Effectual tolerant traits for grain yield in rice genotypes grown under drought

Abstract

In agriculture, screening against drought stress is not only the matter of adaptation but also its productivity. The present work was conducted with a question to elucidate efficient drought sustaining characters that contribute positively to grain yield. Eight genotypes of same maturity group showing partial tolerance to drought were used as study materials in two different situations, one as control in the field condition and drought stress was imposed in the rain out shelter. Result showed variation amongst genotypes response for root morphological traits. Genotype BRR-0028 showed maximum R:S with 0.613, RDM with 0.317 and RMF with 0.273 as compared to other genotypes. Observation of increasing percent in photosynthetic rate under drought stress is remarkably good index for tolerance genotyoes, whereby genotype BRR-0028 showed maximum increased in the photosynthetic rate with 13.03 % revealing more tolerant. Increased activities of antioxidant enzymes like peroxidise (POD), catalase (CAT) and superoxide dismutase (SOD) scavenging reactive oxygen species i.e. hydrogen peroxide and superoxide anion in the genotypes with higher CSI was observed. Amongst the genotypes studied, BRR-0026 (23.06) and BRR-0028 (22.09) showed higher in soluble protein content. Out of eight genotypes, Sabour Ardhjal recorded the highest proline content with 69.9 µg g-1 fresh wt. Correlation study revealed a positive association amongst physiological parameters. Photosynthetic rate was positively correlated with total chlorophyll content, transpiration rate and stomatal conductance. However, correlation of tolerant traits with yield showed inefficiency of many studied tolerant traits in regards to grain yield. Morphological traits R:S has direct association with grain yield in rice in both the control and drought stress at the level of p