Studies on some genetic parameters of rice (Oryza sativa L.)

Summary In order to utilize the available useful variation in breeding rice to improve yield and quality of grain, the performance of a wide range of rice germ plasm comprising 30 varieties was evaluated in northern India, a major rice growing belt. Plant performance revealed high genetic divergence and phenotypic variability in the crop, with the maximum range of variation being for grain number per panicle and the minimum for grain dimensions. There were also significant differences among varietal means for ten phenotypic traits. Genotypic and phenotypic variance contributed profoundly to the variance of the phenotypic traits studied, but, since genetic variability in the traits related to yield was considerable, there is scope for further improvement in yielding ability. Grain number per panicle, number of effective tillers per plant and culm length exhibit high heritability, and genotypic coefficient of variation and therefore a high genetic advance. Thus, selection for these traits would be effective in crop improvement. Moreover, grain number per panicle shows a significant positive correlation with yield, and this trait could profitably form a reliable index for the yielding capacity of this crop.