatum subsp. perforatum, and H. thasium, the latter a rare Balkan endemic species collected for the first time from mainland Greece. matK (using the genus-specific primers designed herein), trnH-psbA, and their combination were effectively used for the identification of the 5 Hypericum taxa and the discrimination of different H. perforatum subsp. perforatum populations. These barcodes were also able to discriminate Greek populations of H. perforatum, H. aucheri, H. montbretii, and H. olympicum from populations of the same species growing in other countries.
... The genus Hypericum (Hypericaceae family) consists of 496 worldwide species (Nürk et al., 2013;Ruhfel et al., 2013), of which 17 species have been reported from Iran and most of them have antioxidants (Silva et al., 2005), antiviral (Birt et al., 2009), an antidepressant (Butterweck, 2003) and anticancer compounds (Agostinis et al., 2002). Most of these medicinal properties are due to the presence of a group of hydrosoluble secondary metabolites, which are often present in the flowers of this perennial herb (Lazzara et al., 2015). ...
p>The traditional medicinal herb, Hypericum perforatum L. has been popular for its pharmaceutical and coloring wealth since the ancient era. A secondary metabolite from the group of naphthodianthrones in Hypericum spp . named hypericin is responsible for the antidepression, anticancer, and antiviral characteristics of this herb. It has been found that several genes are involved in the biosynthesis pathway of hypericin. The hyp-1 gene is participating in this biosynthesis path through the conversion of emodin to hypericin. The naphthodianthrones (hypericin and pseudohypericin) in Hypericum are synthesized through the polyketide pathway. In the plants, the enzyme complexes named polyketide synthase (PKS) catalyzes the reactions of polyketide pathways. The genes HpPKS1 and HpPKS2 are encoding PKS enzyme complexes. In this research, the relative expression of hyp-1 , HpPKS1, and HpPKS2 genes was compared in root and leaves of Hypericum perforatum and H. androsaemum L., before and after flowering under urea fertilization at 24, 48 and 72 hours after irrigation. The highest expression level of all three genes was observed after flowering in the samples of H. perforatum that were fertilized 72 hours after irrigation by 1 g l<sup>-1</sup> urea ( hyp-1 in roots; HpPKS1 and HpPKS2 in leaves). The relative expression of hyp-1 in the root was greater than in the leaves, but HpPKS1 and HpPKS2 expression in leaves was higher than in root. The relative expression of all three genes in H. perforatum was higher than in H. androsaemum . By increasing the interval between urea fertilization and irrigation, the relative expression of genes had an increasing trend, also by increasing the amount of urea fertilizer, relative gene expression was increased.</p
... However, the wide range of questions that can be addressed through the inference of ancestral states or change trajectories of key characters in phylogenetic trees is fascinating. The reconstruction of the probable ancestral states of organisms has been used to reveal homologies between characters; study morphological conservatism and homoplasia; check if there is neutral evolution or functional divergence in any specific system; detect correlated transitions between characters in coevolutionary lineages; examine the origin of adaptations; evaluate variations in diversification rates; re-evaluate past classifications; investigate the ancient characteristics of life on Earth, as well as to evaluate ecological and evolutionary hypotheses (Collins et al. 1994;Cunha et al. 2015;Cunningham et al. 1998;de Oliveira et al. 2014;Givnish et al. 2005, Horn et al. 2009Nurk et al. 2013;Pagel et al. 2004;Ricklefs 2007;Ronquist 2004;Royer-Carenzi et al. 2013;Schäffer et al. 2010;Simpson 2010;Soltis et al. 2013;Webster et al. 2012;Wu et al. 2015). ...
... However, the wide range of questions that can be addressed through the inference of ancestral states or change trajectories of key characters in phylogenetic trees is fascinating. The reconstruction of the probable ancestral states of organisms has been used to reveal homologies between characters; study morphological conservatism and homoplasia; check if there is neutral evolution or functional divergence in any specific system; detect correlated transitions between characters in coevolutionary lineages; examine the origin of adaptations; evaluate variations in diversification rates; re-evaluate past classifications; investigate the ancient characteristics of life on Earth, as well as to evaluate ecological and evolutionary hypotheses (Collins et al. 1994;Cunha et al. 2015;Cunningham et al. 1998;de Oliveira et al. 2014;Givnish et al. 2005, Horn et al. 2009Nurk et al. 2013;Pagel et al. 2004;Ricklefs 2007;Ronquist 2004;Royer-Carenzi et al. 2013;Schäffer et al. 2010;Simpson 2010;Soltis et al. 2013;Webster et al. 2012;Wu et al. 2015). ...
... There is considerable taxonomic information available about the genus Hypericum from both morphological studies captured in Robson's monograph [22], and complementary chemical [23,24] and molecular studies based primarily on the ITS region [25][26][27]. This information immediately indicates a problem for DNA barcoding-this is a very large genus comprising some 490 species assigned to 36 Sections [22,28]. ...
DNA barcoding is a widely accepted technique for the identification of plant materials, and its application to the authentication of commercial medicinal plants has attracted significant attention. The incorporation of DNA-based technologies into the quality testing protocols of international pharmacopoeias represents a step-change in status, requiring the establishment of standardized, reliable and reproducible methods. The process by which this can be achieved for any herbal medicine is described, using Hypericum perforatum L. (St John's Wort) and potential adulterant Hypericum species as a case study. A range of practical issues are considered including quality control of DNA sequences from public repositories and the construction of individual curated databases, choice of DNA barcode region(s) and the identification of informative polymorphic nucleotide sequences. A decision tree informs the structure of the manuscript and provides a template to guide the development of future DNA barcode tests for herbals.
... However, to get there, a sectional classification of the genus still needs to undergo deep rearrangements. This includes the South American species of Hypericum that are still being included within the two largest non-monophyletic (Meseguer & al., 2013;Nürk & al., 2013a) sections of the genus: sect. Brathys (Mutis ex L.f.) Choisy and sect. ...
An updated taxonomic and nomenclatural framework is essential to develop most biological research. To stabilize the application of Hypericum names and avoid future problems, we critically reviewed the protologues, the main Floras in which the studied names are listed, and the types of 84 names described for non‐Andean South America (Argentina, Brazil, Paraguay, Uruguay). Application of the term holotype is corrected to lectotype for 18 names, and type is corrected to lectotype for six names (“inadvertent lectotypifications”). For H. nudicaule the term type is corrected to neotype, for H. paraguense the term lectotype is corrected to neotype, and for H. polyanthemum the term isotype is corrected to neotype (“inadvertent neotypifications”). For 24 names, lectotypifications are provided, including one re‐lectotypification (H. brasiliense var. angustifolium ) and 19 second‐step lectotypifications. Neotypes are designated for four names (H. cyathifolium , H. lorentzianum , H. meridionale , H. sellowianum ). Five new synonyms are proposed (H. campestre subsp. pauciflorum , H. campestre subsp. tenue , H. rigidum subsp. bracteatum , H. rigidum subsp. meridionale , H. rigidum subsp. sellowianum ), and two superfluous names are detected for the first time (H. bolivianum , H. connatum var. obscurum ).
... Taken together, the difficulties to separate and clarify the exact sequence of zygophylloides. Maps were created using the elevation above sea level data from the WorldClim climate layers (Hijmans et al., 2005), with a spatial resolution of 30 using the raster library v2.8-19 (Hijmans, 2019) early branching events is a characteristic pattern in rapid evolutionary radiations among the plant tree of life, and has been found at various phylogenetic levels, for example, in Saxifragales (Fishbein et al., 2001), within the genus Hypericum (Hypericaceae; Nürk et al., 2013;Nürk et al., 2015) and in a group of South American Lithospermum (Boraginaceae; Weigend et al., 2010). It remains to be seen, however, whether analyses of nuclear markers apart from ITS support the patterns retrieved here. ...
Background Drosanthemum, the only genus of the tribe Drosanthemeae, is widespread over the Greater Cape Floristic Region in southern Africa. With 114 recognized species, Drosanthemum, together with the highly succulent and species-rich tribe Ruschieae, constitute the ‘core ruschioids’ in Aizoaceae. Within Drosanthemum, nine subgenera have been described based on flower and fruit morphology. Their phylogenetic relationships, however, have not yet been investigated, hampering understanding of monophyletic entities and patterns of geographic distribution. Methods Using chloroplast and nuclear DNA sequence data, we performed network- and tree-based phylogenetic analyses of 73 species of Drosanthemum with multiple accessions for widespread species. A well-curated, geo-referenced occurrence dataset comprising the 134 genetically analysed and 863 further accessions was used to describe the distributional ranges of intrageneric lineages and the genus as a whole. Results Phylogenetic inference supports nine clades within Drosanthemum, seven of which group in two major clades, while the remaining two show ambiguous affinities. The nine clades are generally congruent to previously described subgenera within Drosanthemum, with exceptions such as cryptic species. In-depth analyses of sequence patterns in each gene region were used to reveal phylogenetic affinities inside the retrieved clades in more detail. We observe a complex distribution pattern including widespread, species-rich clades expanding into arid habitats of the interior (subgenera Drosanthemum p.p., Vespertina, Xamera) that are genetically and morphologically diverse. In contrast, less species-rich, genetically less divergent, and morphologically unique lineages are restricted to the central Cape region and more mesic conditions (Decidua, Necopina, Ossicula, Quastea, Quadrata, Speciosa). Our results suggest that the main lineages arose from an initial rapid radiation, with subsequent diversification in some clades.
