2013 Volume 78 Issue 1 Pages 73-79
Five commercial cultivars of Vigna unguiculata ssp. sesquipedalis (L.) Verdc., viz. Lalbanie, Kagornatki, BARI Borboti-1, White Bean, and Saba, were investigated cytogenetically and at the molecular level for characterization. Although the five cultivars possessed an identical chromosome number (2n=22), they showed variation in respect of other karyotype features. Maximum metacentric chromosomes were found in Saba. The karyotype formulae of Lalbanie, Kagornatki, and White Bean were more or less similar while BARI Borboti-1 was quite different, since in addition to metacentric and sub-metacentric chromosomes, a telocentric chromosome is present in its karyotype. The total length of 2n chromosome complements of Saba was the largest. Different total lengths of diploid complements among these cultivars indicated the deletion of heterochromatic regions. The five cultivars showed distinct CMA-banded karyotypes which were specific for each variety. Heteromorphicity in respect of CMA-band was found in Lalbanie and Saba, suggesting the deletion of heterochromatic banded portion from the respective chromosomes. The highest percentage of GC-rich regions was found in BARI Borboti-1, while the lowest was in Saba. The reason for the variation in the percentage of GC-rich regions is probably the tandem duplication of GC-rich repeats. In spite of a few common RAPD bands, each cultivar has distinct RAPD-fingerprinting pattern. The common band revealed that the five cultivars share similar fragments. Lalbanie, BARI Borboti-1, White Bean, and Saba showed unique bands, useful as specific markers for these varieties. Therefore, with the help of cytogenetical and RAPD analysis, it was possible to characterize each cultivar of Vigna unguiculata ssp. sesquipedalis (L.) Verdc.
