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Chromosome counts/DNA ploidy level (DNA-PL) and modes of reproduction of the following species, hybridogenous species and hybrids of Pilosella from the Krkonoše Mts (Czech Republic) are reported: P. aurantiaca (2n = 36,2n = 45, DNA-PL tetraploid, pentaploid, all apomictic); P. bauhini subsp. bauhini (2n = 45, with a long hemizygous marker chromosom...
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Context 1
... cytotype of P. aurantiaca. The second is that of a reduced female gamete of a hexaploid cytotype of P. rubra with an unreduced male gamete of tetraploid cytotype of P. aurantiaca (cf. Krahulec et al. 2004). Because it has a rather high density of stellate hairs on the under surface of its leaves and a deeply branched stem (Electronic Appendix 1: Fig. 4) we consider that the second alternative is the most likely (P. rubra is a stabilized hybridogenous type including P. officinarum and for this reason it has many stellate hairs on the under surface of its leaves). No pentaploid cytotype of P. aurantiaca or P. rubra was found by us at this locality or in the surrounding ...
Context 2
... P. blyttiana (Fr.) F. W. Schultz et Sch. Bip., Hieracium fuscum Vill.] In the complex of wet meadows at Mokré jámy by Pomezní Boudy we found a type morphologically close to P. aurantiaca, which corresponds to P. fusca: some of the rosette leaves are acute, with few stellate hairs; involucral bracts densely hairy; inflorescence with many capitula (Fig. 4). It has dark green and rigid leaves. Because this is the richest locality for P. blyttiana we think it is a hybrid of these two species (in fact, the product of backcrossing P. blyttiana with one of its parents, P. aurantiaca). There are no plants corresponding to P. fusca in the Czech Republic (Chrtek 2004, Zahn 1922-1930. This ...
Citations
... The genus Pilosella provides a good example. Both sexual and apomictic biotypes are commonly found in close proximity, and they are known to readily hybridize in natural habitats (Krahulcováand Krahulec, 1999;Houliston and Chapman, 2001;Krahulcováet al., 2001;Fehrer et al., 2007;Mraź et al., 2009). Also, apomixis in this genus is facultative, with progeny forming from both sexual and asexual developmental pathways on the same plant, and occasionally from a combination of both Bicknell et al. (2003). ...
Pilosella piloselloides var. praealta (syn. P. praealta; Hieracium praealtum) is a versatile model used to study gametophytic apomixis. In this system apomixis is controlled by three loci: one that controls the avoidance of meiosis (LOA), one that controls the avoidance of fertilization (LOP) and a third that controls autonomous endosperm formation (AutE). Using a unique polyhaploid mapping approach the LOP locus was mapped to a 654 kb genomic interval syntenic to linkage group 8 of Lactuca sativa. Polyhaploids form through the gametophytic action of a dominant determinant at LOP, so the mapped region represents both a functional and a physical domain for LOP in P. piloselloides. Allele sequence divergence (ASD) analysis of the PARTHENOGENESIS (PAR) gene within the LOP locus revealed that dominant PAR alleles in Pilosella remain highly similar across the genus, whilst the recessive alleles are more divergent. A previous report noted that dominant PAR alleles in both Pilosella and Taraxacum are modified by the presence of a class II transposable element (TE) in the promoter of the gene. This observation was confirmed and further extended to the related genus Hieracium. Sufficient differences were noted in the structure and location of the TE elements to conclude that TE insertional events had occurred independently in the three genera. Measures of allele crossover amongst the polyhaploids revealed that P. piloselloides is an autopolyploid species with tetrasomic inheritance. It was also noted that the dominant determinant of LOP in P. piloselloides could transmit via a diploid gamete (pollen or egg) but not via a haploid gamete. Using this information, a model is presented of how gametophytic apomixis may have evolved in several members of the Lactuceae, a tribe of the Asteraceae.
... Pilosella aurantiaca je u nás zastoupena tetraploidními rostlinami, které rostou kromě hor i v nižších polohách, kde mají často invazní chování. Kromě toho byl ve vyšších polohách Šumavy, Krkonoš a Hrubého Jeseníku nalezen pentaploidní cytotyp, který je možné morfologicky odlišit od tetraploida (Krahulcová et al. 2013). ...
... Nažky jsou šířeny především větrem, ale na delší vzdálenosti i automobilovou dopravou, jak tomu nasvědčuje např. výskyt teplomilného druhu P. rothiana v Krkonoších na parkovišti v Modrém dole v nadmořské výšce těsně nad 1000 m (Krahulcová et al. 2013). ...
