Diallel Analysis for Productivity and Some Quality Traits in Spring Wheat (Triticum Aestivum L.)

Abstract

Present investigation entitled "Diallel analysis for productivity and some quality traits in spring wheat (Triticum aestivum L.)" was carried out in the Department of Genetics and Plant Breeding, Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, during 2011-12. In this study 10 genotypes namely MP 1236, PBW 550, WH 1094, PBW 590, PBW 373, RAJ 3765, DBW 58, HD 2687, DBW 17 and WH 711 were crossed in diallel fashion (10x10) excluding reciprocals, to study gene action, combining ability variances and effects, manifestation of heterosis, extent of coefficient of variation, heritability and genetic advance, correlation and path analysis. The observations were recorded on 15 traits viz; days to 50% flowering, days to maturity, number of productive tillers/plant, plant height, flag leaf area, spike length, spikelets/ spike, grains/ spike, 1000- grain weight, biological yield/ plant, grain yield/ plant, harvest index, ash content, gluten content and phenol colour reaction. The experiment was planted in Randomized Complete Block Design in three replications with 1 0 parents and 45 F 1's. "F" test revealed significant variance for all the characters. The analysis of genetic components showed that significant additive ( b) and dominant ( H 1 and H 2 ) components were also ~ found highly significant for all the traits. The value of F were positive and significant for days to 50% flowering, plant height, spikelets/ spike, grains/ spike, grain yield/ plant, harvest index and ash content in F1 crosses, indicated the excess of dominant and positive genes in the parents. The environmental component "E" was found non-significant for all the traits. The estimates of h2 were found to highly significant for number of productive tillers/ plant, flag leaf area, spike length, spikeletes/ spike~ biological yield/ plant, grain yield/ plant, harvest index, ash content and gluten content, which indicated that the presence of dominance in F15• Non significant values was reported for rest the traits which indicated that there was partial dominace. The mean of dominance (A, I b t 2 indicated over dominance for number of productive tillers/ plant, flag leaf area, spike length, spikeletes/ spike, grains/ spike, biological yield/ plant, harvest index, ash content and gluten content, while the mean of dominance indicated partial dominance for days to 50% flowering, days to maturity, plant height, 1 000-grain weight and grain yield/ plant. The value of ( H2 /4 H1) was less than 0.25 for all the traits indicating the asymmetrical distribution of positive and negative alleles among the parents. The proportion of dominant and recessive alleles was recorded more than one for 12 characters which indicated dominant alleles were present in the parents for these traits, while this ratio was less than unity for tWo traits, biological yield/ plant and gluten content. The ratio of h 2 I H2 was more than one for 8 traits in F1 generation, which indicated that more than one major gene 0 • A 2 A group was responsible for controlling these traits. However for rest of the tra1ts, the rat1o of h I H2 was less than unity indicated the present of at least one major gene group controlling these traits. The analysis of variance for combining revealed that the variance due to gca and sea were highly significant for all the characters indicated that both the additive and non-additive gene actions were involved in the expression of the traits. The genotypes WH 1094, PBW 590 and PBW 373 were considered as the best general combiners, while hybrids DBW58xDBW17, PBW550xPBW373, MP1236xPBW373, WH1094xPBW590, PBW590xPBW373, RAJ3765xHD 2687, PBW590xWH711, MP1236xPBW550, RAJ3765xDBW58, HD 2687xWH711 and MP1236xWH1094 as good specific combinations for grain yield/ plant and other yield contributing and quality traits. The maximum values of pcv and gcv were recorded for flag leaf area, while the minimum for days to maturity. High heritability coupled with high genetic advance was observed for flag leaf area, grain yield/ plant and biological yield/ plant. The high heritability coupled with moderate genetic advance for grains/ spike, number of productive tillers/ plant, plant height, ash content and spike length were recorded while for traits like 1 000-grain weight, days to 50% flowering, gluten content, spikelets per spike and days to maturity high heritability coupled with low genetic advance was observed. Grain yield/ plant showed highly significant and positive association with number of productive tillers/ plant, plant height, flag leaf area, spike length, grains/ spike, 1 000-grain weight, biological yield/ plant and harvest index. Path coefficient analysis revealed that biological yield had displayed high order of direct effect on grain yield/ plant followed by harvest index, 1000 grain weight, flag leaf area, spike length, grains/ spike, days to 50% flowering and number of productive tillers/ plant, where as days to 50% flowering showed maximum direct effect on gluten content followed by biological yield/ plant, numb~r of productive tillers/ plant, harvest index, flag leaf area, days to maturity, spikelets/ spike, ash content and 1 000-grain weight. Five crosses which showed highest value of heterosis for grain yield were, DBW58xDBW17 (34.19) followed by MP1236xPBW550 (25.88), PBW550xPBW590 (24.02), PBW550xHD2687 (21.19) and WH1094xPBW590 (20.97) which may be exploited for developing hybrids with better yield and quality in wheat. The crosses PBW550xPBW373, MP1236xPBW 373, WH1094xPBW590, MP1236xPBW550~ and RAJ3765xDBW58 which showed good sea effects for yield and 6-8 yield components were also found superior for gluten content, ash content and showed low reaction of phenol on the grains, may be exploited for better yield and chapati quality either by exploiting them through heterosis breeding or involving them in multiple cross breeding programme for obtaining transgressive segregants and broad genetic base population in wheat. On the basis of computed genetic parameters, to exploit additive and non-additive type of gene action, pedigree selection and hybridization among better genotypes has been suggested. Breeding method such as biparental mating followed by reciprocal recurrent selection, triple test cross was suggested for exploiting additive and non-additive type of gene action. Multiple gene input into a central gene pool may be useful to obtain more favourable genes, by involving promising parental lines in eros ing programme.