Physio-biochemical trait characterization using generation mean analysis in chickpea (Cicer arietinum L.) under timely and late sown conditions

Limited information is available regarding the interaction effects, particularly for physio-biochemical traits under heat stress conditions in chickpeas, which are critical for identifying heat-tolerant genotypes. To address this gap, a field experiment was conducted to study gene effects for various physio-biochemical traits of four specific crosses, namely, RSG-973 × HC-5, RSG-963 × RSG-973, CSJD-884 × Avrodhi and RSG-974 × CSJ-515 during the rabi seasons of 2019–20 to 2021–20 under two sowing environments. Results revealed duplicate epistasis for specific traits observed in different cross-environment combinations, such as membrane stability index in RSG-973 × HC-5 under E2 and in CSJD-884 × Avrodhi under both E1 and E2, total chlorophyll content in RSG-973 × HC-5 under E2, carotenoid content in RSG-974 × CSJ-515 under E2, proline content in RSG-974 × CSJ-515 under E1, protein content in RSG-973 × HC-5 under E1, and seed yield per plant in CSJD-884 × Avrodhi under E2. The predominance of additive (d) and/or additive × additive ‘i’ gene effects, along with significant contributions of non-additive gene effects (h and/or j and/or l), for protein content in RSG-973 × HC-5 under E2 condition. Overall, non-additive gene effects (h, j, and l) were predominant for most traits across the studied crosses under both timely and late-sown conditions.