两种昆虫生长调节剂对黑腹果蝇和斑翅果蝇的生物活性

为探讨昆虫生长调节剂氟铃脲和虱螨脲对黑腹果蝇Drosophila melanogaster和斑翅果蝇D.suzukii的毒性机制,采用室内生测法测定氟铃脲、虱螨脲对2种果蝇2龄幼虫的毒力,以及其在亚致死浓度LC_(10)、LC_(20)下对2种果蝇体内几丁质酶活性的影响。结果显示,经不同浓度的氟铃脲和虱螨脲处理后,随着时间的延长和浓度的增加,2种果蝇的死亡率均明显增加,氟铃脲处理可使2种果蝇的死亡率最高达到83.33%,明显高于虱螨脲处理后黑腹果蝇(65.00%)和斑翅果蝇(66.66%)的死亡率。亚致死浓度LC_(10)和LC_(20)的虱螨脲处理果蝇2龄幼虫24 h后,黑腹果蝇2龄幼虫体内的几丁质酶活性呈下降趋势,而斑翅果蝇2龄幼虫体内的几丁质酶活性则呈上升趋势。另外,亚致死浓度的氟铃脲可明显抑制黑腹果蝇体内几丁质酶的活性。表明昆虫生长调节剂氟铃脲和虱螨脲对果蝇有较强的毒力,氟铃脲的毒力高于虱螨脲,且果蝇体内几丁质酶的活性与氟铃脲和虱螨脲密切相关。     

温度和相对湿度对斑翅果蝇和黑腹果蝇飞行能力的影响

为研究不同温度和相对湿度对斑翅果蝇Drosophila suzukii与黑腹果蝇D. melanogaster飞行能力的影响,了解2种果蝇的飞行规律,利用26路昆虫飞行磨系统测试2种果蝇在不同条件下的总飞行距离、总飞行时间和平均飞行速度。结果表明,斑翅果蝇雌虫飞行的最适宜温度为18℃,总飞行距离达358.04 m,总飞行时间为3 082.68 s;雄虫更适宜在较高温度下飞行,当温度为30℃时,其总飞行距离和总飞行时间分别为171.37 m和3 075.89 s,且飞行速度较快。黑腹果蝇雌虫的飞行能力在30℃时最强,总飞行距离为702.77 m,雄虫的最适飞行温度是18℃和24℃。当相对湿度为75%时,斑翅果蝇雌虫的飞行能力最强,总飞行距离为262.10 m,总飞行时间也较长,为1 224.12 s,雄虫则在相对湿度44%时表现出较强的飞行能力;当相对湿度为58%时黑腹果蝇雌、雄虫的总飞行距离均达到最大,分别为554.30 m和514.47 m,此条件下雌、雄虫的总飞行时间也最长,分别为2 606.57 s和6 079.07 s。表明温度和相对湿度对2种果蝇飞行能力的影响存在差异,低温高湿条件有利于斑翅果蝇雌虫飞行,高温低湿条件下斑翅果蝇雄虫的飞行能力最强,高温中湿环境下黑腹果蝇的飞行能力较强,且黑腹果蝇的飞行能力总体上强于斑翅果蝇。     

沃尔巴克氏体感染对黑腹果蝇头部转录组的影响

为明确沃尔巴克氏体Wolbachia对果蝇神经行为影响的分子机制,采取转录组测序技术对感染沃尔巴克氏体和未感染的黑腹果蝇Drosophila melanogaster头部样本进行转录组测序、组装、注释,筛选感染沃尔巴克氏体wMel和未感染黑腹果蝇头部转录组间的差异表达基因,并选择差异表达基因中差异倍数较大或与神经行为相关的基因进行qPCR验证。结果表明,感染沃尔巴克氏体wMel和未感染黑腹果蝇头部差异表达基因有679个（差异倍数≥2,P<0.05）,其中,由于感染沃尔巴克氏体wMel而上调表达的基因有566个,下调表达的基因有113个。GO功能注释分析显示,差异表达基因与代谢过程、催化和结合功能相关。KEGG通路注释分析发现,差异表达基因主要富集在蛋白消化与吸收、内分泌、神经活性配体-受体互作以及激素合成等通路中。从差异表达基因中筛选出11个基因进行qPCR验证,有9个基因的表达趋势与RNA测序结果一致。表明沃尔巴克氏体可广泛影响果蝇头部基因的表达水平,暗示可能由此影响宿主的神经行为。     

Regulation of insecticide resistance-related cytochrome P-450 expression in Drosophila melanogaster

Two protein bands, resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, account for most of the cytochrome P-450 in Drosophila melanogaster. P-450-A is ubiquitous among strains tested; whereas P-450-B is unique to certain strains. Dimethylnitrosamine demethylase activity is associated with P-450-B. Biochemical and genetic analyses showed that genes located on chromosome II were required for P-450-B expression. These genes were mapped within an interval that includes a major insecticide-resistance locus. Regulatory loci on chromosome III were required for maximum expression of P-450-B. One of these regulatory loci was mapped at another major resistance locus on chromosome III. There was a good correlation between P-450-B expression and resistance to phenylurea among the different strains tested. These results indicate that Drosophila can be a useful model to study the molecular mechanisms of insecticide resistance.     

