甲拌磷对土壤微生物活性影响及其在干旱区土壤中降解-effect of phorate on soil microbial activity and its degradation in arid soil.docxVIP

to detect phorate.6﹚The degradation of phorate in soil followed the first-order function. The half-life of phorate in soil under laboratory condition was measured to be 8.6d, 8.2d and 7.6d, at levels of2.0mg/kg, 8mg/kg and 20mg/kg, respectively, the half-life of phorate in soil reduced with the concentration phorate. The residues were found to be 0.153 mg/kg, 0.471 mg/kg and 0.839 mg/kg, 30 days after application of phorate at dosage of 2.0mg/kg, 8mg/kg and 20mg/kg, respectively, the degradation rate was over 90%.7﹚Under condition of 30℃ and PH 7, both XT1 and XT2 could degrade 500mg/Lphorate by more than 83% within 5days.8﹚Two phorate-degrading stains were isolated by enrichment culture from cotton land. Based on its morphological, physiological and biochemical properties , as well as 16S rDNAsequence analysis resules , the strain XT2 was tentatively indenifited as Providencia sp.【Conclusion】The microbial community structure was changed and the microbial activities were reduced when phorate was added to soil. The degradation rate of phorate was more fastin soil in arid area and the half-life was lower than 10days. Two phorate-degrading stains XT1 and XT2 which could degrade 500mg/L phorate by more than 83% within 5days, were isolated by enrichment culture.Key word: phorate; rhizosphere; soil microorganism; soil enzyme；SMB-C,N; residue; biodegradationIV石河子大学学位论文独创性声明及使用授权声明学位论文独创性声明本人所呈交的学位论文是在我导师的指导下进行的研究工作及取得的研究成果。据我所知，除 文中已经注明引用的内容外 ，本论文不包含其他个人已经发表或撰写过的研究成果。对本文的研究 做出重要贡献的个人和集体，均已在文中作了明确的说明并表示谢意。研究生签名：时间：年月日使用授权声明本人完全了解石河子大学有关保留、使用学位论文的规定，学校有权保留学位论文并向国家主 管部门或指定机构送交论文的电子版和纸质版。有权将学位论文在学校图书馆保存并允许被查阅。 有权自行或许可他人将学位论文编入有关数据库提供检索服务。有权将学位论文的标题和摘要汇编 出版。必威体育官网网址的学位论文在解密后适用本规定。研究生签名：时间：年月日导师签名：时间：年月日第一章 绪论1.1 甲拌磷在新疆农业生产中的应用概况甲拌磷(Phorate) 化学名称为 O,O-二乙基-S-(乙硫基甲基)二硫代磷酸酯，其分子式 为 C7H17O2PS3，分子量为 260.38，是一种高效、广谱、高毒的内吸性有机磷杀虫、杀螨 剂。甲拌磷具有触杀、胃毒作用，由于其挥发性相对较高，所以也具有熏蒸作用。甲拌 磷主要用于小麦、玉米、棉花、甘蔗、大豆等作物拌种或土壤施药，用来防治地下害虫 和农作物苗期害虫。其结构式见图 1-1图 1-1 甲拌磷的化学结构式Fig 1.1Chemical structure of phorate甲拌磷是