Exploring Genetic Variability for Yield and Its Attributing Traits in Rice (Oryza sativa L.) under Low Soil Phosphorous Condition

Phosphorus (P) is a vital macro-nutrient essential for the growth and development of all crop plants including rice. Inadequate availability of P in the soils hinders crop growth, resulting in reduced rice yields. Genetic variability for low P tolerance is of utmost importance to understand the genetics and improvement of rice genotypes for the trait. The present study was conducted under low soil P condition to assess the genetic variability for yield and its attributing traits in rice genotypes. The experimental material consists of 245 rice genotypes along with six checks which were planted in low P plot at ICAR-IIRR, Hyderabad using augmented block design and phenotyped for the traits viz., days to 50% flowering, plant height, total number of tillers, number of productive tillers per plant, panicle length, single plant yield, thousand grain weight and spikelet fertility. ANOVA analysis revealed that MSS due to test genotypes were significant (p<0.01) for all the traits under study. PCV and GCV were found to be high for single plant yield, total number of tillers and number of productive tillers while, plant height, thousand grain weight and spikelet fertility showed moderate PCV and GCV. Genetic advance as percentage of mean coupled with heritability was observed to be higher for all the traits except panicle length, which was moderate in nature. These results signify that there was sufficient amount of genetic variability for all the studied traits under low P in the studied genotypes. Therefore, genetic improvement through selection for these traits would be more rewarding and could be useful for developing genotypes tolerant to low P stress.