Abstract

                                High-temperature stress adversely affects crop production, particularlyreducing the rice yield. It is essential to study the effect of heat stress onmorphological, physiological, and yield responses to develop mitigationstrategies. Hence the present work was carried out by raising Nagina (N22)and Coimbatore 51 (CO51) rice varieties in controlled conditions. Increasedplant height and tiller number were observed in case of high-temperatureconditions, coupled with reduced leaf area and chlorophyll index observed inboth the varieties. Exposure of plants to high temperatures also resulted in areduction of panicle length, panicle weight, and thousand-grain weight, whichultimately resulted in lower grain yield. Percent reduction in physiologicaltraits such as leaf area and chlorophyll index was less in N22 compared toCO51. N22 had the highest panicle length, panicle weight, and thousandgrainweight under heat stress, thus maintaining the yield under stress.

Key words : Rice, morpho-physiological traits, yield components, high-temperature stress