Jun Wen

Smithsonian Institution · Department of Botany

Abstract Transcriptome sequencing or RNA-Seq is one of the most efficient and cost-effective methods currently available for gene discovery in non-model organisms. Recent studies have demonstrated the utility of these data for resolving the relationships of diverse lineages of organisms, by extracting sequences of a large number of single-copy nucl...

Systematic biology is a discipline rooted in collections. These collections play important roles in research and conservation and are integral to our efforts to educate society about biodiversity and conservation. Collections provide an invaluable record of the distribution of organisms throughout the world and through recent and geological time, a...

Studies on chloroplast genomes of ferns and lycophytes are relatively few in comparison with those on seed plants. Although a basic phylogenetic framework of extant ferns is available, relationships among a few key nodes remain unresolved or poorly supported. The primary objective of this study is to explore the phylogenetic utility of large chloro...

Single and low copy nuclear genes offer a larger number of, and more rapidly evolving, characters than the chloroplast and nuclear ribosomal gene sequences that have dominated plant phylogenetic studies to date. Until recently, only one or a few low copy nuclear gene markers were included in such studies. Now, the rapid adoption of “next generation...

Background Coevolution between modern aphids and their primary obligate, bacterial endosymbiont, Buchnera aphidicola, has been previously reported at different classification levels based on molecular phylogenetic analyses. However, the Buchnera genome remains poorly understood within the Rhus gall aphids. Results We assembled the complete genome...

A response is provided to the Rapporteurs’ comments on Proposal 193 to amend the Shenzhen Code . If adopted, Prop. 193 would amend Div. III, Prov. 5 of the Code so as to require a simple majority to approve—as opposed to the current 60% majority to reject (and thus 40% + 1 vote to approve)—General Committee recommendations on conservation, protecti...

The genus Argentina Hill belongs to the tribe Potentilleae Sweet and contains approximately 75 species predominantly distributed in the Sino-Himalayan region and the Malesian archipelago. So far we have less knowledge on the phylogenetic relationships within Argentina owing to limited sampling of Argentina taxa or gene fragments in previous studies...

The world’s diverse and complex climates pose significant challenges in ecological and evolutionary studies, frequently resulting in climatic characterizations that overlook the significance of transitional climates. This study examines the nature and distribution of the transitions between climatic regions worldwide and evaluates their impact for...

Background The suamc genus Rhus (sensu stricto) includes two subgenera, Lobadium (ca. 25 spp.) and Rhus (ca. 10 spp.). Their members, R. glabra and R. typhina (Rosanae: Sapindales: Anacardiaceae), are two economic important species. Chloroplast genome information is of great significance for the study of plant phylogeny and taxonomy. Results The t...

Background Ampelopsideae J. Wen & Z.L. Nie is a small-sized tribe of Vitaceae Juss., including ca. 47 species from four genera showing a disjunct distribution worldwide across all the continents except Antarctica. There are numerous species from the tribe that are commonly used as medicinal plants with immune-modulating, antimicrobial, and anti-hyp...

Nekemias is a perennial woody vine with nine species that had been originally placed in Ampelopsis. These species of Nekemias are economically and medically important. Limited information is available on the genomic characteristics of the chloroplasts of this genus. Nekemias hypoglauca (Hance) J. Wen & Z. L. Nie 2014 contains 131 unique genes (86 p...

The angiosperm family Cactaceae, a member of the Caryophyllales, is a large and diverse group of stem succulents comprising 1438-1870 species within approximately 130 genera predominantly distributed from northern Canada to Patagonia. Four centers of diversity from Central and North America (Chihuahua, Puebla-Oaxaca, Sonora-Sinaloan, and Jalisco) a...

The small subfamily Linnaeoideae of Caprifoliaceae exhibits a disjunct distribution in Eurasia and North America, including Mexico, with most taxa occurring in eastern Asia or Mexico and the monospecific Linnaea Gronov. ex L. having a circumboreal to north temperate distribution. We sampled 17 of the 20 species representing all Linnaeoideae genera...

Background Convallarioideae is a subfamily of Asparagaceae, a morphologically diverse group comprising 7 tribes (i.e., Eriospermeae, Rusceae, Dracaeneae, Nolineae, Convallarieae, Ophiopogoneae, and Polygonateae) and two unclassified genera. Methods and Results In this study, we conducted comparative chloroplast genomic and phylogenetic analyses on...