Expression of genes related to Parkinson’s disease after paraquat treatment in Drosophila melanogaster

This study was designed to determine the minimum effective concentration of paraquat that modulated the expression of PKD-related genes in Drosophila. We first studied the viability of Drosophila and then tested the expression of the PKD-related genes—Parkin, UCH, and tau—in various concentrations of paraquat in the water sucked by Drosophila. The lowest effective concentration of paraquat was approximately 20 μM and the gene expression was induced at paraquat doses between 20 mM and 20 μM. Parkin and tau expression was inhibited, while that of UCH was significantly increased.Next, we examined the expression of the Parkin and UCH genes in the neurons of SOD-reduced mutants under oxidative stress conditions and found that Parkin was up regulated, while UCH was down regulated. We also found that the expression of Parkin was regulated by JNK. This study revealed that paraquat affects the expression of PKD-related genes via oxidative stress.In conclusion, our results showed that paraquat in the water sucked by Drosophila altered the gene expression at a minimum concentration of 20 μM, and that it not only promoted but also inhibited PKD-related gene expression via signal transduction mediated by oxidative stress. In order to confirm whether paraquat is a causal factor of PKD, more balanced and in-depth tests seem to be done looking into multiple aspects.     

Insecticide Resistance in Field Strains of Pectinophora gossypiella (Saunders) in China and Effect of Synergists on Deltamethrin and Parathion-methyl Activity

Filter-paper residual toxicities of some insecticides used extensively in China were determined during 1994 using newly hatched (within 30 min) larvae of four Pectinophora gossypiella (Saunders) strains. The strains were field collections collected in the Yangtze River cotton-belt areas. Compared with the susceptible laboratory strain from Qunli (Lishui County, Jiangsu province), the four field strains from Anqing (Anhui province), Jiangling (Hubei province), Cixi(Zhejiang province) and Tongzhou(Jiangsu province) had developed 185-, 6·7-, 698- and 249-fold resistance, respectively, to deltamethrin. Cixi and Tongzhou field strains had also developed 103- and 94-fold resistance to fenvalerate, and 10- and 3·6- fold resistance to parathion-methyl. Percentage of survivors at diagnostic dosage for deltamethrin showed that the strains from Anqing, Jiangling, Cixi and Tongzhou had 87·2, 18·3, 90·1 and 74·6% resistant individuals respectively. Cixi and Tongzhou field strains had 88·9 and 65·3% resistant individuals after application of parathion-methyl, which was consistent with the corresponding resistance ratios. Studies of the effect of synergists piperonyl butoxide (PBO), triphenyl phosphate (TPP) with deltamethrin and parathion-methyl in Cixi, Anqing and Tongzhou field strains suggested that metabolic resistance mechanisms such as carboxylesterases (CarE) and mixed function oxygenases (MFO) were involved in parathion-methyl resistance, but not in deltamethrin resistance. © 1997 SCI.     

果树新害虫叔白颜果蝇Drosophila triauraria在山东省的发生规律

正果蝇属双翅目果蝇科果蝇属昆虫,多数种类仅以腐烂果实为食物,少数可为害健康果实。已报道的为害多种水果的果蝇有斑翅果蝇Drosophila suzukii、黑腹果蝇D. melanogaster等(任路明等,2014)。2017年用装有糖醋酒液的诱捕器在山东省烟台市、泰安市、济南市、日照市4个市的樱桃园和葡萄园收集果蝇,调查发现一种新的果蝇——叔白     

