Karyotypic variability in some species of the genus Chondrilla (Asteraceae)

Karyotypic variability of plants was evaluated in 17 populations of six species of the genus Chondrilla (C. ambigua Fisch., C. brevirostris Fisch, et Mey., C. laticoronata Leonova, C. canescens Kar., Kir., C. juncea, C. pauciflora Ledeb.) in the Astrakhan, Voronezh and Saratov regions, the Republic of Kalmykia, and Western Kazakhstan. It is maintained that C. ambigua is a strict diploid (2n = 2x = 10) species, while its close relative - C. pauciflora - is a strict triploid (2n = 3x = 15) taxon. The research demonstrates that the plants of the apomictic taxa C. brevirostris, C. canescens, C. juncea and C. laticoronata are characterized by the genomic instability in the form of chromosome instability which results in these species’ mixed-ploidy populations.