Diversity in CMA- and DAPI-Banded Regions in Ten Germplasms of Crotalaria from Bangladesh

Abstract

Ten germplasms of three Crotalaria species viz. C. pallida (Acc. No. 4250, 4803, 4805, 4806, and 4807), C. incana (Acc. No. 4790, 4801, 4804, and 4809), and C. juncea (Local) were investigated cytogenetically through Chromomycin A₃ (CMA) and 4′-6 diamidino-2-phenylindole (DAPI) fluorescent bandings. After CMA-banding, 10 Crotalaria germplasms showed 31 centromeric and 34 terminal bands which indicated a tendency of accumulating GC-rich sequences at centromeric regions or chromosomal ends. The number of DAPI bands was less than that of the CMA bands found in different germplasms of Crotalaria. Maximum terminal DAPI-bands indicated a tendency of accumulating AT-rich sequences at the chromosomal ends. Few chromosomes of Acc. No. 4803 of C. pallida and 4804 of C. incana could be used as a marker of respective germplasms due to their unique DAPI-banding pattern. Fluorescent banding revealed the occurrence of genomic alteration within these germplasms. In Acc. No. 4790 and 4804 of C. incana, 2n=17 chromosomes were observed indicating its the aneuploid origin that correlates with their phenotypic features like seedless pod formation. The diversity in CMA- and DAPI-banded regions in ten germplasms of Crotalaria from Bangladesh can help in further breeding programs.