Format: ORAL

Michal Hrone, David Hork, Gabriela Stryhalov

Department of Botany, Palacký University in Olomouc, Olomouc, Czech Republic

Geophyte monocots with their showy flowers are a prominent component of the Mediterranean flora. However, they remain taxonomically challenging due to their low vegetative morphological variability and the presence of polyploidy. We studied genome size as a proxy for ploidy level of selected taxa of Gagea (Liliaceae) and Ornithogalum (Asparagaceae) and we also established their pollen stainability. We asked whether genome size can be used for taxa determination and whether pollen stainability correlates with established ploidy level. We expected a normal pattern of pollen stainability with diploids having the highest proportion of well-developed pollen and even ploidy cytotypes having higher stainability than odd ploidy cytotypes. In both genera, we found an excessive occurrence of polyploidy ranging from diploids to heptaploids. The studied taxa differed in genome size also on the same ploidy level suggesting that genome size can be used for taxa differentiation. Quite surprisingly, pollen stainability varied greatly and it did not follow the expected pattern with higher ploidy and odd ploidy cytotypes usually having a higher proportion of well-developed pollen. A simple mechanistic explanation of this pattern is lacking. Lower stainability in even ploidies suggests past hybridisations and/or meiotic aberrations.