... Sixteen Tunisian populations of H. humifusum L. were evaluated for their genetic variability using isomeric and random-amplified polymorphic DNA (RAPD) markers (Bejaoui et al., 2010(Bejaoui et al., , 2012. Furthermore, internal transcribed spacer (Nürk et al., 2013;Pilepic et al., 2011) and RFLP (Pilepic et al., 2010) techniques were used assess the extent of phylogenetic relationships in several sections of Hypericum genus. The following molecular studies have revealed high genetic diversity and excess heterozygosity within populations supporting an outbreeding mating system and low gene flow. ...
The genus Hypericum (Hypericaceae) consists of 484 species from 36 sections with worldwide distribution in different areas. Turkey is considered as hot spot for diversity of Hypericum genus. Despite numerous publications, Hypericum species still attracted considerable scientific interest due to pharmaceutically relevant secondary metabolites: naphthodianthrones, acylphloroglucinol derivatives, phenolic acids, flavonoid glycosides, biflavonoids, and some other valuable constituents. Phytochemical investigations carried out on different Hypericum species provided highly heterogeneous results. The content of bioactive compounds varies significantly due to many internal and external factors, including plant organs, phenological stage, genetic profile, environmental abiotic and biotic factors, such as growing site, light, temperature, radiation, soil drought and salinity, pathogens, and herbivores attack. The variations in content of bioactive compounds in plants are regarded as the main problem in the standardization of Hypericum-derived pharmaceuticals and dietary supplements. The review discusses the main factors contributing to the variations of bioactive compounds and what kind of modulations can increase quality of Hypericum raw material.
... Since a test for commercial adulterants does not need to include rare Hypericum species that bear little resemblance to H. perforatum, the database of just twenty species included several close relatives from the Section Hypericum (H. attenuatum, H. maculatum, H. tetrapterum, H. undulatum) [37]. ...
There is considerable potential for the use of DNA barcoding methods to authenticate raw medicinal plant materials, but their application to testing commercial products has been controversial. A simple PCR test targeting species-specific sequences within the nuclear ribosomal internal transcribed spacer (ITS) region was adapted to screen commercial products for the presence of Hypericum perforatum L. material. DNA differing widely in amount and extent of fragmentation was detected in a number of product types. Two assays were designed to further analyse this DNA using a curated database of selected Hypericum ITS sequences: A qPCR assay based on a species-specific primer pair spanning the ITS1 and ITS2 regions, using synthetic DNA reference standards for DNA quantitation and a Next Generation Sequencing (NGS) assay separately targeting the ITS1 and ITS2 regions. The ability of the assays to detect H. perforatum DNA sequences in processed medicines was investigated. Out of twenty different matrices tested, both assays detected H. perforatum DNA in five samples with more than 103 ITS copies µL−1 DNA extract, whilst the qPCR assay was also able to detect lower levels of DNA in two further samples. The NGS assay confirmed that H. perforatum was the major species in all five positive samples, though trace contaminants were also detected.
... To ensure as complete sampling as possible for the páramo endemics and related taxa, we used a previously published time-calibrated phylogeny, which has extensive sampling of the New World lineages (Nürk et al., 2018). Previous work has demonstrated a close association between arborescence and tropical montane occurrences in African mountains and the Andes (Nürk et al., 2013a) and elevated species richness associated with the very recent Pliocene / Quaternary radiation in the Andes, a radiation encompassing a disparate array of growth forms typical of tropical alpine sky island plant groups (Nürk et al., 2013b). ...
The following Supporting Information is available for this article:
Table S1 Voucher – Information on species and sequence references included in the study, and coding of characters (distribution, life history, and growth form).
Table S2 Comparative diversification rate analysis: model specification and model fit (BayesRate). Table S3 Sampling fractions: exploratory rate heterogeneity analysis (BAMM).
Table S4 Plant height: growth form (phenotypic) evolution analysis detailing model fit (OUwie).
Figures S1–S4 Secondary woodiness – time trees incl. tip names and clade assignment detailing life history analysis comparing ML to SCM ancestral state estimations (ace & make.simmap), and island/non-island mappings for Echium (Fig. S1), Hypericum (Fig. S2), Lupinus (Fig. S3), and Silverswords–Tarweeds (Fig. S4).
Methods S1 Clade specific tree and trait data – Phylogenetic reconstruction and age estimation (BEAST), fossils used for calibration, full references for trait data.
Notes S1 Hypericum traits – details on potential biases using mean plant height in the group.
... However, the wide range of questions that can be addressed through the inference of ancestral states or change trajectories of key characters in phylogenetic trees is fascinating. The reconstruction of the probable ancestral states of organisms has been used to reveal homologies between characters; study morphological conservatism and homoplasia; check if there is neutral evolution or functional divergence in any specific system; detect correlated transitions between characters in coevolutionary lineages; examine the origin of adaptations; evaluate variations in diversification rates; re-evaluate past classifications; investigate the ancient characteristics of life on Earth, as well as to evaluate ecological and evolutionary hypotheses (Collins et al. 1994;Cunha et al. 2015;Cunningham et al. 1998;de Oliveira et al. 2014;Givnish et al. 2005, Horn et al. 2009Nurk et al. 2013;Pagel et al. 2004;Ricklefs 2007;Ronquist 2004;Royer-Carenzi et al. 2013;Schäffer et al. 2010;Simpson 2010;Soltis et al. 2013;Webster et al. 2012;Wu et al. 2015). ...
... The revisional studies of the genus at both sectional and species levels were conducted by N.K.B. Robson (1967Robson ( , 1977Robson ( , 1981Robson ( , 1985Robson ( , 1987Robson ( , 1988Robson ( , 1990Robson ( , 1993Robson ( , 1996Robson ( , 2001Robson ( , 2002Robson ( , 2003Robson ( , 2006Robson ( , 2010aRobson ( , 2010bRobson ( , 2012Robson ( , and 2016. The taxonomic (Stevens 2007, Crockett and Robson 2011, Robson 2012, Alonso et al. 2013), morphogenetic (Çırak et al. 2006, Ayan et al. 2007), paleobiologic (Meseguer & Sanmartín 2012), and phylogenetic (Meseguer et al. 2013, Nürk et al. 2013) studies on Hypericum were conducted by different authors. Moreover, several new species which belong to the genus were described in the last decade (Heenan 2008, Ocak et al. 2009, Keller & Crockett 2015, Vogel Ely et al. 2015, Wilhelm & Rericha 2016, Babacan et al. 2017. ...
Hypericum bilgehan-bilgilii is here described and illustrated as a new species of section Triadenioides, from the Southern Anatolia, Turkey. Distribution map, habitat and ecology, etymology, the Turkish name for the new species, and dichotomous key are given. The new species is compared with morphologically close species, H. ternatum and H. pallens.
In this research paper, it is reported the preparation and characterization of four types of blended cotton-polyester based textile materials in different ratio dyed with four kinds of natural dyes of agro waste (walnut shell, onion peel) and wildflowers (tansy, Hypericum) with/without mordants as antibacterial and antifungal species for shoe materials. The dyed samples were spectrophotometrically measured and the results were obtained as color strength (K/S) as well as CIE Lab values. As a result, dyed fabrics with natural dyes showed yellow, gray, orange and brown colors. With the help of a mordant, aluminum-potassium, it was obtained natural, not distorted shades of this color, and with the addition of copper sulfate, it showed changing yell ow to light green, orange to dark red, gray to a darker shade of gray and the last brown to a darker color. The dyed samples were tested for color fastness to circle rubbing and found satisfactory results. The fabrics dyed only with natural dyes and treated with natural dye and mordants were evaluated for antibacterial and antifungal properties against Escherichia coli, Staphylococcus aureus and Candida albicans. The results indicated that fabrics treated with these natural dyes and mordants had excellent antibacterial and antifungal activity. All natural dyes and mordants used in this study were the most effective and showed the maximum inhibition zone, indicating the best antimicrobial and antifungal activity against tested microbes. The results showed that all these natural dyes can provide some antibacterial and antifungal activity on mixed fabrics.
Phytochemical investigation on the 90% EtOH extract of the air-dried aerial parts of Hypericum ascyron resulted in the isolation of three new polycyclic polyprenylated derivatives ascyronines A-C (1-3). Structural elucidation of all the compounds was performed by spectral methods such as 1D and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy. All the polycyclic polyprenylated acylphloroglucinols were evaluated for their antidepressant activity by inhibiting the reuptake of tritiated serotonin ([3H]-5-HT) and noradrenalinet ([3H]-NE) in rat brain synaptosomes. Compounds 2 and 3 exhibited weak antidepressant activities in the [3H]-5-HT mode.
