Limited genome size variation in Sesleria albicans

Abstract

The extent and significance of intraspecific genome size variation in plants continues to be a matter of discussion: in some species considerable variation has been described, while no variation has been detected in other taxa. In the present study, intraspecific genome size variation was analysed in a perennial gross Sesleria albicans Kit. ex Schult. (Poaceae). Flow cytometry was used for the analysis of nuclear DNA content in ten geographically isolated populations of S. albicans. Despite long-term isolation and lack of gene-flow between the populations, only negligible inter-population differences were found. Although the differences between the populations were statistically significant, the maximum inter-population difference reached only 1.6% of the mean 2C value (9.78 ± 0.04 pg). The variation was not correlated with geographical location or with altitude of the populations analysed. The present study clearly demonstrates that S. albicans belongs to the plant taxa with a highly stable genome size. (C) 2000 Annals of Botany Company.