GENETIC VARIABILITY AND PHYSIOLOGICAL, BIOCHEMICAL, AGRO-MORPHOLOGICAL RESPONSE TO DROUGHT RESISTANCE IN UPLAND RICE (Oryza sativa L.)

Eighteen genotypes of upland rice were evaluated for grain yield and 17 biochemical traits for estimation of direct selection parameters. The entries were evaluated in Randomized Block Design with 3 replications under normal and drought condition during wet season in 2 years. Starch at maturity, soluble carbohydrate upper root, leaf starch, proline content and CHO lower root exhibited high phenotypic (PCV) and genotypic (GCV) coefficients of variation along with high heritability and high genetic advance under irrigated conditions. Under drought conditions, starch at maturity, starch lower root, starch at flowering, CHO at maturity, CHO lower root, leaf CHO, CHO at flowering, grain yield, starch upper root, chlorophyll b, CHO upper root and leaf starch showed high estimates of PCV, GCV, heritability and genetic advance in per cent of mean. The traits mentioned above emerged as ideal traits for improvement through selection in respective environments owing to their high variability and transmissibility. The results revealed that the estimates GCV, PCV, heritability and genetic advance were higher in drought conditions as compared to normal conditions for majority of biochemical traits under study. The adverse drought conditions appeared to unfurl greater degree of variability and transmissibility in the yield as well as biochemical traits. Therefore, greater possibility of improvement in biochemical traits through selection appears in drought condition than control condition.