The discontinuous geographic distribution pattern of plants in the north temperate zone has been a focus of biogeographic research, especially concerning the mechanisms behind the formation of such a pattern and the spatial and temporal evolution of this intermittent distribution pattern. Hypotheses of boreotropical origin, land bridge migration, a...

Background Explaining contrasting patterns of distribution between related species is crucial for understanding the dynamics of biodiversity. Despite instances where hybridization and whole genome duplication (WGD) can yield detrimental outcomes, a role in facilitating the expansion of distribution range has been proposed. The Vitaceae genus Causon...

We herein describe a new species, Panax siamensis J. Wen, from the tropical monsoon forests in northern Thailand. Panax siamensis is characterized by a combination of characters including horizontally elongated rhizomes with thick internodes, 3–5 whorled leaves each with 7–9 sessile and lanceolate leaflets, lanceolate bracteoles not persisting at t...

Hainan Island has the most extensive and well‐preserved tropical forests in China. With rapid economic development of Hainan, biodiversity is increasingly at risk. Determining the spatial patterns of plant diversity in Hainan and explaining the drivers behind plant diversity are important considerations in assessing and maximizing the effectiveness...

The evolutionary histories of species have been shaped by genomic, environmental, and morphological variation. Understanding the interactions among these sources of variation is critical to infer accurately the biogeographic history of lineages. Here, using the geographically widely distributed plum genus (Prunus, Rosaceae) as a model, we investiga...

Systematics has experienced major recent developments in biodiversity informatics and genomics. Digitization efforts and developments in biodiversity informatics are allowing the systematics community to explore ways to discover new species and new sets of characters for taxonomy via machine learning. Large-scale genomic information has been increa...

Steroidal saponins are a class of specialized metabolites essential for plant's response to biotic and abiotic stresses. They are also important raw materials for the industrial production of steroid drugs. Steroidal saponins are present in some monocots, such as Dioscorea and Paris, but their distribution, origin, and evolution in plants remain po...

Cyphostemma , with ca. 200 species, is the second‐largest genus after Cissus in the grape family Vitaceae. Cyphostemma exhibits a high degree of morphological variation both between and within species that confounds species delimitation. Additional questions remain due to limited taxon sampling, original reference specimens damaged or lost and inco...

Premise: The preservation of plant tissues in ethanol is conventionally viewed as problematic. Here, we show that leaf preservation in ethanol combined with proteinase digestion can provide high-quality DNA extracts. Additionally, as a pretreatment, ethanol can facilitate DNA extraction for recalcitrant samples. Methods: DNA was isolated from le...

A set of newly designed Vitaceae baits targeting 1013 genes was employed to explore phylogenetic relationships among North American Vitis. Eurasian Vitis taxa including Vitis vinifera were found to be nested within North American Vitis subgenus Vitis. North American Vitis subgenus Vitis can be placed into nine main groups: the Monticola group, the...

The genus Lonicera L. is widely distributed in the north temperate zone and is well-known for its high species richness and morphological diversity. Previous studies have suggested that many sections of Lonicera are not monophyletic and phylogenetic relationships within the genus are still poorly resolved. In this study, we sampled 37 accessions of...

Prunus is an economically important genus widely distributed in the temperate Northern Hemisphere. Previous studies on the genus using a variety of loci yielded conflicting phylogenetic hypotheses. Here, we generated nuclear reduced representation sequencing data and plastid genomes for 36 Prunus individuals and two outgroups. Both nuclear and plas...

The north temperate region was characterized by a warm climate and a rich thermophilic flora before the Eocene, but early diversifications of the temperate biome under global climate change and biome shift remain uncertain. Moreover, it is becoming clear that hybridization/introgression is an important driving force of speciation in plant diversity...

Genome-scale data have significantly increased the number of informative characters for phylogenetic analyses and recent studies have also revealed widespread phylogenomic discordance in many plant lineages. Aralia sect. Aralia is a small plant lineage (14 spp.) of the ginseng family Araliaceae with a disjunct distribution between eastern Asia (11...

Hybridization caused by frequent environmental changes can lead both to species diversification (speciation) and to speciation reversal (despeciation), but the latter has rarely been demonstrated. Parthenocissus, a genus with its trifoliolate lineage in the Himalayan–Hengduan Mountains (HHM) region showing perplexing phylogenetic relationships, pro...

