P. Wadikar

Combining Ability and Gene Action for Yield and Component Traits in Green Gram [Vigna radiata (L.) Wilczek] Using Line × Tester Analysis

Background: Green gram (Vigna radiata L.) is an important short-duration pulse crop, and its improvement requires reliable information on parental combining ability and the gene action governing yield-related traits. Aims: The study aims to assess combining ability and gene action for agronomic traits using a line × tester mating design in green gram (Vigna radiata L.). Study Design: Line × tester mating design. Place and Duration of Study: Experimental Farm, Department of Genetics and Plant Breeding, College of Agriculture, Latur, during the summer season of 2025–26. Methodology: A line × tester mating framework comprising three female lines (TAKM-140, PANT-M-5 and SML-668), seven male testers (BMB-2302, BMB-2311, BMB-2314, BMB-2315, BPMR-32, BPMR-48 and BPMR-93) and one standard check variety (BM-2003-2) was used to develop 21 cross combinations. The 21 hybrids, their ten parents and the check variety were evaluated. Field observations were recorded for ten quantitative traits: days to 50% flowering, days to maturity, plant height (cm), number of branches per plant, number of clusters per plant, number of pods per cluster, number of pods per plant, number of seeds per pod, 100-seed weight (g) and seed yield per plant (g). Results: Combining ability analysis identified PANT-M-5 and testers BMB-2314, BMB-2315 and BPMR-32 as effective general combiners for seed yield and earliness. The crosses TAKM-140 × BMB-2302, PANT-M-5 × BPMR-32 and SML-668 × BMB-2311 showed significant positive specific combining ability (SCA) effects for seed yield per plant. Gene action analysis indicated that specific combining ability variance (\(σ^2_{SCA}\)) exceeded general combining ability variance (\(σ^2_{GCA}\)) for all evaluated traits. Furthermore, the variance ratio (\(σ^2_{SCA}\)/\(σ^2_{GCA}\)) was less than unity for all traits. Conclusion: The findings indicated a predominance of non-additive gene action in the inheritance of the evaluated agronomic traits. Breeding approaches such as biparental mating or recurrent selection in early segregating generations may therefore be used to exploit this non-additive variance for crop improvement.

Genetic Analysis of Seed Yield and Component Traits through Line × Tester Analysis in Linseed

Aims: The study aims to identify the best general and specific combiners for seed yield and associated traits, and to determine the nature of gene action governing these traits in linseed (Linum usitatissimum L.) through a Line × Tester analysis. Study Design: Line × Tester mating design. Place and Duration of Study: Oilseeds Research Station, Latur, under Vasantrao Naik Marathwada Krishi Vidyapeeth (VNMKV), Parbhani, Maharashtra, India, during the 2025–26 rabi season. Methodology: Forty-two F₁ hybrids developed using seven lines and six testers, together with their parents and a standard check, were evaluated for ten quantitative traits. Combining ability analysis was performed to estimate general combining ability (GCA), specific combining ability (SCA), and the nature of gene action. Results: Analysis of variance revealed highly significant differences among the experimental genotypes for all ten traits, indicating substantial genetic variability. Significant variation due to lines, testers, and line × tester interactions suggested the involvement of both additive and non-additive gene effects. RLC-206 and NL-421 were identified as good general combiners, whereas SLS-145 was the best general combiner among the testers for seed yield. The crosses RLC-148 × RLC-198, RLC-206 × RLC-213, and RL-18123 × SLS-156 exhibited significant positive SCA effects for seed yield per plant. For all traits, SCA variance exceeded GCA variance, indicating the predominance of non-additive gene action. Conclusion: The superior parents and cross combinations identified in the present investigation represent valuable genetic resources for developing high-yielding linseed cultivars. The predominance of non-additive gene action for all the traits studied suggests that breeding approaches such as heterosis breeding, recurrent selection, or biparental mating followed by selection may be effective for improving seed yield and its component traits in linseed.

Assessment of Combining Ability and Gene Action for Yield and Yield-contributing Traits in Sunflower (Helianthus annuus L.)

Aims: To evaluate combining ability, determine the nature of gene action governing yield and yield-contributing traits, and identify superior parents and promising hybrid combinations in sunflower (Helianthus annuus L.). Study Design: Line × tester mating design. Place and Duration of Study: Oilseeds Research Station, Latur, Maharashtra, India, during kharif 2025 (hybrid development) and rabi 2025–26 (field evaluation). Methodology: Six cytoplasmic male-sterile (CMS) lines and seven restorer lines were crossed in a line × tester mating design to generate 42 hybrids. The resulting hybrids, together with their 13 parents and three standard checks, were evaluated in a randomised block design with two replications for ten agro-morphological and quality traits. The data were subjected to analysis of variance, line × tester analysis to estimate general and specific combining ability, and assessment of gene action following Kempthorne (1957). Results: Significant variation was observed among the 58 genotypes for all ten traits studied, indicating sufficient genetic variability for effective selection and hybrid development. Combining ability analysis revealed significant GCA and SCA effects for most traits, with SCA variance exceeding GCA variance and indicating the predominance of non-additive gene action. CMS-249A and CMS-47A exhibited desirable GCA effects for several yield-related traits, whereas EC-601924 and EC-601751 were superior restorers. The hybrid combinations DSP-11A × EC-601924, CMS-249A × RHAGPR-3, and CMS-10A × EC-601751 expressed high SCA effects together with desirable performance for yield and related traits, indicating their suitability for hybrid breeding. Conclusion: Both additive and non-additive genetic effects contributed to the inheritance of yield and yield-contributing traits, although non-additive gene action was predominant. The identified superior parents and hybrids may be utilised in sunflower hybrid-breeding programmes to develop high-yielding hybrids.

