朱砂叶螨抗甲氰菊酯品系选育及遗传分析

 从保留的室内相对敏感品系分出一个亚品系开始培育朱砂叶螨的甲氰菊酯抗药性品系。连续用药40代，抗性增长68.5倍。以此抗性品系（R）和相对敏感品系（S）杂交、回交，研究朱砂叶螨对甲氰菊酯的抗性遗传形式。正交（SR）和反交（RS）F1代的LC-P线介于S与R之间且偏向S方，显性度DSR和DRS分别为-0.83和-0.29，表明抗性由不完全隐性基因控制；两D值（DRS和DSR）95%置信限没有重叠，表明两个 D值（DSR和DRS）存在显著差异，也表明朱砂叶螨对甲氰菊酯的抗性遗传可能存在母体影响或核外效应；对F1杂合子与亲本的回交（SR♀×S♂和RS♀×R♂）F2代测定表明抗性由单基因控制。     

甲氰菊酯在土壤中的降解及对蚯蚓的毒性效应研究

拟除虫菊酯作为全球第三大杀虫剂品种，在农业生产中广泛使用，同时也带来了一系列不利的环境影响。然而，目前有关拟除虫菊酯在土壤环境中的残留行为和风险评估报道较少。以典型拟除虫菊酯类杀虫剂甲氰菊酯(FEN)为研究对象，重点探究其在不同性质土壤中的降解行为以及对典型土壤生物蚯蚓的毒性效应。结果表明，甲氰菊酯在碱性土壤中的降解速度快于酸性土壤，同时在非灭菌土壤中的降解速度为灭菌土壤的4倍。因此，土壤酸碱度和微生物是影响FEN在土壤中降解快慢的主要因素。此外，在降解过程中检测到甲氰菊酯主要代谢物3-苯氧基苯甲酸(3-PBA)的生成。蚯蚓富集结果表明，FEN在蚯蚓体内的含量先升高后降低，最大生物富集因子为0.3。亚急性毒性结果表明，高剂量（5 mg?kg-1）甲氰菊酯暴露14 d后，蚯蚓体内蛋白质含量显著降低（P<0.05），细胞色素P450（CYP450）、羧酸酯酶（CarE）、谷胱甘肽-S-转移酶（GST）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性和丙二醛（MDA）含量均显著增加（P<0.05），同时存在剂量效应，证实土壤中残留的FEN对蚯蚓具有毒性效应。本文对甲氰菊酯在土壤环境中的降解行为研究以及生态毒性风险评估具有重要的指导意义。     

甲氰菊酯在豌豆中残留动态及安全使用技术

采用气相色谱法及田间试验方法,研究了甲氰菊酯在豌豆中的残留消解动态,并对其安全使用技术进行试验。结果表明,甲氰菊酯在豌豆中原始沉积量因不同施药处理有较大的差别,施用量越大原始沉积量也越高;残留消解动态均符合一级动力学方程,不同施用量的降解速率基本相似,降解系数（︱k︱）=0.167 8±0.001 3,半衰期（DT₅₀）为4.1～4.2 d,降解99 %所需要的时间（T₉₉）为27.1～27.7 d。按常规方法施用甲氰菊酯有效成分5.00 g·（667 m²）^-1,施药1次或间隔7 d连续施药2次,末次施药后第14天的残留量均＜0.5 mg·kg^-1,第24天的残留量均＜0.1 mg·kg^-1,产品质量安全水平分别符合我国叶菜类蔬菜MRL和日本豆类蔬菜MRL的要求。     

气相色谱法测定甲氰·乐果20%乳油的研究

[目的]研究在同柱条件下甲氰.乐果20%乳油中乐果和甲氰菊酯分离测定方法,为企业生产的质量控制和质检机构质量检测提供参考。[方法]以5%OV-101色谱柱固定相,邻苯二甲酸正戊酯为内标物,利用FID检测器通过程序升温方法对甲氰.乐果20%乳油中2种组分进行气相色谱分离和测定。[结果]甲氰.乐果20%乳油中2种组分、杂质得到有效分离,乐果和甲氰菊酯的标准偏差分别为0.049、0.045;变异系数分别为0.30%、1.07%;回收率分别为99.43%~101.07%、99.50%~100.67%;线性相关系数分别为0.999 6、0.999 8。[结论]采用该方法测定甲氰.乐果20%乳油2种有效成分的质量分数,分离效果好,准确度、精密度高,线性关系好,符合定量分析要求。     

Resistance of beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) to endosulfan,organophosphorus and pyrethroid insecticides in Pakistan

Field populations of beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), from Pakistan were assessed for their resistance to the chlorinated hydrocarbon endosulfan, the organophosphates chlorpyrifos and quinalphos, and the pyrethroids cypermethrin, deltamethrin, bifenthrin and fenpropathrin. Using a leaf-dip bioassay, resistance to endosulfan was high during 1998–2000 but declined to very low, to low levels during 2001–2007, following a reduced use of the insecticide. Organophosphates and pyrethroids were consistently used over the past three decades, and the resistance had been increasing to these insecticide classes. Generally, the resistance to chlorpyrifos and pyrethroids remained low from 1998 to 2002–2003, but resistance increased to moderate to high levels from 2003–2004 to 2006–2007. For deltamethrin, resistance was very high during 2004–2007. Quinalphos resistance remained low during 1998–2006. Correlation analysis of LC₅₀ and LC₉₀ values showed a positive correlation between organophosphates and pyrethroids, but no correlation between endosulfan and organophosphates or pyrethroids tested herein. These results suggest that the conventional chemistries should be replaced with new chemistries for the successful management of S. exigua.     

