Effect of high temperature studies on morphological traits of rice (Oryza sativa L.) genotypes for temperature tolerance

Abstract

High temperature (HT) stress affects grain yield of rice. High temperature stress is the one of the most important environmental factors that influencing growth, development, and yield of rice crop. A field experiment consisted of 50 IRRI and Indian rice genotypes with five check (Local, national and international) varieties were evaluated during normal sown (December-2014) and late sown conditions (January 2015) on various morphological parameters at different stages of growth for high temperature tolerance. Results indicated that HT stress decreased the mean grain yield of late sown condition as compare to normal sown condition by 11.92 percent which was expected that plant experienced the high temperature stress mainly during flowering and grain filling stages. The results of mean sum of squares due to the genotypes and their interaction were significant for different morphological parameters and yield attributes viz..., late sown condition significantly decreased in rice genotypes particularly, in case of high temperature sensitive genotypes. The growth parameters leaf area index, numbers of productive tillers, flag leaf length, dry matter production per plant and grain yield per plant was higher in the following genotypes EC792239, EC792185, EC792179, EC792240 and EC792316 are identified as heat stress tolerant genotypes. They could be used as potential donors for development of heat stress tolerant variety.