Assessment of heterosis and inbreeding depression for yield and its component traits in pigeonpea [Cajanus cajan (L.) Millsp.]

Abstract

Pigeonpea [Cajanus cajan (L.) Millsp.] is an important protein-rich pulse crop with multipurpose uses, crucial for food and nutritional security in India. The present study evaluated heterosis and inbreeding depression in four F1 hybrids-Cross I (GT-288A × NPR-10), Cross II (GNP-3A × NPR-20), Cross III (GNP-4A × NPR-21) and Cross IV (GNP-5A × NPR-17) developed using CMS lines and fertility restorer lines. F1 and F2 generations were assessed for ten agronomic traits during Kharif 2024. Significant positive heterosis and heterobeltiosis were observed for pods per plant, seed yield per plant and other yield-related traits, whereas early flowering and maturity exhibited negative heterosis, indicating potential for earliness. Positive inbreeding depression in F2 revealed the breakdown of favourable gene combinations, suggesting non-additive gene action (dominance and epistasis) governing these traits. Among the crosses, GNP-5A × NPR-17 showed the highest heterosis and heterobeltiosis for seed yield and associated traits, highlighting its promise for hybrid development. These findings provide valuable insights into the genetic control of key agronomic traits in pigeonpea and underscore the importance of exploiting heterosis in breeding programs. The findings underscore the importance of exploiting heterosis to develop high-yielding, stable and genetically improved pigeonpea hybrids, contributing to enhanced productivity and sustainability in pulse production.