[Effect of exogenous calcium on seed germination and seedling physiological characteristics of Lycium ruthenium].

OBJECTIVE: In order to get the method for improving the salt resistance of Lycium ruthenium seeds and seedlings under NaCl stress, the seed germination and physiological characteristics of L. ruthenium seedlings was studied. METHOD: Several physiological indexes of L. ruthenium seeds under NaCl stress, such as the germination rate (Gr), germination vigor (Gv), germination index (Gi), vigor index (Vi), and relative salt damage rate were measured. Other indexes of the seedlings like relative water contents (RWC) , chlorophyll contents, soluble protein contents, electrolyte leakage, the contents of malondialdehyde (MDA), and peroxidase (POD) were also measured. RESULT: NaCl at lower concentration could promote the seed germination but inhibit the seed germination at higher concentration. After the treatment by CaCl2 at the different concentrations, all germination indexes were increased. With the increase of salt concentration, the relative water contents and the contents of chlorophyll were decreased, the content of MDA and electrolyte leakage were increased. The change trend of POD activity showed the first increase and then decrease with the increase of salt concentration, which was similar to that of the soluble protein. After the treatment by CaCl2, relative water contents, chlorophyll and POD activities were decreased more slowly, and also electrolyte leakage and MDA contents increased slowly. CONCLUSION: The CaCl2 could significantly alleviate the damages to the seeds and seedlings of L. ruthenium under NaCl stress, and promote the salt resistance to the seeds and seedlings of L. ruthenium.

[Effects of different salt-alkaline stress on seed germination and seedling physiological characteristics of Codonopsis pilosula].

OBJECTIVE: To improve salt resistance of Codonopsis pilosula seeds and seedlings under different salt-alkaline stress, the seed germination and physiological characteristics of seedlings were studied. METHODS: Several physiological indexes of Codonopsis pilosula under different salt-alkaline stress were measured, such as the germination vigor, germination rate, relative germination rate and recovery germination rate,as well as others indexes like the contents of chlorophyll, soluble protein, water and MDA and the activities of POD and SOD. RESULTS: The inhibitory effects of three salts on seed germination were Na2 CO3 > NaCl + Na2 CO3 > NaCl with an increased salt concentration. The contents of chlorophyll, soluble protein and water were found significant different (P < 0.05) from the negative control group, along with the decreased of these indexes. However, positive correlation existed between MDA content and salt treatment concentration. In addition, the change trend of SOD and POD activity were similar. They were increased firstly, and then decreased as the stress intensity extended. CONCLUSION: The seeds and seedlings under different salt-alkaline stress were inhibited, with different inhibitory extent as Na2CO3 > NaCl + Na2 CO3 > NaCl.

[Effects of different salt-alkaline stress on seed germination and physiological characteristics of Hedysarum polybotrys].

OBJECTIVE: In order to get the method for improving the salt resistance of Hedysarum polybotrys seeds and seedlings under different salt-alkaline stress, the seed germination and physiological characteristics of H. polybotrys seedlings were studied. METHOD: Several physiological indexes of H. polybotrys seeds under different salt-alkaline stress, such as the germination vigor, germination rate, relative germination rate, relative salt damage rate were measured. And others indexes of the seedlings like chlorophyll contents, soluble protein contents, the permeability of plasmalemma, the activities of POD and SOD were also measured. RESULT: Different salt-alkaline stress decreased the germination rate, vigor of germinate, germination index, while relative salt damage rate increased. With the increased salt-alkaline concentration, the adverse effects became more obvious. The strength of the salts: Na2CO3 > Na2SO4 > NaCl. With the increase of the salt-alkaline concentration, the chlorophyll contents and the soluble protein contents decreased, but the permeability of plasmalemma increased. The change trend of SOD and POD activity was similar, it is increased firstly, and then decreased as the stress intensity extended, the most significant increase of Na2SO4 and Na2CO3 in the concentration of salt-alkaline was 25 mmol x L(-1), but NaCl was 50 mmol x L(-1). CONCLUSION: The seeds and seedlings inhibition of the salts was Na2CO3 > Na2SO4 > NaCl.