Root responses under water deficit stress: unraveling the impact on wheat crop and the ameliorating role of brassinolide

Aim: To identify changes in root system architecture traits of wheat due to exogenous application of epibrassinolide for the alleviation of negative impact of low moisture stress in wheat crop. Methodology: On the basis of growth performances one set of contrasting wheat genotypes were identified (HD-2733, relatively stress tolerant and DBW-187 relatively stress sensitive). Similarly, brassinosteroids (BRs) concentration was selected by pilot experiments, wherein 0.01mM performed best among all. Taking all these results into consideration, four treatments (T0=well-watered, T1=water deficit, T3=EBL + well wateredandT4=EBL + water deficit) were maintained for evaluation of root architectural traits, biomassand grain yield per plant. Results: The tolerant genotype (HD-2733) showed better tolerance in almost all root traits and in yield as compared to the sensitive genotype (DBW-187). epibrassinolide under water deficit condition was found to be effective as the root trait values were higher for root length, root volume, root surface area and root biomass under EBL+ water deficit treatment as compared to water deficit. Shoot biomass was highly sensitive to water deficit as the biomass allocation under water deficit was more towards root as compared to shoot. Interpretation: Epibrassinolide can be a potent biochemical to improve the root characteristics as well as yield per plant. Seeds of tolerant genotype treated with 0.01m M EBL even under low moisture stress can be recommended. Key words: Epibrassinolide, Root system, Wheat, Water deficit