The salt-sensitive buckwheat variety ( TQ-0808) was used as experimental material, which was treated with different concentrations of Mg2 ＋ under NaCl stress of 100 mmol/L to study the effect of exogenous Mg2＋ on physiological characters of salt tolerance in buckwheat. The results showed that the exogenous Mg2 ＋ treatment of 40 mmol/L could significantly decrease the plasmalemma permeability and malondialdehyde ( MDA ) content of buckwheat leaves,and obviously increase the superoxide dismutase ( SOD) activity and net photosynthetic rate of buckwheat leaves, which made the SOD activity of buckwheat leaves under NaCl stress close to the control level,and the net photosynthetic rate of buckwheat leaves reach the control level. It indicated that appropriate concentrations of exogenous Mg 2＋ treatment could obviously improve the physiological characters of salt tolerance in buckwheat and had better mitigation to salt stress,while too high concentrations of exogenous Mg 2＋ might aggravate stress.%以盐敏感荞麦品种TQ-0808为试验材料,在100 mmol/L NaCl胁追下进行不同浓度的外源Mg2+处理,探讨外源Mg2+对养麦耐盐生理特性的效应.结果表明,40 mmol/L外源Mg2+处理能显著降低NaCl胁迫下荞麦叶片质膜透性和丙二醛(MDA)含量,明显增加NaCl胁迫下荞麦叶片超氧化物歧化酶(SOD)活性和净光合速率,使NaCl胁迫下荞麦叶片SOD活性接近对照水平,荞麦叶片净光合速率达到对照水平.说明适当浓度的外源Mg2+处理可明显改善盐胁迫下荞麦幼苗的生理特性,对盐胁迫具有较好的缓解作用；而外源Mg2+浓度过高可能会加剧胁迫.
展开▼
