Genetics of Some Agronomic and Yield Traits in Rice (Oryza Sativa L.)

Six rice genotypes (FARO20 and FARO52 as female parents and FARO31, FARO39, FARO45 and FARO46 males) were crossed in a line x tester mating fashion to develop eight (8) F1 hybrids. The parents along with the F1 population were evaluated during the off season in 2010 at the screen house of the Institute for Agricultural Research (I. A. R), Samaru in a completely randomized design with three replicates to obtain information on estimates of genetic variations, combining ability and heritability. Data were taken on seedling vigour, plant height, number of tillers, days to 50 % flowering, panicle length, panicle weight, yield per plant and 1000grain-weight. Results from analysis of variance showed highly significant differences among the genotypes for all the traits. This is an indication of the presence of considerable amount of genetic variability in the materials, which could be used to initiate selection for population improvement. Estimates of variance due to GCA and SCA and their ratios revealed preponderance of non-additive gene action for all characters except for days to 50 % flowering. Positive GCA and SCA effects were observed among the lines and testers for yield per plant and other agronomic characters studied. Broad sense heritability estimates were high for all the traits coupled with high genetic advance for yield per plant, 1000grain-weight, panicle weight, number of tillers and plant height, while the lowest genetic advance was observed in panicle length.