Naslov
Disentangling the polyploid evolution of the genus Knautia (Dipsacaceae)

Autori
Frajman, Božo ; Rešetnik, Ivana ; Schönswetter, Peter

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
15. Treffen der Österreichischen Botanikerinnen und Botaniker, Innsbruck (27.-29.9.2012). Berichte des naturwissenschaftlich-medizinischen Vereins in Innsbruck / - Innsbruck, 2012, 17-17

Skup
15. Treffen der Österreichischen Botanikerinnen und Botaniker

Mjesto i datum
Innsbruck, Austrija, 27.09.2012. - 29.09.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
Knautia; phylogeny; polyploid evolution

Sažetak
The genus Knautia comprises ca. 60, mostly European species, with highest diversity in southern Europe (the Balkan and Iberian Peninsulas, as well as the Alps and Apennines). The species-poor diploid sections Knautia and Tricheroides comprise mostly annuals centered in the eastern Mediterranean, whereas the section Trichera includes mainly perennials. Many of them are diploids (2n=20), but polyploidisation to the tetra- and hexaploid levels occurred within almost all traditionally recognised groups. Measurements of the relative and absolute genome size of 360 populations belonging to 50 species show striking similarity of genome sizes across different taxa belonging to the same ploidy level, with the exception of most Iberian taxa (e.g., K. rupicola and K. subscaposa) whose genome size is divergent. Ploidy-level screening across populations reveals also multiple ploidy levels within some taxa that were thought to be uniform in the ploidy level (e.g., K. illyrica). Preliminary molecular phylogenies of the ribosomal nuclear ITS and plastid ycf6-psbM regions are poorly resolved and do not follow the taxonomic boundaries. The plastid and nuclear datasets are only partly congruent, possibly due to hybridisation among different taxa, and the groups revealed correspond to some extent to the geographic origin of the included populations, e.g., certain taxa from the Apennines, the Massif Central, the Western Alps and the Iberian Peninsula form strongly supported clades. On the contrary, some Italian populations/taxa exhibit a strong link with populations from the Balkan Peninsula. Iberian taxa with divergent genome size are phylogenetically inconspicuous. The overall shallow structure in ITS and cpDNA data suggests a relatively young age of the diversification of section Trichera and the occurrence of the same haplotypes across large geographical distances implies recent and fast range expansion. Furthermore, sequence as well as AFLP data suggest that infrageneric classification and circumscription of traditional groups are not congruent with actual evolutionary lineages and that polyploidisation was an important speciation mechanism within most intrageneric groups.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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