In order to study the magnitude and consistency of yield response to drought and to identify genotypes that confer drought resistance, a series of experiments with 12 selected genotypes in advanced yield trial lower than 100 days (AYTLT 100) on the basis of observational yield trial (OYT) performance were conducted under vegetative stage drought stress and irrigated conditions at CRRI, Cuttack for three years. Significant genotype x environment interactions were observed for days to maturity, plant height, harvest index and grain yield and having homogenous error variance in environments for these characters. Among the linear and non linear components, G x E interactions were predominant for most of the characters, suggesting variation in the performance of different genotypes grown over environments could be predicted. Based on the stability parameters, the genotypes Vandana and CB 0-13-1 were found to be stable. To some extent, genotype IR 76569-259-1-1-3, RR 383-2 and Kakro may satisfy stability parameters but being low yielder, it remains questionable. Genotypic variation in drought susceptibility index (DSI) was consistent among the most of the experiments and mean DSI ranged from 0.57 to 0.91. Simultaneously, Lalsar, RR 440-167-2-13, CR 143-2-2 and IR 76569259-1-1-3 estimated lowest DSI for yield and all component characters. Grain yield reduction due to drought ranged from 64 to 82%. The results indicated that selection for yield and yield components under stress is reliable but selection under non stress is inefficient in estimation of the yield performance of genotypes under stress condition, particularly in severe drought condition. The top genotypes under stress viz. Lalsar and CR 143-2-2 were accepted drought tolerant genotypes which may be used as the genetic sources in breeding programme. Vandana may be suggested as the best tolerant genotype for cultivation under vegetative stage drought stress.
Upland rice, drought, stability, coefficient of determination, DSI
