Genetic Architecture and Character Association Analysis for Yield and Some Quality Components in .Spring Wheat (Triticum Aestivum L.)

Abstract

The present investigation was carried out with 15 parents and 44 F1's developed from line x tester mating design. The parental lines (11 lines and 4 testers) were grown during rabi, 2012-2013 and 44 cross combinations among lines and testers were made and the seeds of parental lines and 44 crosses were procured. The parents and F1s were evaluated in a Randomized Completely Block Design in three replications at Crop Research Centre (Chirodi Block) of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut (U.P.) during rabi, 2013-14. The observations were recorded for eighteen quantitative characters viz; days to ear emergence, days to 50% flowering, days to maturity, plant height (em), peduncle length (em), spike length (em), spikelets per spike, productive tillers per plant, grains per spike, flag leaf area ( cm2 ), biological yield per plant (g), grain yield per plant (g), harvest index (%), 1000 grain weight (g), gluten content (%), protein content (%), ash content (%), and phenol colour reaction (grading) and data of these eighteen traits were subjected to statistical and biometrical analysis except for phenol colour reaction, to find out analysis of variance, combining ability variance and effects, estimates of heritability, genetics advance in percent of mean, correlation coefficient, path coefficient and extent of heterosis. Data on phenol colour reaction was recorded in five grades,black, dark brown, light brown, light colour on edge and no colour. Parents and crosses were grouped in these five categories. Analysis ofvariance (ANOVA) revealed that a wide amount of variability among the genotypes were present for all the traits under study. Estimates of phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) for all the traits, but little differences were recorded between ·PCV and corresponding GCV values for all the traits, which indicated that there was not much influence of environment in the expression of the traits, under study. High estimates (>30 %) of heritability in narrow sense were found for characters namely, biological yield per plant, peduncle length, plant height and days to 50 % flowering while, medium estimates of heritability in narrow sense were recorded for eleven characters. High genetic advance in % of mean were found for ash content followed by grain yield per plant, harvest index and flag leaf area. High heritability (narrow sense) coupled with moderate genetic advance in percent of mean were observed for biological yield per plant, peduncle length and plant height and moderate heritability coupled with high genetic advance were recorded for ash content, harvest index and flag leaf area, this indicated that these traits rna~ be relied upon while selecting the genotypes for improvement in wheat. Analysis of v~nance for combining ability revealed that variance gca among female lines was found highly significant for four traits viz; days to 50 % flowering, peduncle length, spike length, a?d . biological yield per plant, and for one trait namely ash content it was found only Slg~lficant, while variance gca among males (testers) was found non-lgnificant for all the traits. However, variance sea among crosses due to interaction between females x males (F1s) was found to be highly significant for all the characters under study. These findings indicated that both the additive and non-additive gene actions played a predominance role in expression of the characters under study hence, appropriate breeding strategies could be adopted such as pedigree selection, heterosis breeding, biparental mating, reciprocal recurrent selection, while making improvement in wheat crop. Parents NW5038, RW346, RAJ4246, HD2824, GW433 and DBW17 were good general combiners for yield and quality traits. These lines may be handled in a cross breeding programme through pedigree selection for better improvement in wheat crop. However, parents, NW5038, GW433 were common good general combiners for grain yield per plant with light colour reaction (at 1 % phenol solution); parents NW5038, RAJ4246, DBW90, RW346 and HD2967 for gluten content; RAJ4246 and UP2565 for protein content; RAJ4246, DBW90 and HD2733 for ash content. These parents could also be involved in crossing programme followed by pedigree selection for improving yield and quality traits and for having broad genetic base in wheat. Cross combinations HD2824 x DBW17, HD2824 x HD2967, NW5038 x HD2967 and HD3095 x HD2733 showed highly significant sea effects along with good per se performance for grain yield per plant, and also for some other important yield and quality components. These cross combinations may be exploited in heterosis breeding programme for better improvement of yield and quality in wheat crop. Cross combinations, HD2824 x DBW17, RW346 x HD2733, HD2824 x HD2967, NW5038 x HD2967, HD3095 x HD2733, HD3095 x DBW17, and GW433 x HD2967 were found superior on the basis of significant sea effect and good per se performance for yield and its components, these combinations could also be exploited in heterosis breeding programme. Crosses HD2824 x DBW17, HD3095 x HD2733 and GW433 x HD2967 were common for grain yield per plant and phenol colour reaction, crosses HD2824 x DBW17, NW5038 x HD2967 and HD3095 x HD2733 were common for grain yield per plant and ash content; crosses HD2824 x HD2967 was common for grain yield per plant, gluten content and protein content; cross HD2824 x DBW J 7 was recorded as common for grain yield per plant, early maturity, ash content and phenol colour reaction; cross NW5038 x HD2967 was recorded as common for grain yield per plant, early maturity and ash content; cross HD3095 x HD2733 was common for grain yield per plant, phenol colour reaction, and ash content (a trait showing approximate picture of mineral matter present in the wheat grain). These cross combinations may be exploited in heterosis breeding programme for better improvement of yield and quality in wheat. Grain yield per plant exhibited highly significant and positive association with harvest index, biological yield per plant, flag leaf area, spikelets per spike and days to maturity. Thus, it can be inferred that by improving these characters either alone or in combination the yield in wheat may be improved. Genotypic and phenotypic path coefficient revealed that harvest index and biological yield per plant had high (0.30 to 1.00) direct effect on grain yield, therefore, direct selection for these two traits would be effective for further yield improvement in wheat genotypes. Genotypic path coefficient revealed that days to ear emergence had very high (> 1) negative direct effect while, days to 50 % flowering had very high (>I) positive and direct effect on protein content, so direct selection of genotypes for protein content through these characters may be effective. Seventeen hybrids were considered as superior F1 hybrids where the significant heterosis(%) over check variety (HD2967) was observed in range of 16.66 % to 44.65 % for grain yield. By exploiting these cross combinations through heterosis breeding programme will lead in development of promising hybrid population for high productivity in wheat.