Physiological and biochemical traits as tools to screen sensitive and resistant genotypes of Brassica juncea exposed to drought stress

Impact of drought stress on physiological and biochemical changes were evaluated in five Brassica juncea genotypes at three different growth stages in a pot experiment i.e., water stress imposed at branch initiation, flower initiation and siliquae formation stages in the form of 45, 60 and 90 (DAS) days after sowing. The study revealed that heat stress decreased chlorophyll content, chlorophyll stability index (CSI) and relative water content (RWC) in all the genotypes. In contrast, drought stress induced an increase in proline, relative stress injury (RSI) and soluble sugar content in all genotypes. The drought susceptibility index (DSI) for seed yield and its attributes were recorded to characterize the relative tolerance of genotypes which clearly distinguish Brassica juncea genotypes into drought tolerant and susceptible cultivars. Noteworthy in comparison to the drought-sensitive varieties, Brassica genotype that possessed higher degrees of drought tolerance Genotypes Kranti displayed higher chlorophyll content, CSI, RWC, soluble sugar content, better osmoregulating ability with the increase in proline content and lower level of membrane injury index. The findings of the present research investigation recommended the growing of Kranti genotypes in the drought prone areas to obtain high economic yield even in adverse condition.