Heterosis and Combining Ability Studies for Yield and Its Contributing Traits Using Wild-Abortive (WA) Cytoplasmic Male Sterile (CMS) Lines in Rice (Oryza sativa L.)

Abstract

Developing high-yielding rice varieties is paramount. This study explores heterosis (hybrid vigor), the phenomenon where hybrid offspring exhibit superior phenotypic performance compared to their parents. The present study evaluated 20 F1’s derived from five CMS lines and four testers along with their parents, including a standard check, for their combining ability and heterosis concerning grain yield and ten yield-contributing traits. The study was carried out at the Research cum Instructional Farm, Department of Genetics and Plant Breeding, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.), India. The research identified superior general and specific combiners. Among lines, IR 79156A and CRMS 31A were excellent general combiners and among testers, IR 10N134 and IR 14V1020 showed strong general combining ability for grain yield per plant. Significant specific combining ability was observed in the crosses, IR 79156A/IRRI-186 followed by IR 58025A/IR 14V1020, IR 68888A/IR 14A150 and CRMS 32A/IR 10N134 for grain yield. Understanding heterosis, defined by the superior performance of F1 progeny over parents, is crucial for crop improvement. This research evaluated rice hybrids for their yield and their contributing traits. It is observed that CRMS 32A/IR 14V1020, CRMS 31A/IR 14V1020 and CRMS 31A/IRRI-186 consistently matured earlier than their respective parents and the check. Concurrently, IR 79156A/IRRI- 186, IR 58025A/IR 14V1020 and CRMS 31A/IR 10N134 demonstrated notable high heterosis for yield and related characteristics, compared to mid-parent, better-parent and standard check. These promising F1 hybrids serve as critical resources for advancing new rice cultivar development programs. By strategically incorporating these findings, researchers can accelerate the development of hybrids with enhanced grain yield and other crucial agronomic traits. This research, therefore, leads to the development of hybrid rice and their further exploitation as commercial hybrids.