Generation mean analysis for powdery mildew resistance in blackgram Vigna mungo L Hepper

Abstract

Blackgram [Vigna mungo (L.) Hepper] is an important grain legume crop grown widely across Asia for its high protein content. However, the productivity of this crop is hampered by biotic stresses like powdery mildew disease caused by Erysiphe polygoni. The present study aims to understand the gene action, variability, inheritance patterns, screening methods and identification of QTLs for powdery mildew resistance in blackgram. newlineThe research was conducted at two different geographical locations of Tamil Nadu (TNAU, Coimbatore and HREC, Gudalur) using a cross between blackgram genotypes of VBN 11 and LBG 17. VBN 11 was susceptible while LBG 17 showed resistance to powdery mildew. Generation mean analysis was carried out using five parameter model namely F1, F2, F3 generations along with parents were evaluated for yield, yield contributing traits and per cent disease index (PDI) of powdery mildew disease at both locations. newlineThe per se performance of parents was inconsistent across locations for plant height (cm), number of clusters per plant and total number of pods per plant indicating genotype x environment interaction. VBN 11 expressed dwarf stature in Coimbatore but was tall in Gudalur. Profuse branching habit of LBG 17 was consistently expressed in both environments. F1 hybrids showed partial dominance for number of branches per plant and number of pods per cluster across newlinelocations. Transgressive segregation was observed in F2 and F3 generations for total number of pods per plant. newlineIn generation mean analysis, additive, dominance, additive x additive and dominance x dominance components were significant for plant height (cm), pod length (cm) at both locations and per cent disease index (PDI) at Gudalur. In Coimbatore, additive, dominance, additive x additive and dominance x dominance were significant for number of branches per plant and number of clusters per plant whereas, in Gudalur, it was significant for the traits 100-seed weight (g) and seed yield per plant (g).