根际pH对高产杂交稻幼苗根系抗氧化系统的影响

摘要

采用砂培法培养,模拟不同土壤pH(4.0、5.0、6.0、7.0和8.0)的胁迫环境,研究根际pH对“两优培九”幼苗根系的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性,丙二醛(MDA)、抗坏血酸(AsA)、谷胱甘肽(GSH)的含量,超氧阴离子产生速率的影响.实验结果表明,不同pH培养条件下,水稻幼苗根部3种抗氧化酶活性、AsA与GSH的含量、MDA含量和超氧阴离子的产生速率存在较为明显的差异.当pH为6.0时,超氧阴离子的产生速率最弱,MDA含量最低,而SOD与CAT活性最大,AsA与GSH含量均最高；pH低于或高于6.0时,上述各生理指标均与对照组(pH6.0)之间存在显著差异.可见,从根系抗氧化系统特性的角度来看,“两优培九”幼苗生长的最适土壤pH应为6.0.%The effects of different rhizosphere pH (4.0、5.0、6.0、7.0 and 8.0) on the activities of superoxide dismutase ( SOD), peroxidase (POD) and catalase (C AT) , the contents of malondialdehyde ( M DA), ascorbic acid (As A ) and Glutathione (GSH) ,and the production rate of superoxide anion were studied in roots of the hybrid rice " Liangyoupei-jiu" seedlings with sandy culture. The results showed that, compared with the other groups, in the roots of the control (pH6.0), the production rate of 02-' and contents of MDA were the lowest, whereas the activities of SOD and CAT were the strongest, and the contents of As A and GSH were the highest. When the pH <6.0 or pH >6.0, there was significant difference between the control and the other groups in the above physiological indexes. Therefore, the rhizosphere pH 6. 0 is the most optimal for seedling growth of the hybrid rice "Liangyoupeijiu".