溴氰菊酯乳油急性中毒原因分析

溴氰菊酯乳油急性中毒除与溴氰菊酯本身毒性有关外．还可能与该乳油中有机溶剂二甲苯有关。     

Resistance to fenarimol in Nectria haematococca var. cucurbitae

Genetic work with 51 fenarimol-selected strains of Nectria haematococca var. cucurbitae identified a polygenic system for resistance with at least nine chromosomal loci involved. The mutant genes, designated fen-1 to fen-9, gave low levels of resistance to fenarimol and to three other C-14 demethylation inhibiting (DMI) fungicides, namely triforine, imazalil, and triadimenol. Haploid strains carrying two fen mutations exhibit higher levels of resistance, indicating additivity of gene effects. All fen mutations appear to be pleiotropic, having more or less adverse effects on growth, sporulation, spore germination, pathogenicity, and tolerance of somewhat high temperatures. Accumulation of fenarimol in resistant strains was lower than in the wild type, suggesting that fen mutations code for a common resistance mechanism based on a permeability barrier. Various inhibitors of energy generation increased the accumulation level, indicating that accumulation is energy dependent and may be the result of passive influx and energy-dependent efflux. Lower accumulation in resistant strains is probably the result of increased efflux, as has been found with other fungi. A double mutant carrying the mutations fen-7 and fen-9 showed lower accumulation of fenarimol than a strain carrying the fen-7 only, indicating additivity of effects in this regard also.     

氟虫腈与斑马鱼GABA_A及果蝇RDL受体作用的差异性研究

采用同源建模的方法构建了斑马鱼γ-氨基丁酸A型(GABA A)受体和果蝇RDL(resistance to dieldrin)受体跨膜区的三维结构,研究了氟虫腈在两个受体中作用位点的差异;采用分子对接和分子动力学方法,探讨了氟虫腈与斑马鱼GABA A受体和果蝇RDL受体的结合模式,并比较了氟虫腈与两个受体作用的差异性。结果表明:斑马鱼GABA A受体和氟虫腈作用位点的结构与果蝇RDL受体和氟虫腈作用位点的结构存在一定的差异,果蝇RDL受体中的Ala301对应斑马鱼GABA A受体α1亚基中的Val284和γ2亚基中的Ser306,氨基酸构象的差异较大;氟虫腈与斑马鱼GABA A受体的结合位点靠近胞内区一端,而与果蝇RDL受体的结合位点则位于受体第二跨膜区的Ala301~Leu308区域内。复合物分子动力学模拟结果表明,在模拟过程中,两个受体与氟虫腈复合物体系的势能可很快达到平衡状态。斑马鱼GABA A受体与氟虫腈之间形成4个氢键,其中概率大于60%的氢键有2个;而尽管果蝇RDL受体与氟虫腈形成了6个氢键,但只有1个氢键的概率大于50%,其复合物结合的稳定性比前者低。     

小麦田大穗看麦娘对精噁唑禾草灵的抗性

为明确小麦田大穗看麦娘对精噁唑禾草灵的抗性水平及产生抗性的机理,采用整株法测定了河南省小麦田大穗看麦娘种群对精噁唑禾草灵的抗性水平,以及细胞色素P450s抑制剂胡椒基丁醚(PBO)对精噁唑禾草灵的增效作用,并通过基因测序技术研究了其靶标ACCase基因的突变位点。结果显示:与敏感种群HN-06相比,抗性种群HN-05对精噁唑禾草灵的抗性倍数为52.2,其ACCase基因存在Ile-2041-Asn和Gly-2096-Ala位点突变;喷施PBO后,精噁唑禾草灵对大穗看麦娘的GR50值(有效成分)为5.4 g/hm^2,表现出明显的增效作用,与未喷施PBO处理的差异倍数为161.3。研究表明,抗性种群HN-05对精噁唑禾草灵已产生高水平抗性,该抗性的产生可能是由于其靶标基因突变和P450s介导的代谢增强同时导致的,即表现出了靶标抗性和非靶标抗性共存的现象。     

番茄灰霉病菌对嘧霉胺的抗药性

2001年从辽宁省不同地区的保护地中采集番茄灰霉病果或病叶，经单孢分离共获得番茄灰霉病菌70株。采用菌丝生长速率法测定了其对嘧霉胺的敏感性。结果表明，番茄灰霉病菌已对嘧霉胺产生中等水平抗药性，抗性频率为20．0％。经室内药剂诱导获得了高抗菌株，抗性倍数最高达35．7倍。嘧霉胺与多菌灵及嘧霉胺与速克灵间不存在交互抗药性。野生抗性菌株具有较好的遗传稳定性，连续转接9次后抗药性无明显下降。不同菌株的菌丝生长速度、鲜重和渗透敏感性存在显著差异，但该差异与灰霉病菌对嘧霉胺的敏感性无相关性。抗性菌株与敏感菌株具有同样的致病能力。     

