Effect of Gibberellin, Calcium,and Betaine on Seed Germination and Resistance of Jatropha curcas L.Seedlings to Low Temperature and Drought Stress

Jatropha curcas L.is an energy plant of the Euphorbiaceae family.Using seeds and seedlings of J.curcas as materials,the effect of different concentrations of gibberellin or calcium treatment,or combination treatment of different concentrations of gibberellin,calcium, and betaine on seed germination and resistance of seedlings to low temperature or drought stress were investigated.The application of 10 mg/L gibberellin or 10 mmol/L calcium not only improved germination percentage of J.curcas seeds under normal conditions (26℃),low temperature (18℃),and drought stress (5% PEG6000),but also alleviated electrolyte leakage and accumulation of MDA in J.curcas seedlings under low temperature (2℃) and drought stress (25% PEG6000) compared with the control. In addition,combination treatments with 10 mg/L gibberellin,5 mmol/L calcium,and 15 mmol/L betaine also enhanced germination percentage of J.curcas seeds under normal conditions (26℃),low temperature (18℃),and drought stress (5% PEG6000),and alleviated electrolyte leakage and accumulation of MDA in J.curcas seedlings under low temperature (2℃) and drought stress (25% PEG6000),illustrating that treatment with 10 mg/L gibberellin or 10 mmol/L calcium,or combination treatments of 10 mg/L gibberellin,5 mmol/L calcium,and 15 mmol/L betaine increased germination percentage of J.curcas seeds under low temperature and drought stress,and resistance of seedlings to low temperature or drought stress.