镍胁迫对紫花苜蓿种子萌发及生长生理的影响

Effects of Nickel Stress on Seed Germination and Growth Physiology of Medicago sativa L.

以紫花苜蓿为试材,采用水培试验方法,研究不同镍浓度胁迫(0、1、5、10、50、100、200 mg·L^(-1))对紫花苜蓿种子和幼苗的生长生理指标影响,以期了解紫花苜蓿在重金属胁迫下生长生理变化,为紫花苜蓿应用于土壤修复提供参考依据。结果表明:在胁迫高于5 mg·L^(-1)时,紫花苜蓿种子萌发开始受到抑制,种子活力指数明显下降;幼苗期(10 d)叶绿素、蛋白质含量下降,活性氧、膜脂过氧化产物(丙二醛)含量增加,超氧化物歧化酶、过氧化物酶活性、脯氨酸及可溶性糖含量上升,幼苗对镍的吸收呈倍数增长,幼苗正常生长代谢受到影响。试验表明苜蓿在低浓度镍胁迫时能通过一系列氧化应激响应维持正常生长代谢水平,表现出一定的抗镍性。

Taking alfalfa as test materials, the hydroponic experiment method was used, the effects of different nickel concentrations stress(0,1,5,10,50,100,200 mg·L^(-1)) on alfalfa seeds and seedlings growth physiological indicators were studied, in order to understand the alfalfa growth physiological changes under heavy metal stress, and provide a reference for alfalfa applied to soil restoration.The results showed that seed germination of alfalfa was inhibited and seed vigor index under stress decreased significantly higher than 5 mg·L^(-1).At the seedling stage(10 days),the contents of chlorophyll and protein decreased, the contents of reactive oxygen and membrane lipid peroxidation products(malondialdehyde) increased, the activities of superoxide dismutase and peroxidase, the contents of proline and soluble sugar increased, and the absorption of nickel to the seedlings increased multiple, which affected the normal growth and metabolism of the seedlings.Test showed that alfalfa could maintain the normal growth metabolic level through a series of oxidative stress responses under low concentration of nickel stress and showed certain nickel resistance.