The sumac Rhus chinensis Mill. is an economically and ecologically important shrub or tree species in the family of Anacardiaceae with a wide distribution in East to Southeast Asia. We assembled the complete chloroplast genome of 159,187 bp in length and the GC content of 37.8%. The genome encoded 132 genes, including 86 protein-coding genes, 37 tR...

Although the vast majority of Prunus L. (Rosaceae) species have clearly differentiated sepals and petals, two former genera Maddenia and Pygeum have been described as having an undifferentiated perianth. However, floral morphological and morphogenetic data are scarce, and a renewed investigation is essential to understand the evolution of the peria...

East Asian wild grapes show a high level of species diversity and have been widely recognized as important germplasm resources of wine, table grapes and resistance to biotic and abiotic stresses for the grape industry. However, the deeper phylogenetic relationships and drivers of diversification of East Asian Vitis remain poorly understood. Hybridi...

Cissus is the largest genus in Vitaceae and is mainly distributed in the tropics and subtropics. Crassulacean acid metabolism (CAM), a photosynthetic adaptation for the occurrence of succulent leaves or stems, indicates that convergent evolution occurred in response to drought stress during species radiation. Here, we provided the chromosomal level...

Premise: There has been a great increase in using climatic data in phylogenetic studies over the past decades. However, compiling the high-quality spatial data needed to perform accurate climatic reconstructions is time-consuming and can result in poor geographical coverage. Therefore, researchers often resort to qualitative approximations. Our ai...

The genus Lonicera L. is widely distributed and is well-known for its high species richness and morphological diversity. Previous studies have suggested that many sections of Lonicera are not monophyletic and phylogenetic relationships within the genus are still poorly known. In this study, we sampled 37 accessions of Lonicera, covering four sectio...

Diosgenin saponins isolated from Dioscorea species such as Dioscorea zingiberensis exhibit a broad spectrum of pharmacological activities. Diosgenin, the aglycone of diosgenin saponins, is an important starting material for production of steroidal drugs. However, how plants produce diosgenin saponins, and the origin and evolution of diosgenin sapon...

Cissus is the largest genus in Vitaceae and is mainly distributed in the tropics and subtropics. Crassulacean acid metabolism (CAM), a photosynthetic adaptation for the occurrence of succulent leaves or stems, indicates that convergent evolution occurred in response to drought stress during species radiation. Here, we provided the chromosomal level...

The liquorice tribe Glycyrrhizeae is a leguminous herbaceous group of plants comprised of the genera Glycyrrhiza and Glycyrrhizopsis. Some Glycyrrhiza taxa contain glycyrrhizin, a pharmacologically significant sweet substance that also has applications in crafting industrial materials. Here, we utilized an expanded taxon sampling of Glycyrrhizeae t...

The phenomenal advances in sequencing techniques and analytical development during the last decade have provided a unique opportunity to unravel the evolutionary history of lineages under complex patterns of evolution. This is the case of the largest clade of the ginseng family (Araliaceae), the Asian Palmate group (AsPG), where the large internal...

The utility of transcriptome data in plant phylogenetics has gained popularity in recent years. However, because RNA degrades much more easily than DNA, the logistics of obtaining fresh tissues has become a major limiting factor for widely applying this method. Here, we used Ranunculaceae to test whether silica-dried plant tissues could be used for...

Phylogenomic evidence from an increasing number of studies has demonstrated that different data sets and analytical approaches often reconstruct strongly supported but conflicting relationships. In this study, 785 single‐copy nuclear genes and 75 complete plastomes were used to infer the phylogenetic relationships and estimate the historical biogeo...

Background: Deep-branching phylogenetic relationships are often difcult to resolve because phylogenetic signals are obscured by the long history and complexity of evolutionary processes, such as ancient introgression/hybridiza�tion, polyploidization, and incomplete lineage sorting (ILS). Phylogenomics has been efective in providing informa�tion for...

Rhus gall aphids (Hemiptera: Aphididae: Eriosomatinae) stimulate the formation of galls on their primary host plants (sumacs: Rhus spp., Anacardiaceae). The shapes of galls are often used as an extended phenotype to identify the aphid species and subspecies. We collected four Rhus galls with conspicuously different shapes formed by Kaburagia rhusic...

Plant biologists have debated the evolutionary origin of the apple tribe (Maleae; Rosaceae) for over a century. The “wide-hybridization hypothesis” posits that the pome-bearing members of Maleae (base chromosome number x = 17) resulted from a hybridization and/or allopolyploid event between progenitors of other tribes in the subfamily Amygdaloideae...

