[Effects of exogenous Ca²⁺ on growth and development, physiology and yield of peanut under salt stress]

Huayu 22, one of the peanut (Arachis hypogaea) cultivars, was used as material in this study. Peanuts, which grew under normal conditions and 100 mmol·L^-1 NaCl stress, were treated with 0, 6, 12 mmol·L^-1 Ca(NO₃)₂ respectively to elucidate the effects of exogenous calcium on peanut salt tolerance. The effects of different Ca²⁺ concentrations on the physiological indices and yield of peanut during the whole growth period under salt stress were investigated in potted plants, with the aim to provide theoretical basis for the growth and production of peanut in saline soil. The results showed that, under salt stress, the activities of superoxide dismutase (SOD), catalase (CAT), and chlorophyll content increased whereas the MDA content and electrolytes decreased when treated with different concentrations of exogenous calcium. Calcium also improved root activity, biomass, improved agronomic traits, and finally increased peanut yield. Among all the exogenous calcium treatments, the effect of 12 mmol·L^-1 Ca²⁺ treatment was the most significant. These results indicated that exogenous calcium could alleviate the salt stress on peanut plants and enhance the yield of pods by enhancing the scavenging ability of active oxygen, maintaining the stability and integrity of cell membrane.