Effect of spermidine on reproductive, seed quality and bio-physiological characteristics of chickpea (Cicer arietinum L.) genotypes under salt stress

The experiment aimed to investigate the impact of foliar application of spermidine on the physiological and reproductive aspects of chickpea genotypes subjected to salt stress, with a focus on its consequences for seed quality. The study involved treating chickpea genotypes (CSG 8962, HC 3, HC 5, RSG 931) with 4 and 8 dSm(-1) Cl(- )dominate salinity during the seedling stage, and application of 0.5 and 1.0 mM spermidine at the flowering stage. Result revealed that salinity significantly reduced chlorophyll and membrane stability index by approximately 46.97% and 23.19%, respectively. Concurrently, pollen germination and viability decreased about 14.14% and 22.24%, leading to a substantial decline in seed protein content (37.70%) at 8 dSm(-1) salinity. While there was an increase in antioxidant activity (45.83%), phenol content decreased in response to salinity stress. Foliar application of spermidine (0.5 and 1.0 mM) proved to be a promising intervention, enhancing chlorophyll stability and phenol content by approximately 24.35% and 36.05%, respectively, at 8 dSm(-1) salinity. This improvement is associated with a notable 20.01% increase in pollen viability, resulting in a subsequent rise in protein content by about 20.73% at 1.0 mM spermidine. Additionally, the application of spermidine mitigated Na+ ion accumulation in chickpea seeds. The findings underscore the varying performance of chickpea genotypes under salinity stress, with CSG 8962 and RSG 931 exhibiting poorer outcomes compared to other genotypes. Notably, the positive impact of spermidine was more pronounced, especially with the use of 1.0 mM spermidine, which demonstrated a more significant positive effect in salt-sensitive chickpea genotypes. These results emphasize the potential of spermidine as a strategic tool in alleviating the adverse effects of salinity on chickpea crops, offering valuable insights for the development of sustainable practices to enhance chickpea resilience and seed quality under challenging environmental conditions.