Biosystematic study of the diploid-polyploid Pilosella alpicola group with variation in breeding system: Patterns and processes

Members of the Pilosella alpicola species group (Asteraceae) are distributed throughout the alpine region of the European mountains (Alps, Carpathians, Balkan mountains). Like other Pilosella species groups (Hieracium subg. Pilosella ), the taxonomy and species' relationships are poorly understood mostly due to widespread facultative apomixis, frequent hybridization and polyploidization—the most important phenomena substantially involved in the evolutionary history of the genus. We assessed morphology, ploidy level, variation in breeding system and molecular variation within the P. alpicola group to provide a new taxonomic concept and to clarify evolutionary relationships among species and origin of polyploids. Multivariate morphometric analyses (UPGMA, CDA, PCA) applied on 324 plants originated from 21 populations revealed existence of four well-separated clusters corresponding to four allopatric taxa: P. alpicola s. str. (Alps), P. rhodopea (Balkan Peninsula, Southern Carpathians), P. serbica (Serbia and Montenegro) and P. ullepitschii (Carpathians). In total, four ploidy levels (2 x, 3 x, 4 x, 5 x ) were detected among 557 plants analysed from 19 populations by classical chromosome counting and flow cytometric analysis. The tetra- and pentaploids of P. alpicola s. str. have an allopatric distribution (Wallis Alps vs. Dolomites, respectively). Four ploidy levels with complex cytogeographic pattern and high frequency of mixed ploidy populations (75%) indicating a primary contact zone were recorded inP. rhodopea. Pilosella ullepitschii andP. serbica are exclusively diploid and are both sexually reproducing. In spite of a clear morphological separation, a molecular analysis (ITS and cpDNA sequences) suggests close relationships and rather recent origin of all studied taxa, except P. alpicola s. str. The latter taxon is an agamospermic allopolyploid that likely originated polytopi cally from a hybridization between P. rhodopea from the Balkans and P. glacialis from the Alps. In contrast to P. alpicola s. str., our data strongly support an autopolyploid origin of P. rhodopea polyploids which reproduced strictly sexually. Pilosella petraea , sometimes treated as a member of the P. alpicola group, differs from the remaining taxa by its conspicuous morphology, ecology and ITS polymorphism and should be removed from the group. Range shifts and extinctions were likely involved in shaping the evolutionary and modern distributional pattern of the group. Our combined methodological approach enabled us to propose a new taxonomic circumscription for the P. alpicola group and revealed auto- and allopolyploidization events

Viola suavis var. pannonica (Violaceae), a new white-flowered violet from central Europe

Viola suavis var. pannonica (Violaceae) from central Europe is described here as a new variety to science. It is most similar to the blue-flowered V. suavis var. suavis and the white-flowered V. suavis var. catalonica and V. suavis subsp. naqshii, but exhibits differences in several characters, such as petal colour, spur shape, fimbriae length on the stipules, bracteoles position on the peduncle and lamina sinus shape. Although the new taxon is often considered a colour mutation of V. suavis var. suavis, previous genetic analyses revealed that these white-flowered plants do not arise recurrently at different locations (having multiple origins), but rather form a monophyletic evolutionary lineage. To date, the occurrence of V. suavis var. pannonica has been reported in the Slovak Republic, the Czech Republic and western Ukraine. In this paper, we report its occurrence in Austria and Hungary. Notes on its etymology, distribution, ecology, origin and hybridization, as well as photographs of the new variety (including the holotype) are also provided

Viola suavis var. pannonica (Violaceae), a new white-flowered violet from central Europe

Viola suavis var. pannonica (Violaceae) from central Europe is described here as a new variety to science. It is most similar to the blue-flowered V. suavis var. suavis and the white-flowered V. suavis var. catalonica and V. suavis subsp. naqshii, but exhibits differences in several characters, such as petal colour, spur shape, fimbriae length on the stipules, bracteoles position on the peduncle and lamina sinus shape. Although the new taxon is often considered a colour mutation of V. suavis var. suavis, previous genetic analyses revealed that these white-flowered plants do not arise recurrently at different locations (having multiple origins), but rather form a monophyletic evolutionary lineage. To date, the occurrence of V. suavis var. pannonica has been reported in the Slovak Republic, the Czech Republic and western Ukraine. In this paper, we report its occurrence in Austria and Hungary. Notes on its etymology, distribution, ecology, origin and hybridization, as well as photographs of the new variety (including the holotype) are also provided

A new cytotype of Jacobaea vulgaris (Asteraceae): frequency, morphology and origin

Jacobaea vulgaris subsp. vulgaris (syn. Senecio jacobaea subsp. jacobaea) constitutes an intricate polyploid complex distributed in Europe. Four cytotypes have been reported in this species, three with euploid (diploid, tetraploid and octoploid; 2n020, 40 and 80) and one with aneuploid (2n 032) chromosome numbers. Here we report that the diploid chromosome number (2n020) reported from Bulgaria is due to misidentification with Jacobaea aquatica. On the other hand, we have discovered a new, hexaploid (2n 06x060) cytotype within J. vulgaris subsp. vulgaris using flow cytometry. The new cytotype occurs within four sympatric populations of otherwise tetraploid and octoploid plants in Pannonia (one locality in the eastern Czech Republic and two localities in southwestern Slovakia) and in Podillya (one locality in western Ukraine). The frequency of hexaploid individuals within 76 studied populations is very low (only 10 of 693 analysed plants), and hexaploids probably represent hybrids between tetraploid and octoploid plants. Three mixed populations with hexaploid plants were subjected to detailed morphological and pollen fertility analyses. Multivariate morphometric analysis reveals partial separation of tetraploid and octoploid plants, whereas hexaploid individuals are similar in morphology to octoploids. In comparison with tetraploids, octoploids and hexaploids exhibit slightly longer ray florets, involucral bracts and tubular florets and more hairy outer achenes. Hexaploid plants display larger pollen grains and lower pollen fertility compared to tetraploids and octoploids