Genetic variability, heritability and interrelationship in salt-tolerant lines of T. Aman rice

Twenty salt-tolerant breeding lines of T. Aman rice were studied under field conditions at the experimental farm of the Department of Genetics and Plant Breeding, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh. The experiment was conducted following Randomized Complete Block Design (RCBD) with three replications to estimate the genetic variations in yield and yield-related traits, and their interrelationship and to assess the direct and indirect effects of different yield-related traits on grain yield for the selection of high-yielding T. Aman rice. Twelve characters viz., days to flowering, days to maturity, plant height (cm), tillers per hill, panicles per hill, flag leaf length (cm), panicle length (cm), panicle weight (g), filled grains per panicle, spikelet fertility percentage, 100-grain weight (g) and grain yield per m2 (kg) were studied. The genotypes differed significantly for all the traits studied indicating the wide range of variations existed across the genotypes. The analysis of variance of all characters studied was highly significant that revealed a wide range of variability among the newly developed 20 salt-tolerant genotypes of T. Aman rice. The genotypes BU1, BU4, BU6, BU7, and BU14 had high grain yields and could be directly selected as high-yielding varieties. Based on all genetic parameters, all the traits could significantly improve the grain yield of salt-tolerant lines of T. Aman rice. The correlation coefficient revealed that the genotype selected based on days to flowering, days to maturity, plant height (cm), panicles per hill, flag leaf length (cm), panicle weight (g), filled grains per panicle, and spikelet fertility (%) and 100-grain weight directly would significantly contribute to grain yield of 20 salt-tolerant genotypes of T. Aman rice. However, considering the genotypic correlations and path coefficients, direct selection on the basis of panicles per hill, panicle weight, plant height, flag leaf length, filled grains per panicle, spikelet fertility (%), days to flowering, and days to maturity would significantly improve the grain yield of salt-tolerant T. Aman rice genotypes.