The seed morphology of 40 taxa within the genus Hypericum (Hypericaceae) from China, representing 9 sections of the genus, was examined using both Light and Scanning Electron Microscopy to evaluate the taxonomic relevance of macro‐ and micro‐morphological features. Details articulating variation in seed size, color, shape, appendages, and seed coat ornamentation are described, illustrated, and compared, and their taxonomic importance is discussed. Seeds were generally brown in color and cylindric‐ellipsoid to prolonged cylindric in shape. Seed size displayed wide variation, ranging from 0.37–1.91 mm in length and 0.12–0.75 mm in width. Seed appendages were observed as a characteristic morphological feature. Seed surface ornamentation has high phenotypic plasticity, and four types (reticulate, foveolate, papillose, and ribbed) can be recognized. In general, seed color and shape have limited taxonomic significance. However, some other features represent informative characters that can be used efficiently in distinguishing the studied taxa at the section and/or species levels. The findings illustrate that considerable taxonomic knowledge can be obtained by investigating the seed features of Hypericum , and the use of Scanning Electron Microscopy can reveal inconspicuous morphological affinities among species and play a role in taxonomic and systematic studies of the genus Hypericum .
Research Highlights
Macro‐ and micro‐morphological features of seeds of 40 Hypericum taxa from China were examined using Light and Scanning Electron Microscopy, providing the first broad study regarding seed morphology for Hypericum from China.
Details and variations of seed size, shape, color, surface ornamentation, and appendages are fully presented.
Seed features and their variation have important taxonomic significance at the section and/or species levels within Hypericum .
Calophyllum soulattri Burm. f. (1768) is an evergreen tree native to Southeast Asia, Australia, and the Solomon Islands. It is known for its medicinal uses and has been utilized in traditional folk medicine. However, genomic resources for this species are still unavailable. In this study, we sequenced and assembled the first complete chloroplast genome of C. soulattri using next-generation sequencing data. The chloroplast genome of C. soulattri is 161,381 bp in length with a total GC content of 36.36%. The chloroplast genome contains a large single copy (LSC) region of 88,680 bp, a small single copy (SSC) region of 17,453 bp, and two inverted repeat (IR) regions of 27,624 bp each. Furthermore, the chloroplast genome has 131 genes, which include 86 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis indicated that C. soulattri is clustered in the same branch with C. inophyllum and is closely related to Mesua ferrea.
St. John’s wort is one of the most amazing and medicinal plants of interest worldwide which is nowadays known as a certain cure for depression. However, the presence of dormancy and low seed germination is a barrier to the progress of its breeding programs. Despite the richness of the plant’s genetic resources, there are only a few studies reported on its propagation and maintenance in Iran, most of which do not mention the geographical origin of the used seeds or explants. The current study was carried out aiming to evaluate in vitro plant propagation of eight Iranian endemic populations of St. John’s wort seeds which belonged to different geographical origins, emphasizing seed dormancy phenomena.
Following the collection of eight populations of St. John’s wort (Hypericum perforatum L.) seeds from different geographical regions of Iran, the Murashige and Skoog culture media (common salt mixture as a control, MS improved with Gibberellic acid and a modified combination of MS) was used in an effort to investigate the effect of culture medium as well as seed collection locations on the germination percentage of these populations.
The results showed that the interaction between the seed collection locations and the culture medium on seed germination was significant at P<0.01. Besides, the effect of changing culture media on seed germination was significant in all populations at P<0.01, except for Meshkin-Shahr. In other words, the seeds collected from Meshkin-Shahr germinated easily as well as notably under in vitro conditions (97.3% on average), and there was no need either to modify the combination of MS medium or to use Gibberellic acid for seed dormancy elimination. The seeds originated from Challus and Peresk had the lowest germination in the control medium (22.3%, on average). Seeds from Challus and Saqqez had better germination in the media enriched with Gibberellic acid compared to the control and the modified MS media (88% and 65%, respectively). However, less than half of the Parvar seeds germinated in the MS medium improved with GA3, compared to the control. Cultivation of seeds obtained from Fereydunkenar in common MS medium also led to better germination than using GA3 and modifying the combination of medium with 95% and 99% confidence levels, respectively.
The results of the current study demonstrated that the observed difference in seed germination percentage is remarkable in the Iranian endemic St. John’s wort populations under in vitro conditions. Moreover, the variation among national populations was significant. Besides, the response of the seed populations originating from different locations varied with respect to the changes in the culture medium and in the different cases. This shows the considerable effect of the growth location of the maternal plant on the characteristics of the next generation seeds, especially the way they germinate. Hence, it is very important to pay attention to the seed’s origins in the studies and it is investigable.
Keywords: Germination, Gibberellic acid, Medicinal plant
Highlights:
1- This is the first report on the in vitro seed dormancy elimination in the eight Iranian St. John’s wort populations.
2- It was for the first time bringing up the geographical origins of seeds in the national germination studies on the St. John’s wort.
3- It is a quite new method to use a modified combination of MS medium for seed dormancy elimination in the St. John’s wort.
Twenty-seven polycyclic polyprenylated acylphloroglucinols (PPAPs) with diverse skeletons, including seven previously undescribed ones (hyperbeanins A-G), were isolated from the aerial parts of Hypericum beanii. Their structures were established by comprehensive analysis of NMR, HRESIMS, and experimental electronic circular dichroism (ECD) spectra. Hyperbeanin A was a monocyclic polyprenylated acylphloroglucinols (MPAPs) with an unusual spiro-fused cyclopropane ring. Four of the isolated compounds showed obvious hepatoprotective activity against paracetamol-induced HepG2 cell damage at 10 μM. The present results suggested that these compounds would be potential hepatoprotective agents. In addition, the plausible biogenetic pathways of hyperbeanins A-G were proposed, which gave an insight for future biomimetic synthesis of them.
Six dibenzo-1,4-dioxane derivatives (1–6) were isolated from the roots of a Hypericaceous plant Hypericum ascyron. Spectroscopic analyses revealed 2 and 4–6 to be new compounds. The partial racemic natures of 1–3 were concluded by chiral HPLC analyses, while 5 was confirmed to be a racemate. The absolute configurations 1–4 were deduced on the basis of ECD calculations. Biological activity evaluation of the dibenzo-1,4-dioxane derivatives along with two related compounds: hyperdioxanes A (7) and B (8), previously isolated from the same plant material by our group demonstrated that 7 exhibit an anti-HIV activity (IC50 5.3 μM, TI 7.2) while 8 showed an inhibitory effect on IL-1β production (inhibition rate: 72.3% at 6.3 μM) from LPS-stimulated microglial cells.
We report proof-of-principle experiments regarding a dynamic microarray protocol enabling accurate and semi-quantitative DNA analysis for re-sequencing, fingerprinting and genotyping. Single-stranded target molecules hybridise to surface-bound probes during initial gradual cooling with high-fidelity. Real-time tracking of target denaturation (via fluorescence) during a ‘dynamic’ gradual heating phase permits ‘melt-curve’ analysis. The probe most closely matching the target sequence is identified based on the highest melting temperature. We demonstrated a >99% re-sequencing accuracy and a potential detection rate of 1% for SNPs. Experiments employing Hypericum ribosomal ITS regions and HIV genomes illustrated a reliable detection level of 5% plus simultaneous re-sequencing and genotyping. Such performance suggests a range of potential real-world applications involving rapid sequence interrogation, for example, in the Covid-19 pandemic. Guidance is offered towards the development of a commercial platform and dedicated software required to bring this technique into mainstream science.
Hypericum perforatum is among the most commonly used herbal remedies and supplements. The aerial plant parts are often used to treat depression. Due to the lack of genomic information of H. perforatum, the gene networks regulating secondary metabolite synthesis remain unclear. Here, we present a high‐quality genome for H. perforatum with a 2.3‐Mb scaffold N50. The draft assembly covers 91.9% of the predicted genome and represents the fourth sequenced genus in the order Malpighiales. Comparing this sequence with model or related species revealed that Populus trichocarpa and Hevea brasiliensis could be grouped into one branch, while H. perforatum and Linum usitatissimum are grouped in another branch. Combined with transcriptome data, 40 key genes related to melatonin, hyperforin, and hypericin synthesis were screened and analyzed. Five N‐acetylserotonin O‐methyltransferases (HpASMT1‐HpASMT5) were cloned and functionally characterized. Purified HpASMT3 protein converted N‐acetylserotonin into melatonin with a Vmax of about 1.05 pkat/mg protein. HpASMT1 and HpASMT3 overexpression in Arabidopsis mutants caused 1.5‐2‐fold higher melatonin content than in mutant and wild type plants. The endogenous reactive oxygen species (ROS) in transgenic plants was significantly lower than ROS in mutant and wild type plants, suggesting higher drought tolerance. The obtained genomic data offer new resources for further study on the evolution of Hypericaceae family, but also provide a basis for further study of melatonin biosynthetic pathways in other plants.
Hyperterpenoid A (1) and B (2), two pairs of enantiomers, with an unprecedented 6/6/4/6/6 polycyclic skeleton, along with one known compoud hypermonone A (3) were isolated from Hypericum beanii. The racemate (±)-1 and (±)-2 were successfully separated into the two optically pure enantiomers (ee ≥ 99 %) using a preparative HPLC system. Their absolute configurations were elucidated by extensive spectroscopic analyses and single-crystal X-ray diffraction method. The related plausible biogenetic pathways were presented. Compound 1-3 showed significant neuroprotective activity and potential anti-inflammatory activity. The result that (+)-2 and (-)-2 presented different anti-inflammatory properties, may lead us to new discovery of structure activity relationship between racemates, enantiomers, and diastereomers, as well as further research regarding the binding of drugs to target proteins.
