Physio-biochemical and Molecular Characterization of Selected Rice (Oryza Sativa L.) Genotypes to Drought at Flowering Stage

Abstract

Rice (Oryza sativa L.) is an important staple food crop of India as well as whole world. It is second most cultivated cereal in the world and most widely consumed staple food for about 60% of the world’s population. Drought stress is one of the major abiotic stresses, which adversely affects crop growth and yield. In present study, a pot experiment was conducted with 20 rice (1 Non Basmati and 19 Basmati) genotypes during kharif season 2018 and 2019 at field laboratory, Department of Agricultural Biotechnology, S.V.P.U.A.&T., Modipuram, Meerut, U.P., India in Completely Randomized Design (CRD) with three replications. During the diversity analysis of twenty varieties, a dendrogram was constructed, which generate two major groups i.e. cluster I, cluster II along with two single genotypes namely Punjab Basmati 2 and Basmati-564. The maximum similarity exhibited by genotype Vallabh Basmati 24 with Vallabh Basmati 21 and the minimum similarity was shown by genotypes Vallabh Basmati 21 with Punjab Basmati 2. Drought treatment was given for 10 days at flowering stage by restricting the water to treated pots, whereas regularly watering was applied to control pots. The screening of rice genotypes was done on the basis of various morphological, physio- biochemical and molecular parameters. Further, the study suggests that, drought has negatively impacted on all the varieties used in the experiments regardless of their stress response nature. The impact of drought stress varied among the plant varieties, where Nagina 22, a drought tolerant variety under drought stress was found significantly superior over all other investigated varieties in the morpho-physio-biochemical parameters followed by Pusa Basmati 1121 variety. Whereas Basmati 386 as found significantly lower than all other tested varieties. Furthermore, these varieties were selected for drought responsive gene expression analysis. Results of expression analysis showed that Nagina 22 (tolerant variety) have higher level of drought responsive gene expression. Comparatively, Pusa Basmati 1121 showing the comparatively low level of drought responsive gene expression than Nagina 22. Whereas, Basmati 386 variety having very low level of drought responsive gene expression.