GENETIC VARIANVCE AND BREEDING POTENTIAL OF RESTORER LINES IN PHILIPPINE RICE (Oryza sativa ) GERMPLASM

摘要

The genetic variability of restorer germplasm in the Philippines for the development of three-line rice hybrids were determined by developing half-sib hybrids following the line x tester mating design involving 20 randomly selected restorer lines andthree commercially usable CMS lines, evaluated in two environments (Munoz, Nueva Ecija and Los Banos, Laguna). Analysis of variance for both locations revealed highly significant (P<0.01) differences among restorer lines, CMS lines, and restorer line x CMS line interactions for all traits. Estimates of genetic variance of restorer lines for days to 50% flowering, plant height (cm), grain yield ha~(-1), panicle length (cm); number of spikelets panicle~(-1), percent filled grains, and 1000-grain weight (g) were highly significant but not for number of productive tillers. Confidence interval estimates for all traits were also significantly different from zero, except for number of productive tillers, indicating substantial genetic variability for these traits. Combined mean performance across locations revealed several hybrids out-yielding the best check varieties. Twenty-five percent (15/60) of hybrids evaluated at Los Banos exhibited 16.73-4.29% yield advantage over the highest yielding check, PSB Rc72H. At Munoz, three hybrids (5%) out-yielded the highest yielding check PSB Rc28. Restorer lines contributed the most to total variation except for tiller number, days to maturity, and spikelet number. The wide range of genetic variability revealed in thePhilRice restorer germplasm could be exploited to generate outstanding hybrids for commercial cultivation.