Summary: | The genus Anthoxanthum (sweet vernal grass, Poaceae) represents a taxo- nomically intricate polyploid complex with a large phenotypic variation and still poorly resolved evolutionary relationships. The thesis deals with Anthoxanthum sect. Anthoxanthum in Europe, which comprises five traditionally recognized perennials (A. odoratum, diploid and tetraploid A. alpinum, A. maderense and A. amarum) and three annuals (A. gracile, A. aristatum and A. ovatum). Combination of different methods (DNA flow cytometry, sequencing of nrDNA ITS and two plastid regions, fluorescence and genomic in situ hybridization, climatic niche characterization and spatio-temporal modelling) was used to investigate ploidy and genome size variation of the genus across its European range, and to clarify the species origin and phylogeny of its members. Eight taxonomic groups that predominantly corresponded to traditionally recognized species were delimited on the basis of genome size values and phenotypic variation. While our data supported the merger of A. aristatum and A. ovatum, eastern Mediterranean populations traditionally referred to as diploid A. odoratum were shown to be cytologically distinct and may represent a new taxon. Genuine intraspecific variation in genome size was detected within the genus and the evidence for...
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