Glycine betaine mediated changes in growth, photosynthetic efficiency, antioxidant system, yield and quality of mustard

Abstract

The present experiment was designed to assess the role of glycine betaine (GB) on growth, photosynthetic efficiency, antioxidant system, yield and quality of Brassica juncea L. cv. Pusa Agrani. Four graded concentrations of GB, i.e. 0, 10, 20 or 30 mM were applied as foliar spray at 50 and 70 days after sowing (DAS). The plants were sampled at 80 DAS to analyze growth, physio-biochemical, microscopical and histochemical parameters. Yield and quality parameters were analyzed at 120 DAS. The data revealed that the increasing levels of GB up to 20 mM enhanced growth characters, net photosynthetic rate and its associated attributes, carbonic anhydrase, GB content, proline content, nitrate reductase activity, antioxidant enzymes activities, carbohydrate content, potassium content and yield and quality parameters. Additionally, the graded levels of GB up to 20 mM modulated histochemical studies (superoxide anion and hydrogen peroxide (H2O2) generation) and microscopic studies (stomatal aperture, root cell viability and H2O2 production). No further improvement in various parameters was observed after 20 mM GB. However, proline and GB contents were found to be improved with GB in a concentration dependent manner. It may be concluded that two sprays of 20 mM GB proved to be the best for this crop.