... glomerata), který se evidentně kříží s oběma těmito rodičovskými taxony a vytváří hybridní roj, který původní rodičovské taxony spojuje; je pak často obtížné rozhodnout, co jsou rodiče a co hybridy . V Krkonoších je však hybridogenní druh P. scandinavica vzácný (Krahulcová et al. 2013). Podobně byl na Šumavě nalezen hybrid mezi P. aurantiaca a P. fl oribunda ). ...
This paper summarises the principal factors underlying the variation of Pilosella populations in the fi eld:
1. Variation of taxa (basic, and hybridogenous species, recent hybrids); 2. Variation in chromosome number;
3. Variation in breeding systems; 4. Hybridization; 5. Population structure. Suggestions on how to
study Pilosella populations are given.
... (Bräutigam 2017). The tetraploid P. fusca was found in the Krkonoše Mts., the Czech Republic (Krahulcová et al. 2013), similarly to the tetraploid apomictic P. blyttiana (Krahulcová et al. 2001). The ploidy level in the wild hybrids of P. lactucella and P. aurantiaca has also been reported from other countries in Central Europe, namely, from Poland (tetraploid and hexaploid hybrids, Skalińska 1967), Germany (triploid P. blyttiana, both the tetraploid and pentaploid P. fusca, Paule et al. 2017) and Austria (triploid P. blyttiana, Schuhwerk & Lippert 2002). ...
2020): Ploidy level and breeding system in some populations of Pilosella (Asteraceae) in eastern and southern Slovakia.-Thaiszia-J. Bot. 30 (1): 037-058. Abstract: The ploidy level/breeding system was determined in following species and hybrids originating from populations of the agamic polyploid complex of Pilosella in Slovakia: P. bauhini (either sexual tetraploids or apomictic pentaploids), P. hoppeana subsp. testimonialis, P. lactucella, P. onegensis (all three taxa diploid and so supposedly sexual), P. officinarum (pentaploids, hexaploids and octoploids, all cytotypes apomictic), P. glomerata (one pentaploid, another plant hexaploid and apomictic), P. macrostolona (apomictic hexaploids), P. schultesii, (mostly tetraploid, one plant an apomictic pentaploid), P. lactucella × P. onegensis (diploid and sexual), P. lactucella × P. aurantiaca (triploid and apomictic) and P. bauhini × P. officinarum (both sexual and apomictic tetraploids, apomictic pentaploids and apomictic hexaploids). The paper provides two karyological novelties in Pilosella: (a) A new hexaploid cytotype was revealed in Pilosella glomerata; (b) The octoploid apomictic and monoclonal plants of Pilosella officinarum were grown from seeds suggesting an occurrence of fruiting octoploid maternal plant(s). Such a cytotype would represent a new highest ploidy level detected in P. officinarum in the field. The cytotypes that were attributed both to P. officinarum and to the hybrids of P. bauhini and P. officinarum differed in a within-population clonal diversity. This effect could result from a different impact of (residual) sexuality and/or a different rate of origin of particular hybrid cytotypes. All findings presented in the paper are compared with published data on Pilosella species that refer preferentially to Slovakia, but also to a broader area in Central Europe.
... The number of chromosomes in root-tip meristems of pot-grown plants were counted. The squashed meristems were stained with lacto-propionic orcein (Dyer 1963); for a detailed description of the procedure, see Krahulcová & Krahulec (1999). ...
... The method used for determining the mode of reproduction of individual plants is given in Electronic Appendix 1. The mode of reproduction was confirmed for most plants during cultivation, based on the presence of well-developed (filled) seed in open-pollinated versus emasculated (cut) capitula (Gadella 1984, Krahulcová & Krahulec 1999). This method detects parthenogenetic seed development and is routinely used for autonomous apomictic Asteraceae (Richards 1986). ...
... In the absence of FCSS, the seed formed by either open pollinated of hand-pollinated capitula were sown on wet filter paper in Petri dishes. The seed was left to germinate and root-tip meristems stained with lacto-propionic orcein were used for chromosome counts (Krahulcová & Krahulec 1999). Comparing the chromosome number/karyotype of the maternal plant with that of the respective seed-progenies, we inferred either apomictic/ polyhaploid progeny (maternal/polyhaploid karyotypes in the progeny), or sexual progeny (diverse karyotypes in the progeny, which must have originated from sexual mating). ...
