Chromosome studies in four species of Saxifraga L. (Saxifragaceae) collected in Tuva and adjacent regions, Russia

Four species of Saxifraga such as S. aestivalis, S. hieracifolia, S. foliolosa and S. hirculus were collected in Russia and observed their somatic chromosome numbers. Saxifraga aestivalis showed the somatic chromosome number of 2n=28, S. hieracifolia showed that of 2n=114, S. foliolosa showed that of 2n=60, and S. hirculus showed that of 2n=16. These chromosome numbers verifi ed with the previous reports, expect for S. foliolosa. The chromosome numbers of 2n=60 for S. foliolosa was reported here for the fi rst time. Chromosome sizes of four species varied in mean lengths with each others; S. aestivalis and S. foliolosa had small-sized mean chromosomes 1.31 μm and 1.47 μm long respectively, S. hieracifolia had medium sized, mean chromosome 2.75 μm long, and S. hirculus had large sized, mean chromosome 4.4 μm long. Saxifraga aestivalis had a bi-modality and decrease in chromosome size from the largest to the smallest chromosomes, while the other three species had mono-modal or gradual decrease in chromosome size from the largest to the smallest chromosomes.