RÉSUMÉ
The present experiment was conducted to study the variability, heritability and genetic advance in F2 segregating population derived from the cross, RNR-15048 x Dokra-Dokri, evaluated in augmented design with two checks at ICAR-IIRR, Hyderabad during the Kharif-2022. Analysis of variance revealed the presence of significant differences for all eleven traits examined, indicating the presence of genetic variation between the individuals studied. Higher values of Genotypic Coefficient of Variation (GCV) and Phenotypic Coefficient of Variation (PCV) were observed for panicle weight, number of filled grains, number of unfilled grains, total grains per panicle, and single plant yield. Least difference was observed between PCV and GCV value for almost all the traits indicating the little influence by the environment and possibility for genetic improvement of these traits through selection. The traits plant height, panicle weight, number of filled grains, number of unfilled grains, total grains per panicle, spikelet fertility, thousand grain weight and single plant yield recorded high heritability (>60%) associated with high genetic advance as percent of mean (>20) resulting in no environmental influence on the expression and selection for improvement of such characters could be worthwhile. High heritability coupled with moderate genetic advance as percent of mean was observed for panicle length propounding non-additive gene action in their inheritance suggesting heterosis breeding could be useful for improving these traits. Overall high PCV and GCV coupled with high heritability and high genetic advance as percent of mean was noticed for panicle weight, number of filled grains, number of unfilled grains, total grains per panicle, and single plant yield suggesting significant amount of variability with predominance of additive type of gene action. Hence, direct phenotypic selection.
RÉSUMÉ
The existence of genetic variability within a population is a fundamental requirement for promoting the effectiveness of any breeding operation. The study was carried out at Dr. RPCAU's research farm located in Pusa Samastipur, Bihar, during the kharif season of 2019-20. The objective was to assess the genetic variability among 23 cowpea genotypes (22 genotypes from various locations in the country and 1 check genotype). The study employed a randomised block design, consisting of three replications and a total of fifteen characters were recorded during the study. The analysis of variance (ANOVA) revealed statistically significant mean sum of squares (MSS) values attributed to genotype for all recorded variables, suggesting the existence of a substantial amount of diversity across the cowpea genotypes utilised in the study. In general, the recorded values for the Phenotypic Coefficient of Variation were found to be higher than those for the Genotypic Coefficient of Variation. The study observed high heritability estimates and high genetic advance for various traits, including plant height, number of leaves per plant, stem thickness, leaf-to-stem ratio, dry matter percentage, leaf fresh weight per plant, dry weight of stem per plant, seed yield per plant, and dry matter yield per plant. These findings suggest that the influence of the environment on these phenotypes is minimal. One of the key conclusions drawn from the study is that the direct selection of these traits can be employed to enhance fodder characteristics in cowpea.
RÉSUMÉ
Genetic variability is a major component which helps in selecting better genotypes under different environmental conditions. Thus, this study was conducted to understand the genetic variability and its components and their trait associations of yield characters from the cross of GKVK-13 and KCG-2 that contribute to the F6 and F7 families. In an augmented block design with three checks, TMV-2, KCG-6, and KCG-2, the study was carried out at the University of Agricultural Sciences, Bangalore, in the 2017 summer and Kharif (rainy seasons). Highly significant differences between the families were found in the analysis of variance for all the characters studied in the F6 and F7 generations, indicating that there is enough variation. Furthermore, medium to high Phenotypic coefficient of variation and Genotypic coefficient of variation values coupled with high heritability and medium to high genetic advance as per cent mean observed in most of the traits showed that the majority of the attributes were controlled by additive gene activity and that there was adequate variability. In addition, phenotypic correlation coefficients depicted significant positive associations for most of the traits studied. The implications of the results are discussed. The study concludes that there was the presence of additive genes controlling most of the traits and early selection of these traits is possible for groundnut improvement in the breeding programme.
RÉSUMÉ
Selection which is the basis of every breeding programme operates only on variation which is of genetic nature. A wide range of variability present in any crop always provides the better chances of selecting desired types. A field experiment was carried out at Vegetable Research Farm, Department of Horticulture, Institute of Agricultural Sciences, Banaras Hindu University during 2012 to evaluate the diverse genotypes of tomato. Analysis of variance indicated highly significant differences among the genotypes for all the characters. The highest GCV and PCV were observed with the character fruit yield per plant followed by number of seeds per fruit. Whereas, the lowest GCV and PCV were recorded by the character days to 50% fruiting followed by days to 50% flowering. The heritability estimates were high for all the characters except number of branches per plant which showed moderate heritability. The maximum heritability was observed for number of seeds per fruit and average fruit weight. High GCV and heritability coupled with high genetic advance was observed for fruit yield per plant followerd by number of seeds per fruit indicating that they are governed by additive genes and could be effectively improved through selection.