Populations of Pilosella species in ruderal habitats in the city of Prague: consequences of the spread of P. aurantiaca and P. rothiana Populace druhů rodu Pilosella na ruderálních stanovištích v Praze: následky expanze P. aurantiaca a P. rothiana Populations of Pilosella species in ruderal habitats in the city of Prague: consequences of the spread of P. aurantiaca and P. rothiana.-Preslia 92: 167-190. Consequences of Pilosella aurantiaca and P. rothiana (stabilized hybridogenous species P. echioi-des > P. officinarum) spreading into three semi-ruderal localities in the city of Prague were studied. Numbers of chromosomes / DNA ploidy level and mode of reproduction are given for all the species and hybrids studied. Both P. aurantiaca and P. rothiana are apomictic and tetraploid with 2n = 4x = 36. Pilosella rothiana hybridizes with pentaploid P. piloselloides (P. ×heterodoxa, 2n = 6x = 53/54) and tetraploid P. officinarum (P. ×bifurca, 2n = 6x = 54). Pilosella aurantiaca hybrid-izes with tetraploid P. caespitosa (P. ×fuscoatra, 2n = 4x = 36), P. piloselloides (P. ×derubella, 2n = 5x = 45), P. officinarum (P. ×rubra, 2n = 6x) P. rothiana (2n = 6x = 54), P. ×bifurca (with 2n = 5x = 45) and P. visianii (tetraploid, 2n = 4x = 36). Hybrids of P. aurantiaca with tetraploid P. ×lepto-phyton were of two types, the tetraploid hybrid originating from parental reduced gametes and the hexaploid hybrid originating from a reduced and an unreduced parental gamete, respectively. Introgression from apomictic P. bauhini towards sexual P. officinarum was found in a hybrid swarm in one of the populations studied. Evolutionary potential of recent hybrids was evaluated with respect to their mode of reproduction; most of the recent hybrids were not apomictic. It seems impossible to predict the mode of reproduction from that of the parental species.
... A complex study of the structure of species-mixed populations supplemented by evaluation of seed progenies revealed features that are commonly shared by hybridizing sexual-apomictic populations of Pilosella in the Czech Republic and Germany Krahulcová & al. 2009aKrahulcová & al. , 2012Krahulcová & al. , 2013Rosenbaumová & Krahulec 2015). Due to residual sexuality, facultatively apomictic plants play an important role as maternal parents in shaping the structure of these populations. ...
... The only new data in this study refer to seed progenies generated in the field and to crossing experiments. According to a population-based approach that was used for studies in the species-mixed Pilosella populations in the Czech Republic and Germany Krahulcová & al. 2009aKrahulcová & al. , 2012Krahulcová & al. , 2013Rosenbaumová & Krahulec 2015), we compared the relevant processes at population level in two distant parts of the distribution area in Europe (Fig. 1). We analysed the populations encompassing the mature plants from the field and their progeny arrays in both regions. ...
The species-mixed Pilosella populations comprising diploid sexual and polyploid facultatively apomictic biotypes were studied in Bulgaria. Parentage of co-occurring recent hybrids was inferred from a combination of morphology and ploidy level that corresponded to simple/multiple crosses of basic species via either reduced or unreduced gametes. The flow cytometric seed screening illustrated the capacity for heteroploid hybridization both in open-pollinated plants in the mixed-ploidy populations and in crossing experiments. The diploid sexual species in Bulgaria have a limited impact on interspecific hybridization, and simple inter-cytotype hybrids are only sporadically formed. The origin of the most common hybrids in Bulgaria that are apomictic and retain the pentaploid/hexaploid ploidy level of a co-occurring putative apomictic parent remains unclear. The absence of stabilized hybridogeneous species and scarcity of commonly hybridizing polyploid sexual biotypes are crucial attributes that distinguish the Pilosella populations in Bulgaria from those in the Czech Republic and Germany. No recent high-polyploid hybrids of 2n + n origin that would potentially become drivers of ongoing hybridization in the mixed sexual-Apomictic Pilosella populations similar to those in Central Europe have been recorded in Bulgaria. The pattern of co-occurring cytotypes in Bulgaria likely limits interspecific hybridization due to stronger ploidy barriers.
... Poměrně dobře je prozkoumáno především území Krkonoš, kde má výzkum už více než 140 letou tradici (cf. Nägeli & Peter 1885, Schneider 1888-1895, Zahn 1922-1930, Krahulcová & Krahulec 1999, avšak i zde lze očekávat řadu nových a překvapivých nálezů. Z ostatních částí východních Čech jsou známy spíše jednotlivé a převážně historické údaje. ...
