Effect of low temperature stratification treatment on seed germination of Lycium ruthenicum under sodium salt stress

In this study, the effect of low temperature stratification treatment on seed germination characteristics of Lycium ruthenicum under sodium salt stress was investigated, which provided technical support for ecological restoration in saline-alkali land.

Different concentrations of NaCl solution (0.2%-1.4%) and complex salt solution (0.4%-2.0%) were used to simulate the salt stress environment, and the germination parameters and recovery ability of seeds were systematically analyzed.

Under NaCl stress, under 0.4% NaCl treatment, the seedling emergence rate of low temperature stratification reached the peak (2.67% higher than that of control group), and the seedling emergence potential was 87.33%. The seedling emergence rate was the highest (68.00%) when 0.8% NaCl was treated at room temperature. Under combined salt stress, the seedling emergence potential of low temperature stratification reached 87.33% when 0.8% concentration was treated, and the seedling emergence index was significantly increased by 10.01% compared with the control group (P<0.05). The rate of room temperature drying was increased by 42.00% compared with control. After salt stress relief, the recovery germination rate of seeds increased with the increase of salt concentration, and reached the maximum value (38.10% and 39.44%) under 1.4% NaCl and 2.0% combined salt treatment, respectively, indicating that the seeds had the ability to recover from strong stress. The critical points of germination inhibition were 0.6% NaCl concentration and 0.8% compound salt concentration, and the germination index decreased significantly after the concentration exceeded (P<0.05).

By breaking seed dormancy and activating endogenous activity, low temperature stratification significantly enhanced the adaptability of Lycium ruthenicum to sodium stress. 0.4% NaCl and 0.8% compound salt were the optimal germination promoting concentrations under the two treatments, respectively. The research results provided key parameters for salt concentration regulation and pretreatment technology optimization of artificial cultivation of Lycium ruthenicum seedlings in saline-alkali land, and had important guiding significance for desertification control and ecological restoration practice.