Foliar micromorphological characters of 17 species of Hypericum L. belonging to five sections, Androsaemum (Duhamel) Godron, Hypericum , Hirtella Stef. (including 2 subsections: Platyadenum N. Robson et Stenadenum N. Robson), Taeniocarpum Jaub. et Spach. and Drosanthe (Spach) Endl. were examined using scanning electron microscopy (SEM). Based on the current result three types of epidermal cell shape (irregular polygonal, roughly regular rectangular and irregular elliptical); four types of papilla (triangular, with striate wall, finger and star shapes); two main types and three subtypes of epicuticular wax; seven type classes of outer stomatal and peristomatal rims/stomata ledge aperture; three types of wax distribution on the stomata rims/pore/epidermal cell and three types of inner stomatal rims variations (smooth, sinuolate and sinuolate-erose) were identified. The result revealed that leaf micromorphological evidences of Hypericum are taxonomically informative and can be used for separating different sections and species.
Hypericum erectum is an important ethnobotanical medicine in East Asian tradition. To explore the anti-parasitic potential of H. erectum, inhibitory effects on the growth of intracellular parasite Toxoplasma and on the encystation of intestinal parasite Entamoeba were examined. The constituents in H. erectum alcoholic extracts and fractions separated by solvent-partitioning were analysed by high resolution LC–MS. Toxoplasma gondii growth inhibition assay was performed using GFP-labelled T. gondii strain PTG-GFP by measuring the fluorescence intensity. Anti-Toxoplasma drug pyrimethamine was used as a positive control. T. gondii-induced immune reaction was assessed by quantitative PCR and fluorescence microscopy, using co-culture of PTG-GFP and monocyte-macrophage cell line Raw264. The inhibitory effect on the encystation of Entamoeba invadens was measured by flow-cytometry, where paromomycin was used as a positive control. H. erectum methanol (MeOH) extract (50 µg/mL) and ethyl acetate (EtOAc) fraction (50 µg/mL) inhibited the growth of T. gondii, while 50%MeOH extract and hydrophilic fractions were ineffective. Co-culture with T. gondii reduced the viability of macrophages, however macrophages were protected in the presence of H. erectum MeOH extract or EtOAc fraction (above 10 µg/mL). The MeOH extract and EtOAc fraction also effectively suppressed the encystation of E. invadens at 1 mg/mL. Hypericine, a major constituent in MeOH extract and EtOAc fraction, inhibited T. gondii growth and E. invadens encystation. Our results demonstrated that H. erectum effectively inhibited Toxoplasma growth and Entamoeba encystation. These activities are partly mediated by hypericin. In addition, it was suggested the extract and fraction may protect innate immune cells from Toxoplasma-induced damages, thereby enhancing parasite clearance. Further investigation is warranted to address the in vivo effectiveness of H. erectum as an anti-protozoal medicine.
Background
Drosanthemum, the only genus of the tribe Drosanthemeae, is widespread over the Greater Cape Floristic Region in southern Africa. With 114 recognized species, Drosanthemum together with the highly succulent and species-rich tribe Ruschieae constitute the ‘core ruschioids’ in Aizoaceae. Within Drosanthemum , nine subgenera have been described based on flower and fruit morphology. Their phylogenetic relationships, however, have not yet been investigated, hampering understanding of monophyletic entities and patterns of geographic distribution.
Methods
Using chloroplast and nuclear DNA sequence data, we performed network- and tree-based phylogenetic analyses of 73 species represented by multiple accessions of Drosanthemum . A well-curated, geo-referenced occurrence data set comprising the phylogenetically studied and 867 further accessions was used to describe the distributional ranges of intrageneric lineages and the genus as a whole.
Results
Phylogenetic inference supports nine clades within Drosanthemum , seven of them group in two major clades, while the remaining two show ambiguous affinities. The nine clades are generally congruent to previously described subgenera within Drosanthemum , with exceptions such as (pseudo-) cryptic species. In-depth analyses of sequence patterns in each gene region revealed phylogenetic affinities not obvious in the phylogenetic tree. We observe a complex distribution pattern including widespread, species-rich clades expanding into arid habitats of the interior (subgenera Drosanthemum p.p. , Vespertina, Xamera ) that are molecular and morphologically diverse. In contrast, less species-rich, molecularly less divergent, and morphologically unique lineages are restricted to the central Cape region and more mesic conditions ( Decidua , Necopina, Ossicula, Quastea, Quadrata, Speciosa ). Our results suggest initial rapid radiation generating the main lineages, with some clades showing subsequent diversification.
Six new prenylated acylphloroglucinols with menthane moieties, hypascyrins A-E (1-5) and ent-hyphenrone J (6), together with four known analogues, were isolated from Hypericum ascyron roots. Detailed spectroscopic data analyses resulted in the assignment of their structures. The absolute configuration of 1 was deduced by experimental and calculated ECD data, while those of 2-6 were assigned by ECD data analyses as well as chemical conversions. Hypascyrins A (1), C (3), and E (5) and ent-hyphenrone J (6) exhibited antimicrobial activity against MRSA (MIC50 values of 4.0, 8.0, 2.0, and 4.0 μM, respectively) and Bacillus subtilis (MIC values of 4.0, 4.0, 2.0, and 4.0 μM, respectively).
The evolution of secondary (insular) woodiness and the rapid disparification of plant growth forms associated with island radiations show intriguing parallels between oceanic islands and tropical alpine sky islands. However, the evolutionary significance of these phenomena remains poorly understood and the focus of debate.
We explore the evolutionary dynamics of species diversification and trait disparification across evolutionary radiations in contrasting island systems compared with their nonisland relatives. We estimate rates of species diversification, growth form evolution and phenotypic space saturation for the classical oceanic island plant radiations – the Hawaiian silverswords and Macaronesian Echium – and the well‐studied sky island radiations of Lupinus and Hypericum in the Andes.
We show that secondary woodiness is associated with dispersal to islands and with accelerated rates of species diversification, accelerated disparification of plant growth forms and occupancy of greater phenotypic trait space for island clades than their nonisland relatives, on both oceanic and sky islands.
We conclude that secondary woodiness is a prerequisite that could act as a key innovation, manifest as the potential to occupy greater trait space, for plant radiations on island systems in general, further emphasizing the importance of combinations of clade‐specific traits and ecological opportunities in driving adaptive radiations.
Matrix‐free laser desorption/ionization mass spectrometric imaging (LDI‐MSI), matrix‐free laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometric imaging (LDI‐FT‐ICR‐MSI) and a combination of laser microdissection (LMD) and nuclear magnetic resonance spectroscopy (NMR) are used as high‐resolution techniques to analyse the organ‐specific distribution of polycyclic aromatic compounds in plant tissues and to locate these compounds in single plant cells. The ease of detection of these polycyclic aromatic compounds on a cellular level is shown using typical representatives of three plant families: the Hypericaceae, the Musaceae, and the Haemodoraceae. Furthermore, the phenylphenalenone‐type compounds of the Musaceae and Haemodoraceae will be discussed in greater detail.
Computer simulations are useful because they can characterize the expected performance of phylogenetic methods under idealized conditions. However, simulation studies are also subject to several sources of bias that make the results of different simulation studies difficult to interpret and often contradictory. In this study, I examined the performance of 26 commonly used methods of phylogenetic inference for three statistical criteria: consistency, efficiency, and robustness. Methods examined included parsimony (general, weighted, and transversion), maximum likelihood (assuming Jukes-Cantor and Kimura models of DNA substitution), and UPGMA, minimum evolution, and weighted and unweighted least squares (with uncorrected, Jukes-Cantor, Kimura, modified Kimura, and gamma distances). The performance of methods was examined under three models of DNA substitution for four taxa. The branch lengths of the four-taxon trees were varied extensively in this simulation. The results indicate that most methods perform well (i.e., estimate the correct tree ≥95% of the time) over a large portion of the four-taxon parameter space. In general, maximum likelihood performed best, followed by the additive distance methods and the parsimony methods. Lake's method of invariants and UPGMA are, respectively, inefficient and extremely sensitive to branch-length inequalities. In general, differential weighting of character-state transformations increases the performance of methods when the weighting can be applied appropriately. Although methods differ in their consistency, efficiency, and robustness, additional criteria - mainly falsifiability - are extremely important considerations when choosing a method of phylogenetic inference.
With about 470 species Hypericum Linnaeus (1753) is one of the 100 large angiosperm genera that collectively comprise an estimated 22% of angiosperm diversity (Scotland, 2000). The size of such genera means that complete monographic treatments to account for species diversity are time-consuming, costly and labour-intensive. Consequently, the species-level taxonomy of most such groups is poorly known (Frodin 2004, Scotland & Sanderson 2004). This presents a substantial barrier both to the goal of completing the global inventory and to understanding the evolution of the diversity they contain.
