Dissecting gene action for heat stress-responsive traits in chickpea (Cicer arietinum L.) across heat stress environments

Limited information is available in the literature on the dissection of non-additive gene action under contrasting sowing environments, leaving a gap in breeding strategies for heat-tolerant chickpea varieties. Therefore, an investigation was carried out on the gene interactions influencing physio-biochemical traits in chickpea (Cicerarietinum L.) under heat stress conditions. Three chickpea crosses, namely, RSG807 x RSG895, RSG895 x HC5, and RSG974 x Avrodhi, were evaluated under two sowing environments during rabi seasons of 2019–20 to 2021–22. Genetic analysis revealed the presence of duplicate epistasis for several traits in specific cross-environment combinations. Relative water content in RSG-974 x Avrodhi under late sowing (E2); membrane stability index in RSG-807 x RSG-895 under E2; total chlorophyll content in RSG-807 x RSG-895 under timely sowing (E1), RSG-974 x Avrodhi under E2, and RSG-895 x HC-5 under both E1 and E2; proline content in RSG-974 x Avrodhi under E1; protein content in RSG-807 x RSG-895 and RSG-974 x Avrodhi under E2; and seed yield per plant in RSG-895 x HC-5 under E1 were observed. Overall, the inheritance of most physio-biochemical traits across both sowing environments was predominantly governed by non-additive gene actions.