CHROMOSOME NUMBERS AND KARYOTYPES OF ALLIUM PRZEWALSKIANUM POPULATIONS

摘要

In this study, somatic chromosome counts were determined in 302 individuals from 43 Allium przewalskianum populations; 90 were diploids (2n = 16, 16 + 113, 16 + 213) and 212 were tetraploids (2n = 32). Of the 43 populations, five were selected for karyotype analysis. Among them, the diploid plants have two karyotypes: 2n = 2x = 14m + 2st (2SAT) and 2n = 2x = 8m + 6sm + 2st (2SAT). The tetraploid has one: 2n = 4x = 28m + 4st. Mixoploidy, Robertsonian translations, and B chromosomes were reported for the first time. In combination with previous chromosome data, the present study reveals a uniform basic chromosomal number (x 8) and uniformity of karyotypes (Stebbins's 2A type), indicating that speciation through polyploidization is less likely in A. przewalskianum, despite the highly diversified habitats it occupies.