Genetic analysis of abamectin resistance in Tetranychus cinnabarinus

The carmine spider mite is the most serious crop mite pests in China. Abamectin has been used to control insects and mites worldwide but carmine spider mites, Tetranychus cinnabarinus, had developed resistance to it. Genetic research on insecticide resistance has been fundamental for understanding the resistance development, studying resistance mechanisms, and designing appropriate resistance management strategies to control insect pests. A resistant colony of T. cinnabarinus, RRG42, was established to examine the inheritance of abamectin resistance in T. cinnabarinus. The females of T. cinnabarinus were selected for bioassay using a slide dip method. After 42 generations of selection, the RRG42 strain was 8.7-fold resistant to abamectin compared with the susceptible strain (SS). The logarithm (log) concentration–probit response curve for F₁s from reciprocal crosses, of F₁RS and F₁SR, were inclined to that for SS and the degree of dominance (D) values for F₁s were −0.81 and −0.17. There was a significant difference in values of LC₅₀ and slope of log concentration–probit lines between F₁RS and F₁SR. The observed mortalities of BC1 (F₁RS♀ × RRG42♂) and BC1′ (F₁SR♀ × SS♂) were significantly different from the expected mortalities based on a monogenic resistance in the chi-square tests. The inheritance of abamectin resistance in T. cinnabarinus is incompletely recessive and may be controlled by more than one gene. The maternal or cytoplasmic effect may exist in the inheritance of resistance to abamectin in T. cinnabarinus.     

2017年褐飞虱和白背飞虱田间种群对氟吡呋喃酮的抗性监测

氟吡呋喃酮是拜耳作物科学公司开发的一种新型新烟碱类杀虫剂。为探究氟吡呋喃酮在水稻稻飞虱上的应用前景,采用稻苗浸渍法测定了采自中国7省10地的褐飞虱田间种群和5省8地的白背飞虱田间种群对氟吡呋喃酮的抗性。结果表明:10个地区的褐飞虱田间种群对氟吡呋喃酮表现为低等至中等水平抗性(抗性倍数RR=6.1~17.4),其中江西南昌、河南信阳、安徽六安和浙江杭州种群表现为中等水平抗性(RR=10.1~17.4);相反,白背飞虱除湖北孝感田间种群对氟吡呋喃酮表现为低水平抗性(RR=6.3)外,其他7个地区的田间种群均保持敏感(RR=1.1~3.6)。本研究揭示了中国褐飞虱和白背飞虱田间种群对氟吡呋喃酮的敏感性现状,可为合理应用氟吡呋喃酮防控稻飞虱提供理论依据。     

柑橘叶点霉属(Phyllosticta spp.)真菌的遗传多样性分析

利用筛选的11条ISSR引物对从我国柑橘主产区和国外收集的135株叶点霉属真菌菌株进行扩增,扩增产物进行凝胶电泳,扩增图谱用NTSYS-pc2.10软件进行群体聚类分析。结果显示,共扩增出116个DNA条带,其中多态性位点为112个,多态率为96.55%;平均每个引物可以扩增出10.55个条带,扩增产物大小在250~3 000 bp。聚类分析显示,中国柑橘叶点霉属真菌可以分为4个种,即P.citricarpa、P.citriasiana、P.capitalensis和P.citrichinaensis。以遗传相似性系数0.97为阈值时,柑橘黑斑病病原菌(P.citricarpa)种群可分为5个亚类,subclade-I的菌株来自中国的本地早、温州蜜柑、槾橘和南丰蜜橘,subclade-II的菌株均来自中国的砂糖橘,subclade-III的菌株来自非洲莫桑比克柠檬和葡萄柚、佛罗里达甜橙、南非甜橙和来自杭州市场上进口的澳橘,subclade-IV的菌株来自中国的甜橙,subclade-V的菌株来自中国的柠檬,表明我国柑橘黑斑病病原菌具有丰富的遗传变异,其遗传变异与寄主相关;我国与国外的柑橘黑斑病病原菌在起源上可能存在差异。P.citriasiana、P.capitalensis和P.citrichinaensis种群内也存在遗传变异,但其遗传变异与地理分布和寄主未发现相关性。该研究结果为研究柑橘叶点霉属真菌的遗传多样性奠定了基础。     

