沙埋对小麦(Triticum aestivum)生长的影响及其生理响应

为了解沙埋对小麦(Triticum aestivum)生长的影响及其生理响应,2010年在科尔沁沙地研究了不同沙埋深度下小麦的存活率、株高、地上地下生物量、籽实产量、丙二醛(MDA)含量、膜透性、保护酶(超氧化物歧化酶,SOD;过氧化物酶,POD;过氧化氢酶,CAT)活性和渗透调节物质含量变化。结果表明:随着沙埋深度的增加,小麦存活率、株高、地上地下生物量和籽实产量均显著下降,完全沙埋下第6天以后植株全部死亡。沙埋第6天,随着沙埋深度的增加,MDA含量、CAT活性、可溶性糖含量下降,POD活性变化不明显,但膜透性、SOD活性和脯氨酸含量显著增加。沙埋第12天,随着沙埋厚度增加,MDA含量和膜透性,SOD、POD和CAT活性,脯氨酸和可溶性糖含量均显著增加。沙埋导致小麦死亡率增加、株高及生物产量下降的主要原因不是水分胁迫,沙埋导致的光合面积降低、黑暗和无氧呼吸可能是其死亡和生长受到抑制的主要外部因素,而膜脂过氧化导致的膜透性增加可能是其死亡或生长受到抑制的主要生理机制。保护酶活性增强和渗透调节物质含量增加,对于减轻其细胞膜受损和防止细胞质渗漏起到了重要作用。

Effects of Sand Burial on Growth of Wheat and Its Physiological Responses

Changes on survival rate, plant height, above and below ground biomass, seed yield, malondialdehyde, membrane permeability, protect enzyme activity and osmotic regulation substances of wheat in different sand burial depths was studies during 2010-2011 in the Horqin Sand Land of Inner Mongolia to understand effects of sand burial on wheat growth and its physiological response. The results showed that the survival rate, plant height, above and below ground biomass, seed yield decreased significantly with creasing sand burial, all seedlings died at sixth day in the complete sand burial. At the sixth day of sand burial, malondialdehyde content, catalase activity and soluble sugar content decreased significantly with increase of sand burial depth, while membrane permeability, superoxide dismutase activity and proline content increased significantly and change of peroxidase activity was not significant. At the s twelfth day of sand burial, malondialdehyde and membrane permeability, activities of superoxide dismutase, peroxidase and catalase, as well as proline and soluble sugar contents increased significantly with increase of sand burial depth. Main causes on increased mortality, growth inhibition and decreased biomass is not water stress in sand burial stress, which should be attribution to a decrease of photosynthetic area, dark and anaerobic respiration, as well as lipid peroxidation and cell membrane damage. But increase of protective enzyme activities and osmotic regulation substances played an important role to reduce cell membrane damage and prevent the leakage of cytoplasm.