NEW CHROMOSOME NUMBER AND KARYOTYPE ANALYSIS IN FOUR ASTRAGALUS L. (FABACEAE) SPECIES

Karyotype studies were performed in four Astragalus species of A. cornu-carpae, A. mucronifolius, A. talimansurensis from the section Leucocersis and A. crysostachys from the section Hymenostegis. All four species showed ۲n = ۲x = ۱۶ chromosome number and had metacentric and sub-metacentric chromosomes. The size of chromosomes varied from ۰.۷۵ mm in A. talimansurensis to ۴.۰۰ mm in A. cornu-carpae. The species studied differed significantly in the size of their chromosomes and in karyotype formulae indicating the role of quantitative change in the chromatin (DNA) material as well as chromosomes structural changes in the species diversification. The chromosome numbers of all four species studied are new to science. PCA ordination of the species showed their karyotype distinctness and that such data are of no use in the sectional delimitation in Astragalus.

Keywords:

Astragalus , Fabaceae , Karyotype , Iran