The internal transcribed spacer (ITS) region of 18S-26S nuclear ribosomal DNA (nrDNA) has proven to be a useful source of characters for phylogenetic studies in many angiosperm families. The two spacers of this region, ITS-1 and ITS-2 (each <300 bp), can be readily amplified by PCR and sequenced using universal primers, even from DNAs of herbarium specimens. Despite high copy numbers of both spacers, the near uniformity of ITS paralogues, attributed to rapid concerted evolution, allows direct sequencing of pooled PCR products in many species. Divergent paralogues, where detected, require cloning, but may offer a means of obtaining multiple estimates of organismal relationships and of determining placement of the root in a phylogeny independent of outgroup considerations. In reported studies, variation between ITS sequences is mostly attributable to point mutations. A relatively minor proportion of sites is affected by insertions or deletions (indels) among sequences that are similar enough to have retained sufficient signal for phylogenetic analysis. Within these limits, sequence alignment is generally unambiguous except in small regions of apparently lower structural constraint. Phylogenetic analyses of combined data sets from both spacers, where examined, yield trees with greater resolution and internal support than analyses based on either spacer alone. This beneficial effect of simultaneous analysis is not surprising based on the low number of useful characters in each spacer. This effect also suggests high complementarity of spacer data, in accord with similarity in size, sequence variability, and G + C content of ITS-1 and ITS-2 in most investigated groups of closely related angiosperms. Nonindependent evolution of ITS sites involved in intraspacer RNA base-pairing may occur, given possible functional constraints, but preliminary secondary structure analyses of ITS-2 in Calycadenia (Asteraceae) show no definite evidence of compensatory spacer mutations. As expected, levels of ITS sequence variation suitable for phylogenetic analysis are found at various taxonomic levels within families, depending on the lineage. The apparent rates of ITS molecular evolution are roughly correlated with plant life-form, as with chloroplast DNA (cpDNA) data, but reasons for this observation are unclear. ITS characters have improved our understanding of angiosperm phylogeny in several groups by (1) corroborating earlier unexpected findings, (2) resolving conflicts between other data sets, (3) improving resolution of species relationships, or (4) providing direct evidence of reticulate evolution. Hybridization or sorting of ancestral polymorphism in a lineage can complicate interpretation of trees based on any type of evolutionary evidence, including ITS or cpDNA sequences, particularly in the absence of at least one independent phylogenetic data set from the same organisms. The need for phylogenetic markers from the nuclear genome, to complement the rapidly growing body of cpDNA data, makes the ITS region a particularly valuable resource for plant systematists.
A revised and updated classification for the families of flowering plants is provided. Many recent studies have yielded increasingly detailed evidence for the positions of formerly unplaced families, resulting in a number of newly adopted orders, including Amborellales, Berberidopsidales, Bruniales, Buxales, Chloranthales, Escalloniales, Huerteales, Nymphaeales, Paracryphiales, Petrosaviales, Picramniales, Trochodendrales, Vitales and Zygophyllales. A number of previously unplaced genera and families are included here in orders, greatly reducing the number of unplaced taxa; these include Hydatellaceae (Nymphaeales), Haptanthaceae (Buxales), Peridiscaceae (Saxifragales), Huaceae (Oxalidales), Centroplacaceae and Rafflesiaceae (both Malpighiales), Aphloiaceae, Geissolomataceae and Strasburgeriaceae (all Crossosomatales), Picramniaceae (Picramniales), Dipentodontaceae and Gerrardinaceae (both Huerteales), Cytinaceae (Malvales), Balanophoraceae (Santalales), Mitrastemonaceae (Ericales) and Boraginaceae (now at least known to be a member of lamiid clade). Newly segregated families for genera previously understood to be in other APG-recognized families include Petermanniaceae (Liliales), Calophyllaceae (Malpighiales), Capparaceae and Cleomaceae (both Brassicales), Schoepfiaceae (Santalales), Anacampserotaceae, Limeaceae, Lophiocarpaceae, Montiaceae and Talinaceae (all Caryophyllales) and Linderniaceae and Thomandersiaceae (both Lamiales). Use of bracketed families is abandoned because of its unpopularity, and in most cases the broader circumscriptions are retained; these include Amaryllidaceae, Asparagaceace and Xanthorrheaceae (all Asparagales), Passifloraceae (Malpighiales), Primulaceae (Ericales) and several other smaller families. Separate papers in this same volume deal with a new linear order for APG, subfamilial names that can be used for more accurate communication in Amaryllidaceae s.l., Asparagaceace s.l. and Xanthorrheaceae s.l. (all Asparagales) and a formal supraordinal classification for the flowering plants.
Abstract Despite the potential power and extensive use of DNA variation for phylogenctic reconstruction, it has become increasingly apparent that DNA phylogenies are often discordant with organismal phylogenies, Factors responsible for discordance include ...
Although St John’s wort has been subjected to extensive scientific studies in the last decade, there are still many open questions about its pharmacology and mechanism of action. Initial biochemical studies reported that St John’s wort is only a weak inhibitor of monoamine oxidase-A and -B activity but that it inhibits the synaptosomal uptake of serotonin, dopamine and noradrenaline (norepinephrine) with approximately equal affinity. However, other in vitro binding assays carried out using St John’s wort extract demonstrated significant affinity for adenosine, GABAa, GABAb and glutamate receptors. In vivo St John’s wort extract leads to a downregulation of β-adrenergic receptors and an upregulation of serotonin 5-HT2 receptors in the rat frontal cortex and causes changes in neurotransmitter concentrations in brain areas that are implicated in depression. In studies using the rat forced swimming test, an animal model of depression, St John’s wort extracts induced a significant reduction of immobility. In other experimental models of depression, including acute and chronic forms of escape deficit induced by Stressors, St John’s wort extract was shown to protect rats from the consequences of unavoidable stress. Recent neuroendocrine studies suggest that St John’s wort is involved in the regulation of genes that control hypothalamic-pituitary-adrenal axis function. With regard to the antidepressant effects of St John’s wort extract, many of the pharmacological activities appear to be attributable to the naphthodianthrone hypericin, the phloroglucinol derivative hyperforin and several flavonoids. This review integrates new findings of possible mechanisms that may underlie the antidepressant action of St John’s wort and its active constituents with a large body of existing literature.
Computer simulations are useful because they can characterize the expected performance of phylogenetic methods under idealized
conditions. However, simulation studies are also subject to several sources of bias that make the results of different simulation
studies difficult to interpret and often contradictory. In this study, I examined the performance of 26 commonly used methods
of phylogenetic inference for three statistical criteria: consistency, efficiency, and robustness. Methods examined included
parsimony (general, weighted, and transversion), maximum likelihood (assuming Jukes-Cantor and Kimura models of DNA substitution),
and UPGMA, minimum evolution, and weighted and unweighted least squares (with uncorrected, Jukes-Cantor, Kimura, modified
Kimura, and gamma distances). The performance of methods was examined under three models of DNA substitution for four taxa.
The branch lengths of the four-taxon trees were varied extensively in this simulation. The results indicate that most methods
perform well (i.e., estimate the correct tree 2:95% of the time) over a large portion of the four-taxon parameter space. In
general, maximum likelihood performed best, followed by the additive distance methods and the parsimony methods. Lake's method
of invariants and UPGMA are, respectively, inefficient and extremely sensitive to branch-length inequalities. In general,
differential weighting of character-state transformations increases the performance of methods when the weighting can be applied
appropriately. Although methods differ in their consistency, efficiency, and robustness, additional criteria-mainly falsifiability-are
extremely important considerations when choosing a method of phylogenetic inference.
Phylogenetic analysis of nrDNAITS sequence data infers that New Zealand plants previously assigned to Hypericum japonicum are incorrectly placed in that species. Morphological and DNA sequence data support the recognition of two endemic and one indigenous species of Hypericum. Hypericum rubicundulum and H. minutiflorum are newly described species endemic to New Zealand, and the DNA data infer they are sister species. These two species are distinguished from H. pusillum by a rhizomatous growth habit and leaves that are grey‐green to olive‐green and usually ruddy. In comparison to H. rubicundulum, H minutiflorum has a more compact growth habit, much smaller leaves and flowers, and is restricted to the central North Island. Hypericum rubicundulum occurs in inland parts of the South Island, and is known from one collection in the North Island. Hypericum pusillum Choisy is a reinstated name, based on a Tasmanian type, that is applied to prostrate or decumbent, green and sinuate‐leaved plants from Tasmania and New Zealand. This is the m ost common species in New Zealand, occurring on North, South, and Stewart Islands.
Thirty-four taxa representing 12 sections of the genus Hypericum were analyzed along with two representatives of Thornea using nuclear internal transcribed spacer (ITS) sequences in order to assess the scope of phylogenetic relationships in this species-rich genus. The resulting parsimony analysis corroborates the actual classification and interspecific affinities. The molecular data provide support for the monophyletic assemblage of the sections Androsaemum, Hypericum, Olympia, and Drosocarpium and for the polyphyletic origin of Ascyreia, Taeniocarpium, Myriandra, and Adenosepalum. The earlier evolutionary hypotheses concerning the origin of Hypericum balearicum and Hypericum calycinum, and the relatedness of Adenosepalum representatives, are not supported by our data analysis as well as hybrid origin of Hypericum perforatum. The obtained results encourage the use of ITS sequence analysis in resolving the phylogenetic relationships within the member-rich genus Hypericum.
