Bruchid Resistance Studies in Black Gram Using Molecular Tools

Abstract

AbstractResistance in black gram genotypes towards pulse beetle, Callosobruchus chinensis (Bruchidae: Coleoptera), was evaluated at Annamalai University, South India, using an integrated approach. The differential response of black gram genotypes to bruchids was evaluated under no-choice and free-choice conditions. The genotypes Sekar (G8) and ADT 3 (G6) were preferred the least while RU 16 18 (G18) and VBN (Bg) 4 (G2) were highly preferred. Observations on oviposition, adult emergence, adult emergence, mean developmental days, weight loss, seed damage, growth index, test weight, seed-coat thickness, seed lustre, color, shape, and moisture content were recorded. Based on Dobie susceptibility index (DSI), the genotypes were grouped as resistant (R), moderately resistant (MR), moderately susceptible (MS), and susceptible (S). Grouping of genotypes based on DSI revealed that G8 and G6 were resistant to bruchids as they had the lowest susceptibility index. It was found that G6 and G8 had thick seed coat (0.05 mm) with low seed moisture content and low crude protein. Correlation studies revealed significant correlation of seed damage percentage with oviposition, adult emergence, and weight loss. The direction of relationship as revealed by path coefficient studies showed high effect of adult emergence towards bruchid infestation in both direct and indirect directions. Twenty SSR primers grouped the 20 genotypes into four clusters based on the DICE matrix.KeywordsBronchus beetleBlack gramMolecular genetic tools