低浓度甲氰菊酯对黄鳝乙酰胆碱酯酶活性的影响

[目的]了解甲氰菊酯对鱼类的毒副作用,为拟除虫菊酯类农药的污染监测提供参考。[方法]以低浓度甲氰菊酯（0.01、0.05、0.10、0.50、1.00μg/L）为供试药剂,采用接触染毒法研究不同作用时间下其对黄鳝肌肉乙酰胆碱酯酶（AChE）活性的影响。[结果]0.01μg/L甲氰菊酯对黄鳝肌肉AChE活性具有一定的诱导作用,随着甲氰菊酯浓度的升高,其对黄鳝肌肉AChE活性逐渐产生抑制作用,且其浓度越高对黄鳝肌肉AChE活性的抑制作用越强;连续暴露20d后,0.50、1.00μg/L甲氰菊酯处理组黄鳝肌肉AChE活性显著降低;随着染毒时间的延长,黄鳝肌肉AChE活性有逐渐降低的趋势。[结论]低浓度甲氰菊酯长时间处理可降低黄鳝肌肉AChE活性。     

辛硫磷甲氰菊酯及其混剂对土壤微生物的影响研究

采用密闭法,测定了辛硫磷、甲氰菊酯及其混剂对土壤微生物呼吸的影响,并对其进行了安全性评价。结果表明,辛硫磷和甲氰菊酯混合使用对土壤呼吸基本无影响。安全性评价认为甲氰菊酯、辛硫磷及其混剂对土壤微生物均属于低毒级或无实际危害级农药。     

Cloning of a sodium channel gene and identification of mutations putatively associated with fenpropathrin resistance in Tetranychus urticae

Tetranychus urticae Koch is the most serious mite pest to various orchard trees and garden plants. Biochemical and molecular analyses were conducted to elucidate resistance mechanisms in a fenpropathrin-resistant mite strain (FenR). No significant differences were found in the activities of carboxylesterase and glutathione-S-transferase between the susceptible (UD and PyriF) and FenR strains. Cytochrome P450 activity was highest in PyriF, followed by FenR and UD. Analysis of detoxification enzyme assays, therefore, suggested that metabolic detoxification plays little role, if any, in fenpropathrin resistance. However, the FenR strain showed approximately 104- and 33.3-fold slower knockdown responses than UD and PyriF strains, respectively, suggestive of sodium channel insensitivity as a major resistance mechanism. We cloned cDNA fragments of the para-homologous sodium channel α-subunit gene (Tuvssc) and determined its full-length nucleotide sequences. The complete open reading frame of Tuvssc was 6627 nucleotides, encoding 2209 amino acids. The amino acid sequences of Tuvssc were 47.5% and 51.2% identical to the fruit fly and varroa mite, respectively. Amino acid sequence comparison between the three strains revealed two mutations (L1022V and A1376D) and one deletion (HisDel^1278-1280) found only in FenR mites, among which the L1022V mutation was proposed to play a major role in knockdown resistance to fenpropathrin.     

甲氰菊酯对尼罗罗非鱼急性毒性和外周血细胞的影响

[目的]探究高效杀虫剂甲氰菊酯对尼罗罗非鱼急性毒性以及外周血细胞的影响。[方法]采用常温静水、体内染毒法对尼罗罗非鱼进行急性毒性试验,寇氏法计算半致死浓度（LC50）和安全浓度（SC）。根据96hLC50值,将尼罗罗非鱼暴露于0.4、0.6、0.8、1.0、1.5μg/L甲氰菊酯溶液中,分别在6、24、48、72、120、168h采血,常规法制作血涂片,观察测量红细胞形态,所有数据采用MicrosoftExcel2003进行分析。[结果]甲氰菊酯对尼罗罗非鱼幼鱼半致死浓度为5.90μg/L（96hLC50）,安全浓度为0.59μg/L。[结论]甲氰菊酯对尼罗罗非鱼有剧毒并能引起红细胞形态发生变化。尼罗罗非鱼对浓度为0.6～1.0μg/L甲氰菊酯溶液比较敏感,而且6～48h细胞形态变化比较大。     

Resistance Selection of Tetranychus cinnabarinus to Fenpropathrin and Genetic Analysis

The resistant inheritance mode of Tetranychus cinnabarinus to fenpropathrin were studied based on the resistance selection in laboratory. After 40 generations selection, T. cinnabarinus developed 68.5-fold resistance to fenpropathrin.The methods of cross and back-cross between resistant (R) and sensitive (S) strains were used for exploring the inheritance mode of the resistance of this mite to fenpropathrin. The log (Lc)-p equation of F1 got from obverse (SR) and reverse (RS)crosses was intermediate between S and R and inclined to S, the dominant indices DSR and DRS were -0.83 and -0.29,respectively, which indicated that the resistance is controlled by the incompletely recessive gene; the 95% confidence limit of this two dominant indices do not superpose showing DSR and DRS have significant difference and the maternal or external karyon effect may be existed in resistance inheritance; the back-cross results of heterozygote F1 with its parents suggested that the separation of progenies F2(SR()×S()and RS()×R())was cosistent with Mendel's single gene inheritance model.