A number of reviews have accompanied and monitored the progress of molecular phylogenetic research on bryophytes, focusing on the publication record itself, bryophyte phylogeny and systematics in the molecular era, as well as the evolution and phylogenetic utility of markers from different genomes. However, none of the recent reviews include a detailed characterization of all molecular markers used in bryophyte phylogenetics. Here we provide an overview of the history and current state of marker utilization, including coding and non-coding sequence markers from all three genomes as well as fingerprinting approaches. The molecular architecture and evolutionary peculiarities, as well as practical aspects such as amplification and sequencing strategies, are outlined for the DNA sequence markers, with a focus on the most commonly employed regions. Their phylogenetic utility and potential for solving some of the remaining, pressing questions in bryophyte phylogeny, as well as their suitability for molecular species identification by DNA barcoding, are discussed.
The chloroplast DNA of 43 species including 16 sections from the genus Hypericum was studied by PCR-RFLP analysis. The PCR-amplified products of four cpDNA regions, trnC-trnD, psbC-trnS, trnL-trnF and rbcL were digested with four restriction endonucleases. A high level of interspecific variation was detected while intraspecific
diversity was not observed. The resulting parsimony analysis indicated the monophyletic assemblage of the sections Androsaemum, Olympia, Drosocarpium and Trigynobrathys. Monophyly of Hypericum is weakly supported, but close relationships of H. perforatum and H. maculatum are indicated. The members of Ascyreia are weakly resolved, but clustering of H. kouytchense and H. oblongifolium is well supported, however, H. reptans is nested with Olympia. CpDNA profiles and the positions on the parsimony tree indicate that the chloroplast donor among the putative parents of
the hybrid species H. ×inodorum is H. androsaemum.
Key words
Hypericum
-cpDNA-PCR-RFLP-phylogeny
The monophyly and evolution of Cynara was investigated using ITS sequence data. Parsimony analysis supports the monophyly of Cynara sensu lato, i.e. including the distinctive taxa C. humilis and C. tournefortii. This contradicts the recent decision to create a new monotypic genus Arcyna for C. tournefortii. A hypothesised close relationship between C. tournefortii and Silybum Adans. is also refuted. Four of the five species of Cynara, for which multiple accessions were sequenced, were shown to be monophyletic but C. baetica was found to be non-monophyletic. Free energy estimates for ITS1 secondary structure and conservation of the 5.8S region suggest that this is not due to the occurrence of pseudogenes. Hybridisation is a plausible explanation but evidence for the likely parents involved in such an event is inconclusive.
Trends concerning coevolution of mode of reproduction and genome size were elucidated by screening both components in 71 species/subspecies of the genus Hypericum. Two independent agamic complexes were identified (sections Ascyreia with ten, and Hypericum with five apomictic species). In the phylogenetically younger section Hypericum, the relative DNA content of apomicts is increased solely by polyploidy. The apomicts of the evolutionarily older section Ascyreia have significantly larger genomes than all other species due to polyploidization and higher DNA content per chromosome. An accumulation of retroelements might be one reason for the larger genomes. The male fertility of the apomicts was reduced compared to sexuals, although all apomicts were facultative pseudogamous, forming reduced male gametes. Another form of apomixis (obligate pseudogamous with unreduced male gametes), probably indicating an escape from interspecific sterility, was found in H. scabrum, the only case of asexual seed formation outside of sections Ascyreia and Hypericum. The described scenario for evolution of apomixis in relation to genome size deserves consideration in harnessing of apomixis.
The genus Hypericum L. (St. John's Wort, Hypericaceae) includes, at the most recent count, 469 species that are either naturally occurring on, or which have been introduced to, every continent in the world, except Antarctica. These species occur as herbs, shrubs, and infrequently trees, and are found in a variety of habitats in temperate regions and in high mountains in the tropics, avoiding only zones of extreme aridity, temperature and/or salinity. Monographic work on the genus has resulted in the recognition and description of 36 taxonomic sections, delineated by specific combinations of morphological characteristics and biogeographic distribution ranges. Hypericum perforatum L. (Common St. John's wort, section Hypericum), one of the best-known members of the genus, is an important medicinal herb of which extracts are taken for their reported activity against mild to moderate depression. Many other species have been incorporated in traditional medicine systems in countries around the world, or are sold as ornamentals. Several classes of interesting bioactive secondary metabolites, including naphthodianthrones (e.g. hypericin and pseudohypericin), flavonol glycosides (e.g. isoquercitrin and hyperoside), biflavonoids (e.g. amentoflavone), phloroglucinol derivatives (e.g. hyperforin and adhyperforin) and xanthones have been identified from members of the genus. A general overview of the taxonomy of the genus and the distribution of relevant secondary metabolites is presented.
Hypericum is a worldwide distributed genus with almost 500 species, including the medically used apomictic species H. perforatum. It is one of the few large plant genera where alpha taxonomy is nearly completed. To conduct a formal cladistic analysis of the genus, we coded 89 morphological characters for all described taxa, and analyzed the data with parsimony and Bayesian methods. The obtained trees indicate Hypericum to be monophyletic, if the monotypic genus Santomasia is included, and Lianthus as the sister group. The arrangement of the remaining genera of Hypericaceae included in the analysis is in congruence with molecular phylogenies. Apomorphic characters supporting the relationships of the genera are pointed out. The cladistic analysis revealed four groups within Hypericum: a basal grade containing Mediterranean species and three big clades containing most of the diversity of the genus. The borders of the Mediterranean Sea as part of the late Tethys Ocean are hypothesized as a probable area of origin for the genus. As indicated in the presented tree, a shrubby habit appears to be the ancestral state within Hypericum from which trees and herbs evolved, and apomixis originated at least three times independently within the genus.
Polyploidization is a major mechanism of speciation in plants. Within the barley genus Hordeum, approximately half of the taxa are polyploids. While for diploid species a good hypothesis of phylogenetic relationships exists, there is little information available for the polyploids (4×, 6×) of Hordeum. Relationships among all 33 diploid and polyploid Hordeum species were analyzed with the low-copy nuclear marker region TOPO6 for 341 Hordeum individuals and eight outgroup species. PCR products were either directly sequenced or cloned and on average 12 clones per individual were included in phylogenetic analyses. In most diploid Hordeum species TOPO6 is probably a single-copy locus. Most sequences found in polyploid individuals phylogenetically cluster together with sequences derived from diploid species and thus allow the identification of parental taxa of polyploids. Four groups of sequences occurring only in polyploid taxa are interpreted as footprints of extinct diploid taxa, which contributed to allopolyploid evolution. Our analysis identifies three key species involved in the evolution of the American polyploids of the genus. (i) All but one of the American tetraploids have a TOPO6 copy originating from the Central Asian diploid H. roshevitzii, the second copy clustering with different American diploid species. (ii) All hexaploid species from the New World have a copy of an extinct close relative of H. californicum and (iii) possess the TOPO6 sequence pattern of tetraploid H. jubatum, each with an additional copy derived from different American diploids. Tetraploid H. bulbosum is an autopolyploid, while the assumed autopolyploid H. brevisubulatum (4×, 6×) was identified as allopolyploid throughout most of its distribution area. The use of a proof-reading DNA polymerase in PCR reduced the proportion of chimerical sequences in polyploids in comparison to Taq polymerase.
The program MRBAYES performs Bayesian inference of
phylogeny using a variant of Markov chain Monte Carlo.
Availability: MRBAYES, including the source code, documentation,
sample data files, and an executable, is available at http://brahms.biology.rochester.edu/software.html.
Contact: johnh{at}brahms.biology.rochester.edu
Hypericum is a worldwide‐distributed genus with almost 500 species, including the medically used, facultative apomictic species H. perforatum. It is one of the few large plant genera for which alpha taxonomy has been completed and most species have been described. To conduct a formal cladistic analysis of the genus, we coded 89 morphological characters for all described taxa and analyzed the data for the species using parsimony and Bayesian methods. The obtained trees indicate that Hypericum is monophyletic if the monotypic genus Santomasia is included, and that Lianthus is its sister. The arrangement of the remaining genera of Hypericaceae included in the analysis is in congruence with molecular phylogenies. Within Hypericum the cladistic analysis revealed a basal grade containing Mediterranean species and three big clades containing most of the diversity of the genus. In contrast to earlier assumptions, we found no indication for an African origin of Hypericum, but assume that the genus evolved in what today is the Mediterranean area. Our phylogenies indicate a shrubby habit to be the ancestral state within Hypericum from which species with tree‐like and herbaceous habit evolved, and that apomixis originated at least three times independently within the genus.