Estimation of Trait Association and Path Analysis for Yield and Yield Contributing Characters in Sesame (Sesamum indicum L.)

Sesame (Sesamum indicum L.) is a valuable oilseed crop, and effective improvement of seed yield requires an understanding of the relationships among yield-contributing traits. This study assessed genotypic and phenotypic correlations and path coefficients for seed yield and nine contributing traits in 30 sesame genotypes. The experiment was conducted under irrigated conditions at the College of Agriculture, Latur, during summer 2025–26 using a randomised block design with two replications. Data were recorded for days to 50% flowering, days to maturity, plant height, number of branches per plant, number of capsules per plant, capsule length, number of seeds per capsule, 1000-seed weight, oil content, and seed yield per plant. Analysis of variance indicated significant differences among the genotypes for all ten traits. Seed yield per plant showed significant positive correlations with 1000-seed weight, number of seeds per capsule, number of capsules per plant, and plant height at both genotypic and phenotypic levels. Path analysis showed that 1000-seed weight had the largest positive direct effect on seed yield, followed by number of seeds per capsule and number of capsules per plant. Plant height contributed mainly through indirect effects involving these yield components. The findings indicate that 1000-seed weight, number of seeds per capsule, and number of capsules per plant may serve as useful selection criteria for improving seed yield in the evaluated germplasm. Validation across seasons and environments is required before these traits are adopted as stable breeding criteria.

Multi-trait model-based assessment of selection efficiency and stability in soybean germplasm.

Genetic Analysis of Yield and Associated Traits through Combining Ability and Gene Action in Sunflower (Helianthus annuus L.)

Aims: To evaluate the combining ability, determine the nature of gene action governing yield, oil content and associated traits, and identify superior parents and promising hybrid combinations for sunflower (Helianthus annuus L.) improvement. Study Design:  Line × tester mating design. Place and Duration of Study: Oilseeds Research Station, Latur, Maharashtra, India, during kharif 2025 (hybrid development) and rabi 2025–26 (field evaluation). Methodology: Six cytoplasmic male sterile (CMS) lines and seven restorer lines were crossed in a line × tester mating design to generate 42 hybrids. The resulting hybrids, along with their 13 parents and three standard checks, were evaluated in a randomised block design with two replications for ten agro-morphological and quality traits. Data were subjected to analysis of variance, line × tester analysis to estimate general and specific combining ability, and assessment of gene action following the method of Kempthorne (1957). Results: Analysis of variance revealed highly significant differences among the genotypes for all the traits studied, indicating substantial genetic variability. Line × tester analysis showed significant GCA and SCA effects for most traits, with non-additive gene action predominating for seed yield and several associated traits. Among the parents, NDCMS 2A and CMS 597A were identified as good general combiners among the lines, while NDL20, NDL3 and GMU847 were the most desirable testers for seed yield, oil content and associated traits. The crosses NDCMS 2A × NDL20, CMS 597A × NDL20, CMS 597A × NDL3, CMS 852A × GMU847 and CMS 597A × HOCL-20R exhibited desirable specific combining ability effects coupled with superior per se performance, indicating their potential for exploitation in sunflower hybrid breeding. Conclusion: The findings indicated the involvement of both additive and non-additive gene action in the inheritance of yield, oil content and associated traits in sunflower, with the predominance of non-additive gene action for most of the characters. The identified superior combiners and promising hybrid combinations provide valuable genetic resources for the development of high-yielding and high-oil sunflower hybrids and can be effectively utilised in future sunflower breeding programmes.

Genetic Variability, Trait Association and Path Analysis for Yield and Yield-Contributing Traits in Linseed (Linum usitatissimum L.)

Linseed (Linum usitatissimum L.) is an important oilseed crop in which improvement of seed yield depends on the availability of genetic variability and the identification of useful yield-associated traits. The present investigation was undertaken to assess genetic variability, heritability, genetic advance, correlation and path relationships for ten quantitative traits in 40 linseed genotypes. The experiment was conducted during rabi 2024–2025 at the College of Agriculture, Latur, Maharashtra, India, in a randomised block design with two replications.  The traits evaluated included days to 50% flowering, days to maturity, plant height, number of branches per plant, number of capsules per plant, number of seeds per capsule, 1000-seed weight, oil content, harvest index, and seed yield per plant. Analysis of variance revealed significant differences among the genotypes for all the assessed traits.The recalculated estimates showed that GCV ranged from 4.61% for days to maturity to 22.15% for number of branches per plant, while PCV ranged from 5.14% for harvest index to 22.53% for number of branches per plant. Broad-sense heritability ranged from 63.06% for days to maturity to 98.24% for harvest index. Genetic advance as a percentage of the mean was highest for number of branches per plant (44.86%), followed by oil content (35.74%), 1000-seed weight (28.49%), number of capsules per plant (26.80%), number of seeds per capsule (26.16%) and seed yield per plant (25.96%). At the genotypic level, seed yield showed positive associations with number of branches per plant (0.7118), number of capsules per plant (0.7044), number of seeds per capsule (0.7265), plant height (0.0073) and 1000-seed weight (0.0141). The reported path analysis indicated positive direct effects of number of seeds per capsule (0.8083) and number of capsules per plant (0.3397) at the genotypic level, while number of branches per plant showed a high positive direct effect at the phenotypic level (1.6152). Thus, number of branches per plant, number of capsules per plant and number of seeds per capsule may be considered important selection criteria for improving seed yield under the present experimental conditions. The study was conducted at one location in one season; therefore, further multi-location and multi-season evaluation is necessary.