Chickpea Seeds Developed Under High-Temperature Conditions During Summer Confer Enhanced Drought Tolerance

Chickpea, a predominantly winter-season crop, is highly susceptible to drought stress during its reproductive stage, often resulting in substantial yield losses. To address this challenge, we tested the hypothesis that seeds developed under high-temperature conditions in the summer can enhance drought tolerance in progeny plants. This study evaluated the effects of seed development environment-summer-season seeds (SS) versus normal/winter-season seeds (NS)-on the morphological, physiological, biochemical and yield responses of chickpea under water-deficit stress (WDS). Genotype-specific performance was assessed across two seasons using seeds harvested from SS and NS environments. Progeny plants derived from SS exhibited significant improvements in key physiological traits, including increased relative water content (14%-16%), membrane stability index (6%-45%) and pollen viability (8%-13%) over NS-derived plants. Notably, SS-derived plants achieved yield advantages of up to 16% and 32% over NS-derived plants in the first and second seasons, respectively. Biochemical analyses further revealed enhanced antioxidant defence mechanisms in SS-derived plants, with increased activities of catalase (39%-50%) and peroxidase (33%), along with increased chlorophyll (44%-72%) and carotenoid (28%-32%) contents over NS-derived plants, indicating improved protection against oxidative stress. In addition, greater proline accumulation (15%-58%) and enhanced Photosystem II efficiency (7%-11%) were recorded in SS-derived plants over NS-derived plants, reflecting superior adaptive responses to drought stress. Genotype-specific differences were evident, with ICCV191218 and ICCV191229 consistently exhibiting superior performance and yield stability, and ICCV191218 was identified as the most stable across environments. These results demonstrate that exposure to high temperatures during seed development induces transgenerational tolerance to drought stress. The use of summer-developed seeds thus represents a low-cost, field-based strategy to enhance drought tolerance and yield stability in chickpea, offering a promising approach for improving crop adaptation in water-limited agroecologies.