Estimation of Combining Ability in Early Genotypes of Pigeonpea [Cajanus cajan (L.) Millsp.]
Kamal Kumar Sharma *
Department of Genetics and Plant Breeding, College of Agriculture, Ummedganj-Kota, Rajasthan-324001, India.
S. C. Sharma
Department of Genetics and Plant Breeding, Agriculture Research Station, Ummedganj-Kota, Rajasthan-325001, India.
Preeti Verma
Department of Genetics and Plant Breeding, Agriculture Research Station, Ummedganj-Kota, Rajasthan-325001, India.
Hitesh Kumar Koli
MPUAT, Udaipur, Rajasthan-313001, India.
*Author to whom correspondence should be addressed.
Abstract
The present investigation was conducted to estimate general combining ability (GCA), specific combining ability (SCA) and the nature of gene action for yield and associated traits in early pigeonpea genotypes [Cajanus cajan (L.) Millsp.]. Eight genotypes, namely ICPL-20338, ICPL-20340, ICPL-87, Pusa-991, Pusa-992, PA-16, PA-291 and AL-882, were crossed using a diallel mating design during Kharif 2022–23. A total of 36 entries, comprising eight parents and 28 F₁ crosses, were evaluated in a randomised block design with three replications during Kharif 2023–24 at the AICRP on Pigeonpea, Agricultural Research Station, Kota, Rajasthan. Observations were recorded for days to 50% flowering, days to maturity, plant height, primary branches per plant, number of pods per plant, pod length, number of seeds per pod, 100-seed weight, biological yield per plant, seed yield per plant, harvest index, protein content and carbohydrate content. Analysis of variance for combining ability showed significant GCA effects for all traits except pod length, whereas SCA effects were significant for all traits. The ratio of GCA variance to SCA variance was less than unity for all traits, indicating the predominance of non-additive gene action. Among the parents, ICPL-20338, ICPL-20340, ICPL-87 and Pusa-992 were identified as good general combiners for seed yield per plant and related traits. The crosses ICPL-87 × PA-16, ICPL-20340 × AL-882, Pusa-992 × PA-16, ICPL-20338 × AL-882 and ICPL-20338 × PA-291 showed desirable SCA effects for seed yield and important yield-attributing traits. The cross ICPL-20338 × ICPL-87 exhibited significant SCA effects for protein content and carbohydrate content. These parents and cross combinations may be useful in pigeonpea breeding programmes aimed at improving yield and associated traits.
Keywords: Cajanus cajan, general combining ability, specific combining ability, diallel mating, non-additive gene action, hybrid vigour, seed yield, biochemical traits, early genotypes