外源多元醇对盐胁迫下荞麦种子萌发及幼苗生理特性的影响

摘要

Salt-sensitive buckwheat variety TQ-0808 was treated as experimental material .Under NaCl stress of 100 mmol/L and adding different concentrations of mannitol and sorbitol treatment to study the effects of exogenous polyols on seeds germination and seedlings physiological traits of buckwheat .The results showed that the appropriate concentrations of exogenous mannitol and sorbitol treatment could significantly increase the germination rate ( Gr) , germination index ( Gi) and vigor index ( Vi) of buckwheat seeds ,and significantly promote the seedlings growth and increase the nitrate reductase(NR)activity,superoxide dismutase(SOD)activity and ascorbate peroxidase(APX)ac-tivity of buckwheat seedlings under salt stress ,which could also significantly decrease the plasmalemma permeability of buckwheat seedlings under salt stress , and significantly increase the chlorophyll content and net photosynthetic rate of buckwheat seedlings .It indicated that the appropriate concentrations of mannitol or sorbitol treatment could significantly improve seeds germination and seedlings growth of buckwheat ,and significantly improve the physiologi-cal traits of buckwheat seedlings .The optimal concentrations of exogenous mannitol and sorbitol treatment were 0.8, 0 .6 mmol/L respectively ,and the effects of exogenous mannitol treatment were better than those of sorbitol did .%以盐敏感荞麦品种TQ-0808为试验材料，在100 mmol/L NaCl胁迫下添加不同浓度甘露醇和山梨醇处理，研究外源多元醇对荞麦种子萌发及幼苗生理特性的影响。结果表明，适当浓度的外源甘露醇和山梨醇处理能显著增加盐胁迫下荞麦种子的发芽率（Gr）、发芽指数（Gi）和活力指数（Vi），明显促进盐胁迫下荞麦幼苗生长及显著增加荞麦幼苗硝酸还原酶（ NR）、超氧化物歧化酶（ SOD）及抗坏血酸过氧化物酶（ APX）活性，显著降低盐胁迫下荞麦幼苗的质膜透性，显著增加荞麦幼苗叶绿素含量和净光合速率。说明适当浓度甘露醇和山梨醇处理可以显著促进盐胁迫下荞麦种子萌发及幼苗生长，显著改善盐胁迫下荞麦幼苗的生理特性。外源甘露醇和山梨醇处理的最适浓度分别为0.8，0．6 mmol/L，且外源甘露醇处理的效果好于山梨醇处理。