浙江省果蔬灰葡萄孢对啶酰菌胺的抗性

以2004—2006年从浙江、江苏等地采集的灰葡萄孢对啶酰菌胺的敏感性基线[EC₅₀ = (1.07 ± 0.11) mg/L]为依据,采用菌丝生长速率法连续监测了浙江省果蔬灰葡萄孢群体对啶酰菌胺的敏感性变化。结果表明:浙江省果蔬灰葡萄孢对啶酰菌胺的抗性发展迅速,2012—2013年和2017—2018年的平均EC₅₀值分别为 (5.23 ± 7.79) 和 (24.30 ± 49.33) mg/L。其中,2012—2013年的抗药性菌株频率为15.3%,且均为低水平抗性 (LR) 菌株;而2017—2018年的抗药性频率上升至53.2%,并出现了7.5%的中等水平抗性 (MR) 菌株和1.3%的高水平抗性 (HR) 菌株。啶酰菌胺抗性菌株的菌丝生长速率、产孢量、产菌核数和致病力与敏感菌株相比均无显著差异。抗药性分子机制研究表明:啶酰菌胺抗性菌株的琥珀酸脱氢酶B亚基 (SDH B) 均发生了点突变,共包括H272R、P225F和N230I 3种类型,其中H272R型突变占88.5%;其SDH A和SDH D均未发生点突变;而SDH C的突变 (G85A + I93V + M158V + V168I) 与对药剂敏感性之间无明显联系。     

西双版纳自然保护区球孢白僵菌的遗传多样性

为了解西双版纳自然保护区球孢白僵菌Beauveria bassiana的遗传多样性,采用SSR分子标记技术对西双版纳自然保护区的240株球孢白僵菌的遗传结构、基因流、菌株分化以及遗传变异相关性进行了测定和分析。结果表明,9条引物扩增240株球孢白僵菌菌株多态位点数为77个,多态位点比率为97.40%。采集的240株球孢白僵菌的总体等位基因数、有效等位基因数、Nei’s基因多样性指数和Shannon信息多样性指数分别为1.97、1.31、0.18和0.29。从寄主居群来看,鞘翅目昆虫球孢白僵菌群体遗传多样性最高,螳螂目最低,其Nei’s基因多样性指数和Shannon信息多样性指数分别为0.20和0.30、0和0;总遗传变异的29.27%存在于寄主居群间。从生境水平来看,五十五生境中球孢白僵菌群体遗传多样性最高,丫口寨生境中最低,其Nei’s基因多样性指数和Shannon信息多样性指数最高分别为0.19和0.31、0.06和0.09;总遗传变异的14.92%存在于生境居群间。从季节水平来看,球孢白僵菌秋季居群的遗传多样性最高,夏季最低,其Nei’s基因多样性指数和Shannon信息多样性指数分别为0.20和0.32、0.17和0.26;总遗传变异的3.45%存在于季节居群间。表明西双版纳自然保护区球孢白僵菌在寄主昆虫、生境分布和季节间存在明显的遗传多样性,与寄主昆虫类群的关系密切。     

Biological, biochemical, and molecular parameters of Helisoma duryi snails exposed to the pesticides Malathion and Deltamethrin

Aquatic environments get contaminated with pesticides residues that result from the application of pesticides in agricultural practices. The present study aimed to evaluate the pesticides Malathion and Deltamethrin on biological and biochemical parameters of Helisoma duryi snails. The results showed that LC₁₀ of the two pesticides caused considerable reduction in survival rates and egg production of treated snails. Glucose concentration in hemolymph of the exposed snails showed a significant increase. On the other hand, albumin in hemolymph and glycogen contents as well as the activities of enzymes in tissues of snails including lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), arginase, and ornithine aminotransferase (OAT) were significantly inhibited. Meanwhile, the activity of AMP deaminase of the exposed snails was significantly increased in the hemolymph in response to treatment. The electrophoretic pattern of total protein showed differences in number and molecular weights of protein bands. DNA concentration was investigated by measuring the intensity of the genomic bands and its showed its increase in the treated snails. It was concluded that the residues of Malathion and Deltamethrin pesticides in aquatic environments have toxic effects on non-target organism, e.g. H. duryi snails.     

Genetic Diversity of Japanese Strains of Ralstonia solanacearum

ABSTRACT The genetic diversity of 74 Japanese strains of Ralstonia solanacearum was assessed by pathogenicity tests and the repetitive sequencebased polymerase chain reaction (rep-PCR) fingerprint method. Based on their genomic fingerprints, biovar N2 strains were divided into two distinct groups, one consisting of potato isolates belonging to race 3, and the other consisting of tomato, eggplant, pepper, and tobacco isolates belonging to race 1. Biovar 3 strains had low average similarity and were divided into five groups that differed in original host or pathogenicity. Biovar 4 strains consisted of only one group at the 80% similarity level. Comparative analysis of the rep-PCR fingerprints of 78 strains, including six biovars from Japan and various countries, revealed two main clusters. Cluster 1 comprised all biovar 3, 4, and 5 strains, biovar 1 strains from Reunion, and some biovar N2 strains from Japan. Cluster 2 included most of the biovar 1, 2, and N2 strains. The fingerprints showed low average similarity with biovar N2 strains from Japan and Brazil.