Genetic relationship in Vigna mungo (L.) Hepper and V-radiata (L.) R. Wilczek based on morphological traits and SDS-PAGE

Thirty seven diverse genotypes of Vigna mungo and three of V. radiata resembling to V. mungo for seed characters were studied to determine the extent of genetic variation based on morphological characters. In addition, 4 black seeded genotypes in each species and 8 green seeded V. radiata genotypes were included for SDS-PAGE analysis. Seed proteins were analyzed through slab type SDS-PAGE. High variance was observed for plant height, days to flowering, days to maturity, number of branches/plant, number of pods/plant, pod length, seeds per pod, biomass yield/plant, grain yield/plant and harvest index (%) during 2 consecutive years. First four components of PCA with eigenvalues >1 contributed 78.7 and 79.1% of the total variance amongst 40 genotypes during 1998 and 1999. The populations with high PC1 values were expected to be high yielding characterised by earlyness, high seed weight and harvest index, all traits strictly related to reproductive phase. Four clusters of genotypes were observed during both the years and genetic diversity was in association for both the years. Based on SDS-PAGE, specific bands were suggested to be used for identifying Vigna radiata from mixed germplasm with Vigna mungo. The SDS-PAGE proved to be a powerful tool for differentiating Vigna radiata and Vigna mungo, whereas a low level inter-specific genetic diversity was observed and no clear differentiation was observed both for agronomic characteristics and for geographical origin.