engleski

BalkBioDiv- Insights into plant diversity of the Balkan Peninsula. Polyploid evolution of Cerastium, Knautia and Sesleria

An important source of biodiversity is polyploidy (multiplication of chromosome sets), which is an important mechanism allowing sympatric speciation. In the frame of an EU-funded See-Era.Net Plus project we have studied the spatiotemporal diversification of three polyploid plant genera, which have their centres of diversity on the Balkan Peninsula: Cerastium (Caryophyllaceae), Knautia (Dipsacaceae) and Sesleria (Poaceae). We sampled 360 populations of Cerastium, 375 of Knautia and 450 of Sesleria. Measurements of the genome size using flow cytometry show striking similarity of genome sizes across different taxa belonging of the same ploidy in Knautia and Sesleria, whereas in Cerastium the monoploid genome size differs considerably among different taxa of the same ploidy. Also divergence of nuclear and chloroplast DNA sequences is much higher in Cerastium, often following the taxonomic boundaries. On the contrary, the lineages revealed in Knautia and Sesleria are mostly geographically correlated. Preliminary analyses of the DNA sequences as well as the AFLP fingerprinting methods indicate that polyploidisation has taken place in many different lineages of the three genera, but the timescale was likely different, older in Cerastium and younger in Knautia and Sesleria. Further analyses to comprehensively disentangle the evolutionary history of the three study groups are underway.

Polyploid evolution; Cerastium; Knautia; Sesleria; Balkan

nije evidentirano