Cytogeography of Taraxacum venustum and T. shikotanense (Asteraceae) in Japan

Abstract

We report on polyploidy, karyotypes, and cytogeographical distribution of two species of native agamospermous Taraxacum in Japan. Taraxacum venustum had two polyploid numbers of 2n=3x=24 and 2n=4x=32. Four karyotypes were found in tetraploid plants. In T. shikotanense, there were seven chromosome numbers: 2n=47 (hypohexaploid), 48 (hexaploid), 56 (heptaploid), 64 (octoploid), 72 (nonaploid), 80 (decaploid), and 88 (undecaploid). Our study reveals that some races in both T. venustum and T. shikotanense can be differentiated according to their polyploidy and karyotypes.