Correlation studies of yield components and grain quality of Oryza sativa under drought stress

The purpose of the current research was to investigate 6 rice genotypes (Swarna-Sub1, IR-44-Sub1, IR-07-F289-Sub1, Ciherang-Sub1, Nagina-22 and IR-64) under reproductive stage drought stress. Field experiment was laid out with triplicate randomized complete block design in split-plot fashion. The drought stress was applied at booting stage to onwards for 30 days. Results of ANOVA indicated that drought stress significantly reduced the overall performance of all the genotypes under study. Correlation studies showed that grain yield per plant was highly significant and positively correlated with fertile spikelets per panicle, fertility percentage and harvest index while highly significant negatively correlated with panicle length and sterile spikelets per panicle. Nine drought stress indices were also calculated for grain yield per plant. GM, HM, YI, YSI and RSI showed highly significant positive correlation with crop performance under drought conditions thus these indices can be used for the selection of drought tolerant genotypes. The first two principal components (eigenvalues > 1) described 99.29% of the overall variation in yield performance, according to PCA data. Nagina-22 and Swarna Sub1were identified as superior genotypes based on the results of indices and their association and PCA analysis. The information obtained from this study can be exploited in future drought screening and breeding programs.