溴敌

发布时间：2018-05-09 04:28

本文选题：溴敌隆 + 氰戊菊酯　；参考：《浙江大学》2015年硕士论文

【摘要】：农药的大量使用造成了严重的环境污染,对生态系统构成了严重威胁。本研究以土壤生态系统中广泛采用的无脊椎动物蚯蚓为模式生物,研究了目前广泛使用的溴敌隆、氰戊菊酯和哌虫啶三种农药对蚯蚓的急性毒性、体重变化、氧化损伤和生物富集作用。溴敌隆是一种广泛使用的第二代抗凝血灭鼠剂,目前尚无溴敌隆对蚯蚓毒性的相关报道。本研究发现,土壤中溴敌隆的浓度达到1mg/kg,即会对蚯蚓产生毒性作用,这一浓度在野外农田中可能达到,因此可认为暴露溴敌隆会对蚯蚓产生潜在风险。同时,暴露亚致死浓度的溴敌隆会抑制蚯蚓的生长。本研究还发现,溴敌隆暴露下,与对照组相比,蚯蚓体内抗氧化防御系统酶SOD和CAT活性没有显著性变化,而MDA含量显著增加。结果表明,MDA是较敏感的生物标志物。本研究还发现,随着暴露时间的增加,溴敌隆能富集到蚯蚓体内,而且富集浓度与土壤中溴敌隆浓度有关。溴敌隆在蚯蚓体内的生物富集因子(BSAFs)随着土壤中溴敌隆浓度的增加而减小。本研究结果表明,溴敌隆使用后蚯蚓不仅是潜在的中毒目标,而且是食虫动物和食腐动物二次暴露的来源。氰戊菊酯是一种典型的手性拟除虫菊酯杀虫剂,其S型对映体即顺式氰戊菊酯为其有效活性成分。本研究比较了氰戊菊酯外消旋体与顺式氰戊菊酯对蚯蚓的毒性和生物富集的对映体选择性。研究结果表明,顺式氰戊菊酯对蚯蚓的毒性比氰戊菊酯毒性更大。研究还发现,随着暴露时间的延长,氰戊菊酯和顺式氰戊菊酯的暴露会抑制蚯蚓的生长,而且顺式氰戊菊酯对蚯蚓生长的抑制作用更强。本实验中顺式氰戊菊酯对蚯蚓生长的抑制作用更强,可能是因为顺式氰戊菊酯对蚯蚓毒性更大,蚯蚓体内糖原和脂肪消耗以及蛋白质含量降低更多,从而导致顺式氰戊菊酯暴露下蚯蚓体重抑制作用更加明显。研究结果表明,暴露氰戊菊酯和顺式氰戊菊酯后,蚯蚓体内抗氧化酶活性较为一致,即蚯蚓体内CAT活性先被抑制,后随着暴露时间的增加被显著诱导；蚯蚓体内SOD整体上均被显著诱导；蚯蚓体内MDA含量变化有较大差异。研究结果表明,对于氰戊菊酯,SOD是较敏感的生物标志物,而对于顺式氰戊菊酯,MDA是较敏感的生物标志物。研究发现,随着暴露时间的增加,氰戊菊酯和顺式氰戊菊酯能富集到蚯蚓体内,而且毒性小的氰戊菊酯在暴露末期生物富集因子(BSAFs)更大。研究表明,在评价手性农药对生物的毒性和生物富集时应考虑对映体选择性。哌虫啶是我国自主研制的新型创制农药,目前尚无其对蚯蚓的毒性评价数据。研究发现,哌虫啶属于低毒农药,而且比其他烟碱类杀虫剂的毒性低。土壤中哌虫啶浓度达到的50mg/kg就会对蚯蚓产生毒性作用。研究还发现,长时间暴露哌虫啶会抑制蚯蚓的生长。研究结果表明,哌虫啶暴露下,蚯蚓体内CAT和SOD均被显著诱导,而且CAT在最短暴露时间最低浓度0.1mg/kg即有显著作用,表明CAT是对哌虫啶更为敏感的生物标志物。只有在高浓度和长时间暴露下,MDA含量有显著性变化,表明MDA对哌虫啶的暴露不敏感。本研究丰富了蚯蚓作为模式生物的毒性数据,同时也为三种农药在土壤中的生态风险评价提供了更加有力的科学依据。
[Abstract]:The extensive use of pesticides has caused serious environmental pollution and poses a serious threat to the ecosystem. In this study, the extensive use of invertebrate earthworms in the soil ecosystem was used as a model organism. The acute toxicity, body weight change and oxidation loss of three kinds of agricultural drugs which were widely used at present were studied. Brulide and bioaccumulation. Brobrom is a widely used second generation anticoagulant rodenticide. At present, there is no related report on the toxicity of brobrom on earthworm. This study found that the concentration of bromate in the soil is 1mg/kg, which is toxic to earthworms. This concentration may be reached in the field outside the field. Therefore, the brominated enemy can be exposed to the brominated enemy. In this study, there was no significant change in the activity of enzyme SOD and CAT in the antioxidant defense system in the earthworms compared with the control group, and the MDA content increased significantly. The results showed that MDA was a more sensitive biomarker. The study also found that with the increase of exposure time, the concentration of the eisenon can be enriched in the earthworms, and the concentration of the enrichment factor is related to the concentration of the medium in the soil. The bioaccumulation factor (BSAFs) in the earthworm is decreased with the increase of the concentration of the medium in the earthworm. The toxic target, and the source