Assessment of genetic variability and character association for grain yield and its component traits in bread wheat (Triticum aestivum L.)

Abstract

A study was conducted for estimating genetic variability and characters association for eleven yield components using 169 genotypes (13 parents, 78 F₁ and 78 F₂) of bread wheat through half-diallel mating design during rabi season 2012-13 and 2013-14. The genetic variability, heritability in broad sense, genetic advance, correlation coefficients and path analysis were carried out for the assessment of genotypes through eleven yield component traits namely; days to 50% flowering, days to maturity, plant height, spike length, number of effective tillers per plant, number of grains per spikelet, number of grains per spike, 1000-grain weight, biological yield per plant, harvest index and grain yield per plant. Analysis of variance showed significant differences (at1% level of significance) for all the traits under study in both the generations (F₁ and F₂). The phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) were high for plant height followed by number of effective tillers per plant, biological yield per plant, grain yield per plant, while high heritability coupled with high genetic advance were recorded for plant height and spike length in both F₁ and F₂ generations, respectively. Grain yield per plant was positively and significantly associated with a number of effective tillers per plant, spike length, number of grains per spike, 1000-grain weight, biological yield per plant and harvest index while significantly but negatively associated with plant height. Path analysis revealed that the traits namely biological yield per plant, number of effective tillers per plant, number of grains per spike, plant height and harvest index exhibited positive direct effects on grain yield at both phenotypic and genotypic level in both generation (F₁ and F₂). These results, thereby suggests that yield improvement in breads wheats could be possible by emphasizing these traits while making selections in early generations.