Genetic variability for grain yield and water use efficiency in blackgram genotypes

Transpiration efficiency (TE, g biomass kg-1 water transpired) is the preferred measure for examining po- tential genetic variation in crop water use efficiency (WUE). TE was assessed gravimetrically from sowing to grain harvest in fifteen blackgram accessions, two checks and two local varieties under well-watered conditions during kharif season. TEbiomass varied from 2.87 - 5.27 g kg-1 and TEseed varied from 1.10 - 2.03 g kg-1 among genotypes. High coefficient of variability was observed for seed yield and TEseed.Total biomass, TEbiomass, HI and water transpired recorded medium coefficient of variability. High heritability in broad sense was observed for seed yield, TEseed and total biomass. High genetic advance as percent of mean was observed for seed yield, TEseed, total biomass and TEbiomass. High heritability coupled with high genetic advance as per cent of mean was observed for seed yield, total biomass and TEseed.TEseed is significantly positively correlated with TEbiomass (0.883**), seed yield/ plant (0.805**), HI (0.757**) and biomass (0.572*). TEbiomass, seed yield per plant, total biomass and HI were the important components of TEseed as revealed by correlation studies.D2 analysis partitioned the nineteen genotypes in to five clusters. The maximum inter cluster distance was observed between cluster II and V (24.94) and III and IV (22.6). Genotypes IC436665, IC343952 and Local II (Cluster III) had high mean values for TEbiomass and TEseed along with total biomass and seed yield. These genotypes should be useful in future breeding programs for higher water use efficiency.