of two exposure of insectivorous animals and rotten animals. Fenvalerate is a typical chiral pyrethroid insecticide, its S enantiomer is cis fenvalerate as its active component. This study compared the toxicity and bioaccumulation of fenvalerate racemate and CIS fenvalerate to earthworms. The results showed that the toxicity of CIS fenvalerate to earthworms was more toxic than that of fenvalerate. The study also found that the exposure of fenvalerate and CIS fenvalerate could inhibit the growth of earthworms with the exposure time, and the inhibitory effect of CIS fenvalerate on earthworm growth was stronger. The inhibitory effect of ester on earthworm growth is stronger, probably because CIS fenvalerate is more toxic to earthworms, the consumption of glycogen and fat and the decrease of protein content in earthworms are more obvious, which leads to more obvious inhibition of earthworm body weight under the exposure of fenvalerate. The activity of antioxidant enzymes in earthworms is more consistent, that is, the CAT activity in earthworms is inhibited first and then is significantly induced with the increase of exposure time; the SOD in the earthworms are all significantly induced in the earthworms, and the changes of MDA content in the earthworms are different. The results show that the SOD is a more sensitive biomarker for fenvalerate, and for the fenvalerate. CIS fenvalerate, MDA is a more sensitive biomarker. The study found that Fenvalerate and CIS fenvalerate can be enriched in earthworms with the increase of exposure time, and the small toxic fenvalerate (BSAFs) is greater at the end of exposure. The study shows that the toxicity and bioaccumulation of chiral pesticides to organisms are evaluated. The enantioselectivity should be considered. Piperidin is a new type of pesticide created by our country. At present, there is no toxic evaluation data on earthworms. It is found that piperidin belongs to low toxic pesticide and is less toxic than other nicotinic insecticides. The 50mg/kg of piperidine concentration in soil will be toxic to earthworms. The long-term exposure of piperidin could inhibit the growth of earthworms. The results showed that CAT and SOD were significantly induced by piperidine exposure, and the minimum concentration of 0.1mg/kg in the shortest exposure time of CAT was significant, indicating that CAT was a more sensitive biomarker for piperidin. Only at high concentration and long exposure, MDA There is a significant change in content, which indicates that MDA is not sensitive to the exposure of piperidin. This study enriches the toxic data of earthworms as model organisms, and also provides a more powerful scientific basis for the ecological risk assessment of three pesticides in soil.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X592

【参考文献】