Genetic Analysis of Some Cytoplasmic Male Sterile and Suggested Restorer Rice Lines

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OUR CYTOPLASMIC Male Sterile rice (CMS) lines having diverse cytoplasmic source and ten suggested restorers beside their forty F1 rice hybrids were the materials of this study. The aim of this investigation was to study the genetic variance components, heritability and combining ability analysis in relation identifying desirable parents and hybrid for hybrid rice breeding program. The additive variance (σ²A) and the relative importance of GCA were higher for 1000-grain weight, number of panicles/ plant, number of spikelets/ panicle and heading date while the opposite was true in the rest characters. The CMS lines D297A and G46A and the restorers Wita12, Giza178 and Giza182 were the best combiners for grain yield. Yimi 15A was the best combiner for earliness. According the scale of Wang (1981) of arrangement the parent materials, G46A ranked first (compared with the other CMS lines) while wita 12 was the best combiner among all suggested restorers. Grain yield, fertility percentage and number of spikelet/ panicle recorded the highest estimates of genotypic coefficient of variability. Heritability estimates in narrow sense was relatively high for 1000-grain weight and heading date. Fertility percentage, grain yield and number of filled grain/ panicle recorded relatively higher values for the expected genetic advance from selection (Δg %). D297A x Wita 4, G46A x Giza 181 and G46A x Giza 182 rice hybrids were distinguished combiners for grain yield and most of its components, indicating that these hybrids and their parents beside Wita12 and Giza 178 may be involved in the hybrid rice breeding program for grain yield improvment.