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Brassica campestris var. Agrani, B. juncea var. BARI Sharisha-16 (BS-16) and B. napus var.
BARI Sharisha-13 (BS-13) are the three different oilseed crops belonging to the genus Brassica,
have been investigated to amass genetic information through cytogenetic characterization by
orcein staining and to unveil phylogenetic relationships among these three species by
karyomorphological analyses with respect to their asymmetry indices. B. campestris var. Agrani,
B. juncea var. BS-16 and B. napus var. BS-13 were found to possess different somatic
chromosome number along with varied karyotype formulae, 2n=20=20m, 2n=36=30m+6sm and
2n=38=34m+4sm, respectively. The investigation also aimed at exploring the genetic divergence
and selection of improved variety among the three Brassica species by protein banding pattern
obtained from polyacrylamide gel electrophoresis (PAGE). According to Nei’s genetic distance
analysis, the highest genetic distance found between B. juncea var. BS-16 was 0.4700.
Contrastingly, the lowest genetic distance found between B. campestris var. Agrani and B. napus
var. BS-13 was 0.2877. B. juncea var. BS-16 was found at distant position in the phylogenetic
tree and may displayed diverse nature from other two species of Brassica L. The values of
different karyomorphological indices also presaged that B. juncea var. BS-16 exhibited some
degree of asymmetry and may express with relatively advanced nature than the other two studied
species in respect of evolutionary perspective. Therefore, this study regarding detailed
karyomorphological data and determination of genetic relationship would be beneficial to the
breeders of Brassica for proper characterization, designing upcoming breeding programs and
conservation purposes of plant genetic resources of Brassica variants.
Keywords: Karyotype, Asymmetry, PAGE, Brassica L.