Genetic Variability Studies on Twelve Genotypes of Rice (Oryza sativa L.) for Growth and Yield Performance in South Eastern Nigeria

Abstract

Twelve genotypes of rice collected from the National Cereals Research Institute (NCRI), Badeggi, Bida, Niger State, Nigeria were evaluated to estimate the magnitude of genetic variability and relationship of some agronomic traits of rice and their contributions to yield. The results obtained showed a significant difference (p ≤ 0.05) among the genotypes in all the traits studied. Genotype ‘WAB 35-1-FX2’ produced a significantly higher grain yield of 3.40 t/ha compared with all the other genotypes in the two years combined. Genotypes ‘WAB 33-25’, ‘WAB 56-1-FX2’, ‘WAB 56-39’, ‘WAB 56-125’, ‘ITA 150’ and ‘FAROX 16 (LC)’ were the most stable grain yielding genotypes across the two years of the experiment. High broad sense heritability (h2bs) was associated with grain yield (h2bs = 98.63%), number of spikelets/panicle (98.78%), plant height (98.34%) for the first year planting, whereas in the second year planting, days to 50% flowering (96.72%), days to maturity (94.14%) and grain yield (83.33%) were among the traits that showed high broad sense heritability. The two years combined correlation analysis showed that grain yield correlated significantly and positively with number of spikelets/panicle (r = 0.2358*), number of panicles/m2 (r = 0.1895*), number of fertile spikelets/panicle (r = 0.1672*) and 1,000 grain weight (r = 0.1247*), indicating that these traits can be phenotypic basis for improving grain yield of rice. Conversely, grain yield exhibited negative correlation with days to 50% flowering (-0.3009) and days to maturity (-0.2650), though not significant. This suggests that rice grain yield can be improved by selecting early flowering and maturing genotypes especially under heat and drought prone conditions.