Abstract

Morphometric and biochemical characterization of eighteen rainfed upland rice genotypes were studied under drought stress situation. Relation of the studied traits was also observed with grain yield under drought stress situation. A significant variation among the rice genotypes were observed and a significant genotype × environment interaction for all the traits was seen indicating better scope for drought tolerance and improvement in  yield. The different biochemical parameter that is, shoot starch at maturity, leaf’s starch, upper root’s and lower root’s carbohydrate under both the conditions were positively increased. However, proline in irrigated condition was the only trait which possessed very high estimates of phenotypic and genotypic coefficient of variation, heritability (h²_b) and genetic advance (Ga). Traits like, chlorophyll a, nitrate reductase activity, carbohydrate at flowering, starch at maturity, leaf’s carbohydrate, leaf’s starch and lower root’s starch showed positively high (desired) genotypic correlation as well as direct effect on grain yield. SDS-PAGE profiling in control and drought condition was conducted and 25 kDa proteins was found to be induced in resistance rice genotypes. Drought tolerance of well-known cultivars- Vandana, NDR-359, Azucena, Moroberekan, P-0326 and TN-1 (DSI<1 & DTE>75%) was validated through biochemical as well as physiological characterization in the study. These traits showed a promise for selection parameters for the drought stress situation.

Key words: Correlation, drought susceptibility index, drought tolerance efficiency, path coefficient, genetic advance, upland rice and variance.