Genetic Assessments of Some Morphological Traits in Rice by Generation Mean Analysis

To study the nature and magnitude of gene effects, heritability and number of effective factors for grain yield and some yield components in rice, six generations viz., P1, P2, F1, F2, BC1 and BC2 were prepared from the crosses of Shapasand × IRFAON-215 and IRFAON-215 × Saleh and grown in a randomized complete design with three replications. Results of analysis of variance showed significant differences between generations for all traits. Significant heterosis was observed for grain yield, plant height, and panicle length and 100-grain weight. Additive (a) gene actions were important in controlling of grain width, length and shape in the first cross (SH × IR) and grain length in the second cross (IR × SA). 100-grain weight, plant height and grain yield in the first cross and grain width and shape, 100-grain weight, days to flowering and grain yield in the second cross were influenced by dominance (d) gene actions and epistatic effects. Degree of dominance revealed over-dominance for grain length and shape, 100-grain weight and grain yield in SH × IR and for grain shape and 100-grain weight in IR × SA. For the rest of traits partial dominance was revealed. For yield and those yield components that were influenced by non-additive gene action, exploiting of heterosis are suggested for improving rice yield using breeding materials of this research.