Genetic Analysis of Agronomic Traits in Sorghum Parents and Hybrids Across Diverse Male Sterile Cytoplasms and Varying Soil Moisture Conditions

ABSTRACT The predominance of A 1 cytoplasm in sorghum hybrid breeding has limited the exploitation of alternative cytoplasmic male sterility (CMS) sources such as A 2 , A 3 and A 4 . This study evaluated the combining ability and heterosis of hybrids derived from diverse CMS backgrounds (A 1 , A 2 , A 3 and A 4 ) under both drought and irrigated conditions. A total of 241 F 1 hybrids, 35 parents and 4 checks were assessed for yield and related traits across two seasons and moisture regimes. Significant genotype × environment interactions were observed, highlighting the need for environment‐specific recommendations. Notably, A 1 (ICSA 38, ICSA 55 and ICSA 502), A 2 (ICSA 724) and A 4 (ICSA 758) CMS lines exhibited strong general combining ability (GCA) for grain yield under drought, while several A 1 and A 2 lines performed well under irrigation. Restorer lines Parbhani Shakti and ICSR 13038 produced high‐yielding hybrids across environments, with ICSV 15014 and ICSR 13009 showing universal fertility restoration. Specific combining ability (SCA) and heterosis analyses identified ICSA 675 × ICSR 13038 (A 1 ) and ICSA 724 × ICSV 15014 (A 2 ) as top performers under drought, and ICSA 735 × ICSR 13038 (A 2 ) under irrigation. Mean versus stability analysis revealed G151 and G229 as highly stable hybrids. The results confirm the competitive potential of A 2 CMS as an alternative to A 1 , supporting cytoplasmic diversification for enhanced yield stability and resilience in sorghum breeding programmes.