Mitigating Salinity Stress in Groundnut (Arachis hypogaea L.) Through Salicylic Acid Application

Abstract

Soil salinity is a major abiotic stress factor that adversely affects the growth, yield, and quality of many crops, including Arachis hypogaea (groundnut). This study investigated the potential of salicylic acid (SA) in mitigating the negative effects of salinity stress in groundnut. A germination experiment was conducted on two groundnut varieties, SAMNUT-11 and SAMNUT-14, which were exposed to varying concentrations of sodium chloride (NaCl) solutions (0, 50, 100, 150, and 200 mM), with or without SA treatment. The experiment followed a completely randomized design with ten treatment combinations and three replications. The effects of SA were evaluated on morphological parameters such as germination percentage, fresh weight, and plumule length, alongside key biochemical indicators of oxidative stress, including reactive oxygen species (ROS), malondialdehyde (MDA), and reduced glutathione (GSH). Results showed that SA significantly enhanced seed germination and seedling growth under saline conditions, particularly at moderate salt concentrations (≤100 mM). In addition, SA application effectively reduced ROS and MDA levels while increasing GSH content, indicating its protective role against oxidative damage. Among the two varieties tested, SAMNUT-14 exhibited greater salt tolerance, demonstrated by superior morphological performance and more favourable biochemical responses compared to SAMNUT-11. These findings suggest that exogenous SA application can improve salt tolerance in groundnut by modulating oxidative stress responses, offering a promising approach for enhancing crop productivity in saline soils. Further research is warranted to elucidate the underlying physiological and molecular mechanisms of SA-mediated stress mitigation and to optimize its field application.