Archives of Current Research International

High temperature is a major abiotic stress in the globe as the mean temperatures are rising. Keeping in view the changing climate scenario it is essential to identify rice genotypes that can tolerate rise in the temperature. A field experiment was conducted to evaluate rice genotypes for high temperature tolerance under artificial polyhouse. The increase in mean maximum temperature was 3.6^oC and mean minimum by 1.6^oC under polyhouse. High temperature stress resulted in a mean reduction of days to maturity by four days, though days to 50% flowering were unaffected. Plant height among the genotypes decreased slightly by 1–3 cm under stress. Mean chlorophyll content declined under high temperature conditions however, IET 31444, IET 30651, and IET 31510 had higher chlorophyll levels under stress. Yield and yield components were adversely affected. Yield reduced by 22.1% over control. Spikelet fertility, grain yield, Total dry matter and harvest index reduced in all the tested genotypes under high temperature conditions. Among the genotypes, N22, IET 31510, IET 31444 and MTU 1290 exhibited superior performance under heat stress, maintaining higher spikelet fertility, grain yield and test weight, indicating better tolerance. In contrast, Vandana, IET 30505, and IET 29694 were highly susceptible, showing significant yield reductions. These findings emphasize the existence of genotypic variability in high temperature response and identify promising heat-tolerant lines for use in breeding programs aimed at developing climate-resilient rice varieties.