Giemsa C-banding Patterns in Several Species of Phaseolus L. and Vigna Savi, Fabaceae.

Abstract

Karyotypes and C-banding patterns of Phaseolus calcaratus, P. angularis, P. coccineus, P. vulgaris, Vigna sesquipedalis and V. sinensis were studied. Chromosome numbers of all species were counted to be 2n=22, and the karyotypic characteristics, such as total chromosome length, S%, F% and TF% values and C-heterochromatin content (%) were also described. The C-banding patterns of P. calcaratus, P. angularis and V. sesquipedalis are reported here for the first time.Based on the results of karyotype formula and C-banding pattern analyses, the six species were grouped into two groups. P. calcaratus, P. angularis, V. sesquipedalis and V. sinensis (group I) that had the same or similar karyotype formulae had centromeric bands on all the chromosomes. On the other hand, P. coccineus and P. vulgaris (group II) that had similar karyotype formulae lacked centromeric bands on some of the chromosomes but had large heterochromatic blocks on the short arms of some chromosomes. We concluded that P. calcaratus and P. angularis should be grouped in Vigna group (not in Phaseolus nor Azukia) as proposed by Verdcourt (1970).