The recently-developed statistical method known as the "bootstrap" can be used to place confidence intervals on phylogenies. It involves resampling points from one's own data, with replacement, to create a series of bootstrap samples of the same size as the original data. Each of these is analyzed, and the variation among the resulting estimates taken to indicate the size of the error involved in making estimates from the original data. In the case of phylogenies, it is argued that the proper method of resampling is to keep all of the original species while sampling characters with replacement, under the assumption that the characters have been independently drawn by the systematist and have evolved independently. Majority-rule consensus trees can be used to construct a phylogeny showing all of the inferred monophyletic groups that occurred in a majority of the bootstrap samples. If a group shows up 95% of the time or more, the evidence for it is taken to be statistically significant. Existing computer programs can be used to analyze different bootstrap samples by using weights on the characters, the weight of a character being how many times it was drawn in bootstrap sampling. When all characters are perfectly compatible, as envisioned by Hennig, bootstrap sampling becomes unnecessary; the bootstrap method would show significant evidence for a group if it is defined by three or more characters.
Part 5(1) of this monographic series of papers on the genus Hypericum contains treatments of Section 10. Olympia and its relatives (Sections 11. Campylopus-16. Crossophyllum), which form a Euro-Mediterranean group centred in southwestern Turkey and extending in area from the Caucasus to Macaronesia, north to Scotland, Denmark and southern Sweden, east to Belarus and the Ukraine and south to north-west Africa and Israel. Section 15. Thasia has been included in Section 16. Crossophyllum. Two new species are described in Section 12. Origanifolium (H. laxiflorum N. Robson, sp. nov. and H. ichelense N. Robson, sp. nov.) and five changes of rank are made; in Section 10. Olympia: H. lycium( N. Robson & Hub.-Mor.) N. Robson, stat. nov. and H. auriculatum (N. Robson & Hub.-Mor.) N.Robson, stat. et nom. nov.; in Section 12. Origanifolia: H. origanifolium var. depilatum (Freyn & Bornm.) N. Robson, stat. nov., H. bourgaei (Boiss.) N. Robson, stat. nov. and H. albiflorum (Hub.-Mor.) N. Robson, stat. nov. In addition, in Section 14. Oligostema, Druce's name for the hybrid H. linariifolium x humifusum has been validated (H. x caesariense Druce ex N. Robson, hybr. nov.); and H. leprosiforme O.Schwartz has been moved from Section 12. Origanifolia to Section 27. Adenosepalum.
Part 5(2) of this monographic series of papers on the genus Hypericum contains treatments of the remaining sections: Sections 17. Hirtella, 18. Taeniocarpium and 19. Coridium, which form a related group centred in eastern Turkey and Transcaucasia and extending in area from Morocco, Portugal and Ireland to western Xinjiang and the Altai and southern Angara-Sayan regions of Siberia. One new series, one new species and one new subspecies are described in Section 17. Hirtella (Series Scabra N.Robson, ser. nov., H. hedgei N.Robson, sp. nov., H. hyssopifolium subsp. acutum N.Robson, subsp. nov.), and two new species and one new subspecies in Section 18. Taeniocarpium (H. pseudorepens N.Robson, sp. nov., H. vaccinioides N.Robson, sp. nov., H. armenum subsp. iranicum N.Robson, subsp. nov.). Four new combinations or changes of rank are made, three in Section 17 (H. elongatum var. lythrifolium (Boiss.) N.Robson, comb. nov., H. elongatum var. racemosum (Kuntze) N.Robson, comb. nov., H. elongatum var. antasiaticum (Grossh.) N.Robson, stat. nov.) and one in Section 18: H. linarioides subsp. alpestre (Steven) N.Robson, stat. et comb. nov.
Hypericum perforatum (St John’s Wort [SJW]) counts among the most favourite herbal drugs, and is the only herbal alternative to classic synthetic antidepressants in the therapy of mild to moderate depression. Several clinical studies have been conducted to verify the effectiveness of ethanolic or methanolic extracts of SJW. Alcoholic SJW extracts are a mixture of substances with widely varying physical and chemical properties and activities. Hyperforin, a phloroglucinol derivative, is the main source of pharmacological effects caused by the consumption of alcoholic extracts of SJW in the therapy of depression. However, several studies indicate that flavone derivatives, e.g. rutin, and also the naphthodianthrones hypericin and pseudohypericin, take part in the antidepressant efficacy. In contrast to the amount of documentation concerning clinical efficacy, oral bioavailability and pharmacokinetic data about the active components are rather scarce. The hyperforin plasma concentration in humans was investigated in a small number of studies. The results of these studies indicate a relevant plasma concentration, comparable with that used in in vitro tests. Furthermore, hyperforin is the only ingredient of H. perforatum that could be determined in the brain of rodents after oral administration of alcoholic extracts. The plasma concentrations of the hypericins were, compared with hyperforin, only one-tenth and, until now, the hypericins could not be found in the brain after oral administration of alcoholic H. perforatum extracts or pure hypericin. Until now, the pharmacokinetic profile of the flavonoids in humans after oral administration of an alcoholic H. perforatum extract has been investigated in only one study. More data are available for rutin and the aglycone quercetin after administration of pure substances or other flavonoid sources.
Chase, M. W. & Hills, H. H.: Silica gel: An ideal material for field preservation of leaf samples for DNA studies. ‐ Taxon 40: 215–220. 1991. ‐ ISSN 0040‐0262.
Silica gels an inexpensive and reliable substance to preserve field‐collected leaves for molecular studies of variation in DNA. A method for its utilization is explained, and results are presented, comparing total cellular DNA samples extracted from a set of fresh and silica‐gel dried samples of the same species, as well as examining the efficiency of endonuclease restriction and intactness of DNA from of a set of field‐collected leaves preserved with silica gel.
— We studied sequence variation in 16S rDNA in 204 individuals from 37 populations of the land snail Candidula unifasciata (Poiret 1801) across the core species range in France, Switzerland, and Germany. Phylogeographic, nested clade, and coalescence analyses were used to elucidate the species evolutionary history. The study revealed the presence of two major evolutionary lineages that evolved in separate refuges in southeast France as result of previous fragmentation during the Pleistocene. Applying a recent extension of the nested clade analysis (Templeton 2001), we inferred that range expansions along river valleys in independent corridors to the north led eventually to a secondary contact zone of the major clades around the Geneva Basin. There is evidence supporting the idea that the formation of the secondary contact zone and the colonization of Germany might be postglacial events. The phylogeographic history inferred for C. unifasciata differs from general biogeographic patterns of postglacial colonization previously identified for other taxa, and it might represent a common model for species with restricted dispersal.
... Pertinent literature published since the first APG classification is included, such that many additional families are now placed in the phylogenetic scheme. ... The placement of the order has varied among the broad phylogenetic analyses conducted to date. ...
Phylogenetic models of the Clusiaceae have so far been based on morphological data only. As an additional source of phylogenetic information, the chloroplast gene rbcL was sequenced for 26 species, representing all available genera of Clusiaceae. The DNA data were analyzed cladistically together with previously published sequences. The results show that the aquatic family Podostemaceae is nested inside Clusiaceae as the sister group of subfamily Hypericoideae or tribe Hypericeae. The subfamilies Kielmeyeroideae and Clusioideae, as delimited in recent morphology-based classifications, are largely supported as monophyletic. The sole exception is Clusiella, which links with Kielmeyeroideae rather than with Clusioideae. We conclude that pollination by resin-collecting bees arose independently in Clusiella and the Clusioideae: Clusieae.
Hypericum species have translucent oil cavities; many species also have superficially similar black internal structures. Contradictory descriptions of both structures emerged from 19th century studies, which we review here. Our study of Hypericum perforation L. leaves and petals shows typical schizogenous translucent oil cavities that develop with a uniseriate epithelium. Black structures, in contrast, are nodules, each composed of several large cells lacking a central intercellular space and surrounded by a biseriate sheath of flattened cells. Nodule cells accumulate black, granular, but non-resinous contents. The ‘streaks’ that traverse petals are elongate tubular cavities or nodules, except for some chimerical tubes composed partly of each. Hypericum balearicum L. leaves have bulging, pustular cavities. A large cellular nodule forms first, by non-synchronous cell divisions within the leaf mesophyll, and is surrounded by a sheath of two to three flattened cell layers. The central cells then separate unevenly to form an irregular cavity into which isolated cells and clusters of cells intrude, some of which continue to divide as other cells degenerate. Little or no oil accumulates in the cavity, and the peripheral lining of cells is very irregular to flattened and empty. Both species studied exhibit secretory structures with previously undescribed anatomical features.
The recently-developed statistical method known as the "bootstrap" can be used to place confidence intervals on phylogenies. It involves resampling points from one's own data, with replacement, to create a series of bootstrap samples of the same size as the original data. Each of these is analyzed, and the variation among the resulting estimates taken to indicate the size of the error involved in making estimates from the original data, In the case of phylogenies, it is argued that the proper method of resampling is to keep all of the original species while sampling characters with replacement, under the assumption that the characters have been independently drawn by the systematist and have evolved independently. Majority-rule consensus trees can be used to construct a phylogeny showing all of the inferred monophyletic groups that occurred in a majority of the bootstrap samples. If a group shows up 95% of the time or more, the evidence for it is taken to be statistically significant. Existing computer programs can be used to analyze different bootstrap samples by using weights on the characters, the weight of a character being how many times it was drawn in bootstrap sampling. When all characters are perfectly compatible, as envisioned by Hennig, bootstrap sampling becomes unnecessary; the bootstrap method would show significant evidence for a group if it is defined by three or more characters.
