Combining ability analysis of groundnut ( Arachis hypogaea L.) genotypes for yield and related traits under drought-stressed and non-stressed conditions

Genetic advancement and gains in yield and related traits are dependent on the selection of best combiner parents and progenies under the prevailing growing conditions. This study was conducted to determine the combining ability effects of eight selected drought-tolerant groundnut parental lines and their F2 progenies under drought-stressed (DS) and non-stressed (NS) conditions to determine the gene actions involved in the inheritance of the studied traits and identify the best parents and progenies for further improvement of the crop for moisture stress tolerance. Experiments were conducted at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in India during 2020 cropping season. Data on some of the important physiological, yield and yield component traits were collected. The general combining ability (GCA) effects of parents were significant ( P < 0.05) for all assessed traits under all testing conditions, except for PB under DS and NS conditions in the glasshouse. The specific combining ability (SCA) effects of progenies were significant ( P < 0.05) for all traits, except for PH across all testing environments and PB under field conditions. The genotype ICGV 10178 was the best general combiner with positive contribution and significance to SCMR, PY, SHP, KY, TBM and HI and reduced SLA. Crosses ICGV 10178 × ICGV 11369, ICGV 10373 × ICGV 15083, ICGV 98412 × ICGV 15094 and ICGV 10178 × ICGV 98412 were the best specific combiners for enhanced pod yield and drought tolerance. The GCA was found predominant over the SCA effect for the inheritance of PY, KY and TBM. Higher GCA: SCA rations were recorded for PY and KY under both DS and NS conditions, and SCMR, SLA and TBM under DS condition suggesting the predominant role of additive genes conditioning the inheritance of these traits. Therefore, the above new progenies are useful populations for developing improved pure line groundnut varieties with high pod yield and drought tolerance.