Character Association Analysis on Morpho-physiological and Yield Parameters of Rice (Oryza sativa L.) under Water Stress

Abstract

The present character association study aims to understand the correlation between morphological, physiological and yield traits of rice genotypes under water stress and non-stress conditions, so as to identify the differentially expressing traits under both the conditions. Such differentially expressed traits with positive influence on yield can serve as selection criteria for selection of stress tolerant plants. The experiment was carried out using randomized complete block design with three replications at the department of plant breeding and genetics, college of agriculture, Kerala Agricultural University between December 2021 and March 2022. Sixteen characters pertaining to morphological, physiological and yield of three rice genotypes were recorded under reproductive stage water stress and non-stress conditions. The intensity of trait correlations varied significantly under drought and non-drought conditions. The results of correlation studies indicate positive and significant correlation of grain yield with number of tillers, 1000 grain weight, photosynthetic rate, inter cellular CO2 content and water use efficiency under well-watered condition and of these, 1000 grain weight, and inter cellular CO2 content had significant positive influence on grain yield under drought stress. Principal component analysis results indicated two principal components i.e., PC1 and PC2 accounted for 70.5% and 29.5% of the total variation in grain yield under drought and 89% and 11% respectively under non drought conditions. Correlation and principal component analysis concluded that plants with higher grain weight along with improved high internal carbon dioxide content in leaves can be selected for attaining high yield potential under drought and non-drought conditions and will serve as climate adaptive crops under varying soil moisture levels.