【作者】 汤奕昕；

【导师】 寿森炎；

【作者基本信息】 浙江大学 ， 蔬菜学， 2008， 硕士

【摘要】 茭白（Zizania caduciflora Turcz Hand-Mazz）,为禾本科多年生水生宿根性草本植物,是我国重要的水生蔬菜之一,而有机物-重金属复合污染成为当今世界面临的一个严峻问题。本试验以水生蔬菜茭白为对象,研究其对阴离子表面活性剂（LAs）与重金属镉（cd）复合污染环境的生物修复能力,以及自身对环境胁迫产生的一系列抗性反应。1.茭白对阴离子表面活性剂（LAS）与重金属镉（cd）复合污染的抗性生理研究:采用土培的试验方法,研究了在不同程度的LAS与cd复合污染条件下,双季茭“浙大3号”的生长情况、叶片中抗氧化酶系统的活性和可溶性蛋白含量。结果显示,同时期单一LAS和同以cd浓度的LAS-Cd复合污染条件下,随着LAS浓度的增大,APX、SOD活性大致上表现出先升高后下降的趋势,POD活性不断增大,MDA含量逐渐增多。在单一cd污染条件下,随着cd浓度的增大,APX活性基本上呈现出先上升后下降的变化趋势,而POD、SOD活性上升,MDA含量升高。通过这些生长及生理生化指标的测定,可以得知茭白对Cd的忍耐能力较强,茭白自身抵御LAS-Cd胁迫的极限可能存在于LAS浓度为60mg·L^-1-120mg·L^-1处,低于该浓度的LAS能部分缓解重金属cd的毒害作用,而高浓度下两者间可能存在协同效应。2.茭白对土壤-水环境中LAS的吸收和降解研究:试验结果显示,LAS在土壤中、叶片中的残留量均随着LAS处理浓度的增大而增加,但其去除率则呈现出先上升后下降的趋势。在试验期间随时间推移,茭白叶片中LAS相对含量呈现出先下降后增加的变化趋势;同时期茭白肉质茎中的LAS相对含量显著低于叶片中的含量,说明LAS在膨大肉质茎中的积累量可能存在上限,茭白叶片可能是植株吸收、同化、降解LAS的主要场所。试验证明低浓度的LAS能够促进茭白吸收、降解土壤-水环境中的LAS,有效降低其在土壤和植株中的残留量;而高浓度的LAS(480mg·L^-1)则抑制茭白植株的吸附、吸收和降解功能。更多还原

【Abstract】 Water bamboo （Zizania caduciflora Turcz Hand-Mazz） is one of the unique aquatic vegetables with great importance in China. People have concerned more about our environmental problems and shifted the priority to those compound pollutions, especially those by organic and heavy mental. In this paper, we studied the combined impacts of linear alkylbenzene sulfonate （LAS） and heavy mental （Cd） on water bamboo - soil system, the resistance response to the compound pollution and the abilities of water bamboo of absorption and degradation for LAS pollution. The results were reported as follows:1. Impacts of the compound pollution by linear alkylbenzene sulfonate （LAS） and Cd on water bamboo - soil system: Impacts of different concentrations of LAS (0, 60, 120, 240mg·L^-1) and Cd (0,50,100mg·L^-1) on growth, soluble protein content and antioxidant system in the leave of Zizania latifolia Turcz at different periods were studied. The results showed that with the continuously increasing concentrations of LAS, the activities of APX and SOD increased observably at the early period and declined later with the lower concentration of LAS, while the activity of POD kept increasing. The contents of MDA always increased with the increasing concentration of LAS with the days going on. Under single Cd polluted conditions, the activities of POD and SOD in leaves were enhanced and the contents of MDA were added. Under the compound pollutions with the same level of Cd concentration, the activities and the MDA contents went similarly with that under single LAS treatment. We can find that the detoxification effects were relatively remarkable under lower LAS concentrations but enhanced the damage under higher concentrations..2. The absorption and degradation of LAS in the leaves and swelling stems of water bamboo, and the relative residue in the soil. In this experiment, the contents of LAS in the plant leaves descended firstly and then increased with the different concentrations at different periods. The contents of LAS in the swelling stems were at a lower standard. The results showed that Zizania latifolia Turcz had the stronger power of absorbing and degrading LAS compared with the single soil environment. The plant might absorb, assimilate and degrade the LAS through its own bio-repairing function. Within certain extent of pollution, the water bamboo can not only reduce the LAS contents in the soil, but also maintain a relative low level of LAS contents in its bodies. However, the high concentrations of LAS reaching 480mg·L^-1 may lead the accumulation of LAS in the soil. The results showed that there is a limit to the self-repairing ability in resisting LAS pollution near the LAS level of 240mg·L^-1.更多还原