Finds of 18 species of the genus Pilosella from the Dolní Poorličí area are published. Five basic species (Pilosella aurantiaca, P. bauhini, P. caespitosa, P. officinarum, P. piloselloides) and 13 hybridogenous species (hybrid P. bauhini × P. glomerata, P. brachiata, P. floribunda, P. glomerata, P. heterodoxa, P. iserana, P. macranthela, P. macrostolona, P. piloselliflora, P. polymastix, P. rothiana, P. stoloniflora and P. visianii) were found in the studied area. Thirteen taxa are new to Phytogeographic District 61 Dolní Poorličí. Most species were found at localities with vegetation in early successional stages. These were mostly pastures, markedly sparsely vegetated and regularly mowed relatively dry meadows, edges of forest trails, ruderal areas, surroundings of railway stations and sandpits, where vegetation disturbances and other types of disturbances regularly occur. Pilosella heterodoxa, P. macranthela and P. polymastix are the most significant finds in the studied area. Recently created hybrid swarms between the species P. fl oribunda and P. offi cinarum, and P. caespitosa and P. officinarum have also been found at a number of localities. These hybrid swarms were morphologically different from stabilized hybridogenous species of the known combinations. Morphotypes in these hybrid swarms could not be identified reliably.
... The root tip meristems stained by lacto-propionic orcein were used for mitotic chromosome counts (Krahulcová & Krahulec, 1999). If not otherwise stated, the chromosomes were counted in cultivated mature plants sourced from the field, and the herbarium specimens correspond to respective plants analysed. ...
... The root tip meristems stained by lacto-propionic orcein were used for mitotic chromosome counts (Krahulcová & Krahulec, 1999). If not otherwise stated, the chromosomes were counted in cultivated mature plants sourced from the field, and the herbarium specimens correspond to respective plants analysed. ...
... Hieracium pilosella L. (Asteraceae) is a hermaphroditic, stoloniferous perennial herb that produces distinct rosettes on a slender rootstock; it produces sexual and asexual seeds that are dispersed by wind (Krahulcova & Krahulec 1999), and glandular hairs cover all vegetative organs (Bishop & Davy 1994). Hieracium pilosella is native to Europe and Eastern Asia, but is an invasive species in New Zealand and North America (Knicker et al. 2000;D ıaz-Barradas et al. 2015). ...
• Plants usually interact with other plants, and the outcome of such interaction ranges from facilitation to competition depending on the identity of the plants, including their sexual expression. Arbuscular mycorrhizal (AM) fungi have been shown to modify competitive interactions in plants. However, few studies have evaluated how AM fungi influence plant intraspecific and interspecific interactions in dioecious species.
• The competitive abilities of female and male plants of Antennaria dioica were examined in a greenhouse experiment. Females and males were grown in the following competitive settings: (i) without competition, (ii) with intrasexual competition, (iii) with intersexual competition, and (iv) with interspecific competition by Hieracium pilosella – a plant with similar characteristics to A. dioica. Half of the pots were grown with Claroideoglomus claroideum, an AM fungus isolated from the same habitat as the plant material. We evaluated plant survival, growth, flowering phenology, and production of AM fungal structures.
• Plant survival was unaffected by competition or AM fungi. Competition and the presence of AM fungi reduced plant biomass. However, the sexes responded differently to the interaction between fungal and competition treatments. Both intra‐ and interspecific competition results were sex‐specific, and in general, female performance was reduced by AM colonization. Plant competition or sex did not affect the intraradical structures, extraradical hyphae, or spore production of the AM fungus.
• These findings suggest that plant sexual differences affect fundamental processes such as competitive ability and symbiotic relationships with AM fungi.
... czerepninii Tupitz. 1996 (Krahulcová, Krahulec, 1999). В Байкальской Сибири этот заносный вид встречается в предгорьях Хамар-Дабана и на Олхинском плато (ст. ...
We present an account of genera Hieracium and Pilosella (Asteraceae) in Baikal Siberia (Irkutsk Oblast’, Republic of Buryatia and Zabaikalskii Krai). We critically checked the Herbarium IRKU (Irkutsk). For the review we used also data from LE, NSK, TK and IRK, as well as selected publications of different authors. Finally, in the Baikal Siberia we revealed 25 species of Hieracium and 11 species of Pilosella. Five species for the whole region (H. filifolium Üksip, H. schischkinii Üksip, H. tuvinicum Krasnob. et Schaulo, P. glomerata (Froel.) Arv.-Touv., P. sulfurea (Döll) F. W. Schultz et Sch. Bip.), three species for Republic of Buryatia (H. irkutense Tupitz., H. subfa-riniramum (Ganesch. et Zahn) Üksip ex Tupitz., P. caespitosa (Dumort.) P. D. Sell et C. West.) and two species for Zabaikalskii Krai (H. fariniramum (Ganesch. et Zahn) Üksip ex Sennikov, H. irkutense Tupitz.) we have found for the first time. Main diversity of Hieracium is limited by Irkutsk Oblast’ and Baikal rift zone, while the most of Pilosella, being adventive plants for the region, occur mostly along the foothills of the Khamar-Daban Ridge, where their area is coincides with refugium of nemoral (broadleaved) flora. We emphasize the modern role of the refugium for naturaliza¬tion of alien plant species in the region.
