GENE ACTION AND COMBINING ABILITY ANALYSIS FOR YIELD AND YIELD ATTRIBUTES IN RICE (ORYZA SATIVA L.)

Sharda Prasad
Department of Genetics and Plant Breeding, Narendra Deva University of Agriculture and Technology
April, 2014
 

Abstract
The present study was conducted to determine the gene action and combining ability analysis for yield and yield attributes in rice (Oryza sativa L.). The present study was carried out during kharif, 2013, at the Genetics and Plant Breeding farm of Narendra Deva University of Agriculture and Technology, Narendra Nagar, (kumarganj) Faizabad (U.P.) The experiment was based on evaluation of a line x tester set of 36 hybrids (F1’s) and their 15 parents along with 2 checks, for thirteen characters under normal sown and irrigated condition in randomized block design with three replications during Kharif, 2013. The 36 F1’s were generated by crossing 3 testers with 12 lines during Kharif, 20012. The observations were recorded on days to 50% flowering, flag leaf area (cm2), panicle length (cm), plant height (cm), panicle bearing tillers plant-1, spikelets panicle-1, spikelet fertility (%),biological yield plant-1 (g), grain yield plant-1(g), harvest index (%), test weight (g), L/ B ratio, and chlorophyll content (spad value). The analysis of variance for treatments, parents and crosses was highly significant for all the traits indicating the existence of sufficient variability in the treatments, parents and crosses for all the traits. The variation due to parent’s vs crosses was significant for all traits except parent’s vs crosses for L/B ratio, that indicating the presence of heterosis in the crosses. The dominance variance > additive variance, degree of dominance >1 except days to 50% flowering, spikelets panicle-1 and L/B Ratio, indicating selection is ineffective as it is non fixable; and general predictability ratio less than one for all the character the, indicating the involvement of non-additive gene action and heterosis was mainly governed by over dominance for majority of the traits. The non-significance of mean squares due to testers (males) for all the characters except days to 50% flowering and L/B ratio and lines (females) significant for panicle length, spikelets panicle-1 and test weight except all the character indicated non-significant prevalence of additive effects in expression of the related traits. The significance of mean squares due to lines × testers for all the traits provides a direct test indicating that (i) non-additive variance was important for all of the characters; and (ii) combining ability contributed heavily in the expression of these traits. In general, maximum contribution to the total variance was due to females higher than due to males for all the traits except days to 50% flowering and L/B ratio. Among the parents, best five genotypes were IR55179-3B-11-3, IR 11T159, Jaya, IR 58025 B and NDRK 50026 exhibited significant GCA effects, for grain yield plant-1, indicating the involvement of additive gene action for yield and component traits. Among the crosses, best five hybrids were Narendra Usar Dhan 2009 x NDRK 50026, Jaya x Narendra Usar Dhan 2008, IR11T164 x Narendra Usar Dhan 2008, CSR 28 x NDRK 50026 and Jaya x Narendra Usar Dhan 3 exhibited significant SCA effects for grain yield plant-1, indicating the preponderance of non-additive gene action for yield and component. Majority of the desirable heterotic cross combinations possessed at least one of the high general combiner. IR55179-3B-11-3, IR 11T159 and Jaya were found to be the best parental lines based on per se performance and GCA effects for grain yield plant-1 which may be utilized as a donor in hybridization programme. arendra Usar Dhan 2009 x NDRK 50026 and Jaya x Narendra Usar Dhan 2008 were found to be best crosses based on per se performance and sca effects for grain yield plant-1, indicated the exploitation of heterosis to enhance yield potential.