渗滤液灌溉对香根草胁迫及抗氧化系统的影响

以香根草(Vetiveria zizanioids)和渗滤液循环出水为实验材料,比较了不同体积浓度渗滤液灌溉对香根草胁迫相关生理指标及抗氧化系统的影响.结果表明,与对照相比,小于35%浓度的渗滤液灌溉6个月降低了香根草叶片脯氨酸(Pro)含量和相对膜透性,提高了叶绿素、蛋白质、抗坏血酸(AsA)、还原型谷胱甘肽(GSH)含量和叶绿素a/b值,过氧化物酶(POD)和超氧化物岐化酶(SOD)被激活,丙二醛(MDA)含量被控制在较低的水平上,表明低浓度渗滤液灌溉有利于香根草生长.大于35%浓度的渗滤液灌溉,随浓度的增大,香根草叶绿素含量和a/b值明显降低,MDA、H₂O₂、Pro进一步积累,相对膜透性显著增加,AsA、GSH含量下降,SOD和POD活性受抑制,表明高浓度渗滤液灌溉会造成活性氧产生和抗氧化系统清除之间的失衡,导致膜脂过氧化作用加剧,会加重对香根草的胁迫.灌溉6个月较3个月相比,叶绿素含量下降,Pro、MDA积累,表明灌溉时间延长也会导致胁迫加重.

Influence of landfill leachate irrigation on stress and antioxidant system of Vetiveria zizanioides

Using Vetiveria zizanioides and recirculated leachate as testing material, the influence of irrigation of leachate of different volumn concentration on the Vetiveria zizanioides stress related physiological indexes and the anti-oxidant system was compared. Compared with the control group, irrigated with leachate of concentration less than 35% for six months, proline content and relative membrane permeability of Vetiveria zizanioides leaf decreased, the contents of chlorophyll, protein, ascorbic acid (AsA), glutathione (GSH) and the chlorophyll of a/b value increased; peroxidase (POD) and super oxide dismutase (SOD) activity were activated; malondialdehyde (MDA) content was controlled at lower level; these indicated that irrigation with leachate of low concentration was beneficial to Vetiveria zizanioides growth. Irrigated with leachate volume concentration more than 35%, following increase of the concentration, chlorophyll content of Vetiveria zizanioides and a/b value decreased obviously, MDA, H2O2 and proline accumulated further; relative membrane permeability increased markedly; the contents of AsA and GSH decreased , the activity of SOD and POD was inhibited. These indicated that irrigation with high concentration leachate could break the balance between the production of active oxygen and the removal of antioxidation system, causing the exacerbation of peroxidation of membrane grease; and might aggravate the stress on Vetiveria zizanioides. Campaing the irrigation of 6 to 3 months, chlorophyll content declined, proline and MDA accumulated, indicating that exacerbation of coercion might be caused by the elongation of irrigation time.