Part 9 concludes this monographic series of papers on the genus Hypericum. The first chapter contains: (i) extended additions to, revisions of, and comments on the systematic parts (Parts 3–8), including a detailed revision of the larger part of Sect. 3. Ascyreia with a revised key; (ii) shorter additions and corrections to all parts; (iii) a detailed enumeration of the sections of the genus with their perceived interrelationships, and (iv) a revised key to these sections.
In the second chapter, some of the characters treated in Part 2 are reconsidered, but not chemotaxonomy, which is discussed in an appendix contributed by Sara Crockett. The relationships within and between sections of each of the three groups of the genus are then considered, followed by an interpretation of them in terms of distribution, leading to a description of the disjunctions in distribution thereby revealed. This is followed by a discussion.of the various means of dispersal that may have brought about these distribution patterns. In the final section on the evolution of the genus, Santomasia is re-incorporated in Hypericum, but Lianthus and Triadenum continue to be excluded. A consideration of the relationships of the Hypericaceae to the rest of the Clusioid clade leads to a description of the probable characters of the primitive Hypericum.
New taxa and names appearing in this Part are: Sect. 1a: Hypericum sect. Santomasia. Sect. 1: H. smithii. Sect. 3: H. reptans subsp. ogisui; H. rotundifolium; H. oxyphyllum; H. calycinum forma luteum; H. fanjingense; H. hookerianum ‘Rodgersii’; H. lagarocaule. Sect. 5: H. × inodorum ‘Limpsfield’. Sect. 14: H. × caesariense. Sect. 18: H. linarioides Bosse subsp. alpestre. Sect. 28: Hypericum sect. Tripentas. Sect. 29: H. monroi; H. graciliforme; H. marahuacanum subsp. compactum.
Part 4(3) of this monographic series of papers on the genus Hypericum is prefaced by an introduction to the genus and a summary of the aims and methods of the project. This is followed by treatments of the remaining parts of sect. 9. Hypericum sensu stricto and the last segregate section from the original sect. Hypericum, sect. 9b. Graveolentia. Both hitherto untreated parts of the reduced sect. Hypericum are mainly Japanese, but some species extend in distribution as far as Kamchatka, eastern Siberia, central China, and Sabah (Mt. Kinabalu). Sect. Graveolentia is North and Central American. Sect. Hypericum subsect. Hypericum series Senanensia contains seven species from northern Japan and adjacent areas, including H.
pibairense (Miyabe & Y. Kimura) N. Robson, stat. nov., H.
nakaii subsp. miyabei (Y. Kimura) N. Robson, comb. et stat. nov., H.
nakaii subsp. tatewakii (S. Watanabe) N. Robson, comb. et stat. nov. and H.
senanense subsp. mutiloides (R. Keller) N. Robson, comb. et stat. nov. Sect. Hypericum subsect. Erecta contains 23 species and one hybrid from Japan, Korea, central China, Taiwan, Luzon, Sabah and Sumatera, including H.
kawaranum N. Robson, stat. et nom. nov., H.
watanabei N. Robson, stat. et nom. nov., H.
kimurae N. Robson, stat. et nom. nov., H.
pseudoerectum stat. et nom. nov., H.
kitamense (Y. Kimura) N. Robson, stat. nov., H.
kurodakeanum N. Robson, stat. et nom. nov., H.
furusei N. Robson, sp. nov., H.
nuporoense N. Robson, sp. nov. and H.
ovalifolium subsp. hisauchii (Y. Kimura) N. Robson, stat. nov. Sect. Graveolentia contains nine species and one hybrid from southeastern Canada, the eastern half of the United States, Mexico and western Guatemala, including H.
oaxacanum subsp. veracrucense N. Robson, subsp. nov. and H.
macvaughii N. Robson, sp. nov.
Evergreen or sometimes deciduous herbs, shrubs or trees; glands or canals in most parts of the plant; xanthones widespread;
hairs uni- or multicellular, eglandular, colleters common; terminal bud scaly or naked; leaves opposite, occasionally whorled
or alternate, entire, estipulate; in florescences terminal, more or less cymose, rarely axillary or flowers single, flowers
polysymmetric, perfect, usually with prophylls; sepals free, (2-)4-5; petals (3)4-5, free; stamens (9-)∞, freeorvariously
fasciculate or connate, anthers < 1(-1.2)mm long, dithecate, extrose, opening by slits, connective often with glands, staminodes
alternipetalous or 0; nectary absent; ovary superior, 3-5-locular, placentation axile to parietal, ovules 1-∞/carpel, anatropous,
bitegmic, tenuinucellate; stylodia free or basally more or less fused or style single, stigmas more or less expanded, smooth
and sticky or ±punctate and papillate; fruit baccate or capsular, rarely a drupe; seeds small, winged or not, exotegmen lignified,
with sinuous anticlinal walls; embryo straight or rarely curved; endosperm initially nuclear, often absent at maturity; germination
epigeal, phanerocotylar.
As part of our ongoing phylogenetic study of genusHypericum, nuclear ribosomal DNA internal transcribed spacer sequences were analyzed for 36 species ofHypericum as ingroup and two species ofThornea as outgroup. This sampling included most of the previously described species from both Korea and Japan. The ITS phylogeny
suggested that the surveyedHypericum species belong to a monophyletic section,Trigynobrathys, and a polyphyletic section,Hypericum. In addition, two monotypic sections,Sampsonia andRoscyna, were identified. Members of sectionHypericum occur in four different lineages worldwide, which imply at least four independent origins. The Korean and Japanese species
of sectionHypericum form a monophyletic group, except forH. vulcanicum. Instead, that particular species belongs to a distinct monophyletic group withH. scoreri andH. formosa from other geographic areas, and is a sister to sectionTrigynobrathys. The Korean and Japanese species of sectionTrigynobrathys show a monophyletic origin.H. sampsonii is now recognized as a distinct section rather than being a member of sectionsHypericum orDrosocarpium, as had been indicated previously. Our results differ somewhat from those of recent morphological and cytological studies.
The phylogenetic relationships among Korean and Japanese species have now been mostly resolved via ITS phylogeny.
Many species of the paleotropical pioneer tree genus Macaranga Thou. (Euphorbiaceae) live in association with ants. Various types of mutualistic interactions exist, ranging from the attraction of unspecific ant visitors to obligate myrmecophytism. In the latter, nesting space and food bodies are exchanged for protection by highly specific ant partners (mainly species of the myrmicine genus Crematogaster). As a first step toward elucidating the coevolution of ant–plant interactions in the Macaranga–Crematogaster system, we have initiated a molecular investigation of the plant partners' phylogeny. Nuclear ribosomal DNA internal transcribed spacer (ITS) sequences were analyzed for 73 accessions from 47 Macaranga species, representing 17 sections or informally described species groups. Three accessions from the putative sister taxon Mallotus Lour, were included as outgroups. Cladograms of the ITS data revealed Macaranga to be nested within Mallotus. ITS sequences are highly similar within section Pachystemon s.str., suggesting a relatively recent and rapid radiation of obligate myrmecophytes within this section. Forty-three accessions, mainly of ant-inhabited species, were additionally investigated by random amplified polymorphic DNA (RAPD) and microsatellite-primed PCR (MP-PCR) techniques. Phenetic analysis of RAPD and MP-PCR banding profiles generally confirmed the ITS results. Best resolutions for individual clades were obtained when ITS and RAPD/MP-PCR data were combined into a single matrix and analyzed phenetically. The combined analysis suggests multiple (four) rather than a single evolutionary origin of myrmecophytism, at least one reversal from obligate myrmecophytism to nonmyrmecophytism, and one loss of mutualistic specifity.
DNA sequence variation of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA from Arabis holboellii, A. drummondii, and its putative hybrid A. divaricarpa was analyzed to study hybrid speciation in a species system geographically covering nearly the entire North American continent. Based on molecular systematics the investigated species are better combined under the genus Boechera. Multiple intraindividual ITS copies were detected in numerous accessions of A. divaricarpa, and, to a minor extent, in the parental taxa. Comparative phylogenetic analysis demonstrates that reticulate evolution is common. Consequently, concerted evolution of ITS regions resulted in different types of ITS fragments not only in hybrid populations but also in one of the parental taxa, A. holboellii. Hybrid formation often occurred independently at different sites and at different times, which is reflected by ITS copies resampling the original parental sequence variation in different ways. Some biogeographic structuring of genetic diversity is apparent and mirrors postglacial migration routes. Hybridization, reticulation, and apomixis are assumed to be the major forces driving speciation processes in this species complex. Analysis of conserved regions and secondary structures of the ITS region provided no evidence that, in this system, hybrid ITS evolution is predominantly driven in a particular direction. However, two regions in the ITS1 and ITS2, respectively, show higher mutation rates than expected from outgroup comparisons. Strong evidence for the occurrence of apomixis in A. holboellii and A. divaricarpa has come from pollen size measurements and estimations of pollen quality, which favor the hypothesis that A. drummondii served as paternal hybridization partner more frequently than A. holboellii.