Premise: DNA-based species identification is critical when morphological identification is restricted, but DNA-based identification pipelines typically rely on the ability to compare homologous sequence data across species. Because many clades lack robust genomic resources, we present here a bioinformatics pipeline capable of generating genome-wid...

Chimonanthus of Calycanthaceae is a small endemic genus in China, with unusual winter-blooming sweet flowers widely cultivated for ornamentals and medicinal uses. The evolution of Chimonanthus plastomes and its phylogenetic relationships remain unresolved due to limited availability of genetic resources. Here, we report fully assembled and annotate...

Background and Aims Abelia (Caprifoliaceae) is a small genus with five species, including one artificial hybrid and several natural hybrids. The genus has a discontinuous distribution in Mainland China, Taiwan Island and the Ryukyu Islands, providing a model system to explore the mechanisms of species dispersal in the East Asian flora. However, the...

The Adiantum pedatum complex is disjunctly distributed in North America and eastern Asia. In this study, we carried out a detailed morphological study based on 137 specimens representing the biogeographic diversity of this complex. The sequences of eight chloroplast markers of 35 samples were analyzed with maximum likelihood and Bayesian inference....

Vitis shizishanensis (Vitaceae), a new species from Hubei, China, is described and illustrated. It is morphologically similar to V. flexuosa and V. bryoniifolia , but differs in leaf lobing and pubescence. It can be easily distinguished from the two species based on its glabrous or with very sparse arachnoid tomentum on the abaxial mature leaf surf...

Understanding biological diversity and the mechanisms of the Sino-Japanese disjunctions are major challenges in eastern Asia biogeography. The Sino-Japanese flora has been broadly studied as an ideal model for plant phylogeography. Diabelia (Caprifoliaceae) is an East Asian genus, with a disjunctive distribution across the Sino-Japanese region. How...

PREMISE The use of climatic data on phylogenetic studies has greatly increased in the last decades. High-quality spatial data and accurate climatic information are essential to minimize errors in the climatic reconstructions to the past. However, despite the huge amount of already available biodiversity digital information, the process of compiling...

Phylogenomic evidence from an increasing number of studies has demonstrated that different data sets and analytical approaches often reconstruct strongly supported but conflicting relationships. In this study, hundreds of single-copy nuclear (SCN) genes (785) and complete plastomes (75) were used to infer the phylogenetic relationships and estimate...

The recognition, identification, and differentiation of closely related plant species present significant and notorious challenges to taxonomists. The Maddenia group of Prunus, which comprises four to seven species, is an example of a group in which species delimitation and phylogenetic reconstruction have been difficult, due to the lack of clear m...

Causonis (Vitaceae) is widely distributed in the tropical, sub-tropical and temperate regions from Asia to Australia. The genus was established by Rafinesque in 1830 but included under Cayratia by Gagnepain in 1911. Generic status of Causonis was restored in 2013, but circumscription of the genus and its species remained poorly understood. Here, we...

The CYP75 gene family plays an important role in flavonoid biosynthesis in plants. Little is known about the evolution of the gene family within the grape family. Here, we extracted the CYP75 genes from transcriptome data of 15 grape species and 36 representative genomes from other plants to explore the evolutionary history of the CYP75 gene family...

Within the legume family, the taxonomic status of subtribe Glycyrrhizinae of tribe Galegeae and of the genus Adinobotrys has been re-assessed. Based on genome skimming data, we conducted phylogenomic analyses of the inverted repeat-lacking clade within subfamily Papilionoideae. The results support the sister relationship between Glycyrrhizeae and A...

Cyphostemma calcarium Rabarij & L.M.Lu, sp. nov., is herein described as a new species found on limestone outcrops in northern Madagascar. Its diagnostic morphological characteristics were compared to the species occurring in the Ankarana Special Reserve. We present detailed descriptions, illustrations, distribution map, and a preliminary conservat...

The utility of transcriptome data in plant phylogenetics has gained popularity in recent years. However, because RNA degrades much more easily than DNA, the logistics of obtaining fresh tissues has become a major limiting factor for widely applying this method. Here, we used Ranunculaceae to test whether silica-dried plant tissues could be used for...

