Author(s): S.S. NAGAR, P. KUMAR, G. SINGH, V. GUPTA, CHARAN SINGH AND B S TYAGI

Abstract: A study was conducted for the assessment of gene action involved in the expression of different yield components in bread wheat by using the Hayman’s graphical approach. The significant additive variance (D) and dominance variance (H1) indicated that, expression of these traits is controlled by both additive and non-additive gene action. Among the parents, there was asymmetrical distribution of positive and negative dominant genes and preponderance of over-dominance type of gene action for all the studied traits in both F1 and F2 generations. Graphical regression analysis for days to 50% flowering, days to maturity, plant height, effective tillers plant-1, grain number spike-1, 1000-grain weight and grain yield showed negative intercepts of Wr-Vr regression line, indicating over-dominance type of gene action, therefore selection should be delayed to later generations for these traits. The cultivar DBW 14 for grain yield and NW 2036 for days to 50% flowering, days to maturity, plant height and effective tillers plant-1 contain maximum dominant genes in both F1 and F2 generations, therefore these cultivars could be used as donors in wheat breeding programme. Based on the specific combining ability effects the cross PBW343 × K8962 identified to be a superior candidate for 1000- grain weight and grain yield in F1 generation. Therefore, it is suggested that present findings may be useful in formulating future breeding programme to develop high yielding wheat genotypes.

DOI: 10.22271/09746315.2020.v16.i1.1269

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