外源抗坏血酸对镉毒害小麦幼苗的缓解作用  

Alleviative Effect of Exogenous Ascorbic Acid on Cadmium Toxicity in Wheat Seedlings

作　　者：常云霞[1,2] 徐克东[2] 刘彬[1] 罗陈萍 王红星[1] 李季平[1] 陈龙[1] 

机构地区：[1]周口师范学院生命科学与农学学院,河南周口466001 [2]周口师范学院植物遗传与分子育种重点实验室,河南周口466001

出　　处：《麦类作物学报》2017年第2期246-252,共7页Journal of Triticeae Crops

基　　金：河南省科技厅重点科技攻关项目(152102310383);河南省高等学校重点科研项目(16A180055);周口师范学院中青年骨干教师培养项目

摘　　要：为了解抗坏血酸(AsA)对Cd2+毒害小麦幼苗生长的缓解作用,以小麦品种周麦27为材料,采用室内水培法分析了在Cd2+胁迫下小麦幼苗经不同浓度AsA处理后的生长及生理变化。结果表明,外源AsA能显著提高Cd2+胁迫下小麦幼苗的株高、根长、地上部干重、根系干重、根系活力、光合色素含量、渗透调节物质含量、抗氧化酶活性及叶片净光合速率、气孔导度和蒸腾速率,显著降低丙二醛含量和相对电导率以及叶片胞间CO2浓度。说明Cd2+胁迫下外源AsA可以通过提高小麦幼苗渗透调节物质含量及抗氧化酶活性来清除活性氧自由基,减少其对光合色素蛋白大分子的攻击作用,降低膜脂过氧化伤害程度,维持光合作用和细胞膜的稳定性,从而缓解了Cd2+对幼苗生长的毒害作用,其中以35mg·L-1 AsA的缓解效果最好。To understand the regulation effects of applying ascorbic acid （AsA） on the resistance to Cd2＋ of wheat seedlings, wheat cultivar Zhoumai 27 was used as the experimental material in this stud-y. The effects of AsA on the growth of wheat seedlings under Cd2＋ stress were studied through hy-droponic method. The results showed that after application of AsA, the plant height, root length, dry weight of shoot and root,root activity,the contents of photosynthetic pigment and osmotic adjustment substances and the activities of antioxidant enzymes, and the net photosynthesis rate, stomatal con-ductance, and transpiration rate of wheat seedlings under Cd2＋ stress were significantly increased. While,the content of malonaldehyde, the relative conductivity and the intercellular C02 concentration were significantly decreased. It is suggested that the harmful effects of Cd2＋ stress on wheat seedlings were mitigated by applying AsA through increasing the contents of osmotic adjustment substances in wheat seedlings and increasing the activities of the antioxidant enzymes to reduce the damage from peroxidation of membrane lipid. The optimal AsA concentration was 35 mg · L-1.

关 键 词：小麦幼苗 抗坏血酸 镉毒害 生长 渗透调节物质 光合特性 抗氧化酶活性 

分 类 号：S512.1[农业科学—作物学] S311