Effect of basic salt and mixed salt-alkali stress tolerance on seed germination and seedling physiological characteristics of Astraglus membranaceus var. mongholicus / 中草药

ABSTRACT

Objective: To compare the effects of Na2CO3 and NaCl + Na2CO3 at different concentration on the seed germination and seedling physiological characteristics of Astraglus membranaceus var. mongholicus, analyze the stress degrees of the both two on A. membranaceus var. mongholicus, and search for the effective ways for improving the resistance of seeds and seedlings under salt stress. Methods: Several physiological indexes of A. membranaceus var. mongholicus seeds under different salt treatments, such as the germination vigor (Gv), germination rate (Gr), relative germination rate, and relative salt damage rate were measured. And other indexes of the seedlings like chlorophyll contents, soluble protein contents, the contents of malondialdehyde (MDA), the activities of superoxide dismutase (SOD), and peroxidase (POD) were also measured. Results: Na2CO3 and NaCl + Na2CO3 at lower concentration could promote the seed germination but inhibit the seed germination at higher concentration. The inhibition was increased with the concentration increasing. The germination indexes of each treatment had the significant differences compared with the control (P < 0.05). With the salt concentration increasing, the contents of chlorophyll and the soluble protein decreased, which was negatively correlated with the concentration. The content of MDA was increased and positively correlated with the concentration. The change trend of SOD activity showed the first increase and then decreased with the salt concentration increasing, which was similar to that of POD. The activities of both SOD and POD reached the peak at 50 mmol/L. Conclusion: The stress of NaCl + Na2CO3 is higher than that of Na2CO3 on the seeds and seedlings of A. membranaceus var. mongholicus.