Background and aims Zanthoxylum L. is the only pantropical genus within Rutaceae, with a few species native to temperate eastern Asia and North America. Efforts using Sanger sequencing failed to resolve the backbone phylogeny of Zanthoxylum. In this study, we employed target enrichment high-throughput sequencing to improve resolution. Gene trees we...

With the decreasing cost and availability of many newly developed bioinformatics pipelines, next-generation sequencing (NGS) has revolutionized plant systematics in recent years. Genome skimming has been widely used to obtain high-copy fractions of the genomes, including plastomes, mitochondrial DNA (mtDNA), and nuclear ribosomal DNA (nrDNA). In th...

Convergent evolution, often viewed as the inevitable outcome of natural selection, has received special attention since the time of Darwin. Clematis is well known for its climbing habit, but it has some shrubby species, known as sect. Fruticella s.l. The shrubby Clematis species are distributed in the dry habitats of Central Asia and adjacent areas...

Biodiversity exchanges across the Malesian region, linking the distinct biotas of Asia and Australia, have long attracted the curiosity of biologists. Tetrastigma (Vitaceae) has a wide distribution in Asia through the Sunda archipelago to Australia and provides a good case to elucidate floristic exchange between Asia and Australia. Tetrastigma spec...

This paper presents a taxonomic study of genus Vincetoxicum s.str. from southern Asia. Eleven regional endemic species are recognized on the basis of herbarium studies and fieldwork. Three new species are described: V. lenifolium sp. nov. (endemic to Pakistan), V. stewartianum sp. nov. (endemic to India), and V. subcanescens sp. nov. (endemic to Pa...

This study reports the recognition of Vitis adenoclada Hand.-Mazz. from southern China. The species was not recognized in the Flora Reipublicae Ropularis Sinicicae and Flora of China treatments. Recent field studies and examination of herbarium collections including the type material suggest that Vitis adenoclada is morphologically similar to V. he...

Disjunctive distribution patterns and drivers of the Sino-Japanese flora in East Asia have attracted much attention in the past decades, which is also served as an important glacial sanctuary during the quaternary glacial period. However, few studies have focused on the phylogeography, diversification and evolution of morphological character at the...

Chamaerhodos is a small genus with ca 7–8 species with a disjunct distribution in Asia and western North America. Due to limited sampling of species and genes in previous studies, little is known about the phylogenetic relationships among the species. Moreover, chloroplast genomic resources for Chamaerhodos have been limited. Herein, we conducted a...

The olive genus Olea includes c. 30-40 taxa in three subgenera (Olea, Tetrapilus, and Paniculatae) within the family Oleaceae. Historically, the Olea genus was classified into four groups that were overall well supported by reconstructed phylogenies, despite incomplete sampling of subgenus Tetrapilus and poor resolution within clades. These analyse...

The inverted repeat-lacking clade (IRLC) is one of the most derived clades within the subfamily Papilionoideae of the legume family, and includes various economically important plants, e.g., chickpeas, peas, liquorice, and the largest genus of angiosperms, Astragalus. Tribe Wisterieae is one of the earliest diverged groups of the IRLC, and its gene...

Cyphostemma calcarium is herein described as a new species on the limestone outcrops in northern Madagascar. Its diagnostic morphological characteristics were compared to the species occurring in Ankarana Special Reserve. We present detailed descriptions, illustrations, distribution map, and a preliminary conservation assessment of the species. An...

Zanthoxylum is a genus of woody plants in the Rutaceae family distributed pantropically, with some species extending to temperate regions in East Asia and North America. Here, we present the complete chloroplast genome sequences of four species, two of them critically endangered, endemic to tropical islands.

The tribe Senecioneae is one of the largest tribes in Asteraceae, with a nearly cosmopolitan distribution. Despite great efforts devoted to elucidate the evolution of Senecioneae, many questions still remain concerning the systematics of this group, from the tribal circumscription and position to species relationships in many genera. The hybridizat...

Comprising about 82% of the extant fern species diversity, Polypodiales are generally believed to have diversified in the Late Cretaceous. We estimated the divergence times of Polypodiales using both penalized likelihood and Bayesian methods, based on a dataset consisting of 208 plastomes representing all 28 families and 14 fossil constraints refle...

Background and Aims Abelia (Caprifoliaceae) is a small genus with five species (including one artificial hybrid). The genus has a disjunct distribution across mainland China, Taiwan and the Ryukyu Islands, providing a model system to explore species dispersal mechanisms of the East Asian flora. However, the current phylogenetic relationships within...