Abstract

This study was conducted to detect the genetic diversity of sixty eight cowpea (Vigna unguiculata) accessions mainly from Myanmar on the basis of protein subunit variations. Fourteen polymorphic bands were recorded out of total 18 resolution bands and the banding pattern revealed four regions. The UPGMA dendrogram showed two distinct clusters. It revealed random grouping of different colored genotypes that indicated no response for discriminating cowpea for different seed-coat color genotypes. Some accessions exhibited a considerable amount of variations although its magnitude was limited through SDS-PAGE 11.25 slab gel. To be broadened, the genetic diversity of cowpea, interspecific hybridization between cowpea and the Asian Vigna was conducted. The intermediate band patterns of F1 hybrids were detected from the cross between mungbean and cowpea and thus it confirmed that they were true hybrids by SDS-PAGE analysis and species-specific Simple Sequence Repeat (SSR) primer. It is suggested that SDS-PAGE can also be used as a promising tool to detect genetic relationships of Vigna interspecific hybrids because differences were found between known genetic similarities of both parents.

Key words: Cowpea, cross compatibility, genetic relationship, SDS-PAGE, UPGMA dendrogram.