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1.
室内恒温条件下以人工饲料饲养的嗜卷书虱 Liposcelis bostrychophila Badonnel成虫,分别在35%和55%CO_2。(21%O_2,N_2作为平衡气体使用)组配的气调环境中以70%的选择压力处理,以选育其抗高CO_2气调性。选育至30代获得抗性品系HCC_1和HCC_2,以LT_50为标准,其抗性倍数分别达4.6和5.3倍。整个选育过程中,气调暴露时间对数值与死亡率机率值间的回归直线基本平行,且斜率值均低于敏感基线的斜率值,这表明嗜卷书虱对高CO_2抗性发展的基因潜能至第30代仍未耗尽。两个抗性品系的抗性均不太稳定,去除选择压力后抗性显著下降,且两抗性品系均具有繁殖不利性即适合度缺陷。以净增值率为指标衡量,HCC_1和HCC_2相对于敏感品系分别具有0.52和0.45的适合度。  相似文献   

2.
利用微丝(microfilament,MF)解聚药物细胞松驰素B(cytochalasinB,CB)处理G_0期小鼠C_3H_(10)T_(1/2)成纤维细胞,对G_0至S期DNA合成,胸腺嘧啶核苷激酶(thymidinekinase,TK)活性、TK基因表达、钙调素(calmodulin,CaM)水平和一些细胞周期早期基因的表达进行了观察,G_0期细胞经3mg/LCB处理2h,促MF解聚增强了血清对S期细胞TK活性、TK基因表达和DNA合成的刺激作用,并促进细胞提前进入S期.血清刺激G_0期细胞进入晚G_1期和S期时,CaM水平明显升高,而CB预处理则使CaM含量进一步增加,特别是CB处理促使S期CaM增加向核内转移.CB处理明显增强血清对c-jun、c-fos和c-myc基因表达的刺激作用,而PKC抑制剂H_7则抑制CB处理对这些基因转录的刺激作用,说明CB使G_0期细胞MF解聚刺激c-jun、c-fos和c-myc的转录活性与PKC的作用有关.结果表明G_0至S期早期MF的重组可促进细胞进入S期,增强DNA合成.  相似文献   

3.
用氰戊菊酯对来自阳谷的棉铃虫(YG)Heliothisarmigera(Hubner)进行抗性品系的筛选。在15代期间经过9代的室内选育,获得抗性品系(Fen-R),抗性倍数高达2463倍,筛选后F1,代LD50值(24.1412g/头)比筛选前F1代LD50值(0.2020 g/头)提高了119.5倍。对来自偃师的棉铃虫(YS)进行了连续两代单对筛选,得到敏感品系(Fen-S),敏感品系的LD50值为0.0116g/头,接近1983年东台敏感品系的LD50值(0.0098g/头)。Fen-R抗性品系筛选前后分别测定了七种杀虫剂的剂量-死亡回归线,发现Fen-R抗性品系对溴氰菊酯[LD50(Fen-R)LD50(YG)=5.2X]和氯氰菊酯(2.5X)具有一定程度的交互抗性;而对功夫菊酯(0.66X),氯菊酯(0.87X)、灭多威(0.74X)及久效磷(1.5X)没有交互抗性。氰戊菊酯加Pb的增效试验结果表明棉铃虫对氰戊菊酯的抗性主要是由于多功能氧化酶的代谢作用。毒理学资料还暗示抗性为多因子(基因)的。  相似文献   

4.
几种因子对丛粒藻株A的效应   总被引:12,自引:1,他引:11  
王修垣  谢树华   《微生物学通报》1996,23(5):275-277
研究了温度、NaF和细菌对丛粒藻(BotryococcusbrauniiKutz.)纯培养物A的效应。该藻最适生长温度为25℃。NaF0.1mg/L促进该藻生长。该藻与棒杆菌协同培养可提高产烃量,由无菌对照的0.089g/L提高到0.392g/L,总烃水平由56%提高到24.2%。  相似文献   

5.
毒死蜱对家白蚁毒杀作用的时间与剂量效应   总被引:2,自引:0,他引:2  
用含不同毒死蜱浓度的毒土对家白蚁(Coptoternes foumosamus Shiraki)进行了生物测定,浓度范围为0.015-0.48mg/kg。观察2周。实验观察发现土壤中毒死蜱浓度为0.48-0.06mg/kg时,白蚁接触毒土出现的死亡高峰为4小时至2天;在0.03mg/kg时,死亡高峰在1周以后;而浓度为0.015mg/kg时,2周内仍观察不到白蚁死亡。所获的生物测定数据很好地拟合时  相似文献   

6.
香椿的组织培养和玻璃苗的防止   总被引:2,自引:0,他引:2  
1植物名称香椿(Toonasinensis)。2材料类别(1)种子发芽3~5d后的下胚轴及带少许下胚轴的子叶;(2)当年生半木质化的腋芽茎段。3培养条件芽诱导及增殖培养,以MS为基本培养基,蔗糖30g·L~(-1),琼脂0.5%,附加激素(单位mg·L~(-1)):(1)6-BA0.2;(2)6-BA0.2、GA_32.0;(3)IAA0.1、6BA0.2;(4)ZT0.2、GA_32.0。诱导生根培养基为1/ZMS或仅含MS有机质(铁盐减半),附加1.0mg·L~(-1)IBA、15g·L~(-1)…  相似文献   

7.
亚麻下胚轴离体培养和转化的研究   总被引:6,自引:0,他引:6  
报道了亚麻(Linum usitatissimum)的高频率植株再生和细胞转化。亚麻下胚轴切段培养在MSB分化培养基上,诱导分化出不定芽。最佳的激素组合是BA2mg/L+IAA0.5mg/L,分化频率可达97%。在附加BA1mg/L和NAA0.02mg/L的MSB培养基上,亚麻下胚轴外植体的不定芽分化频率也可达90%以上。用根癌农杆菌(Agrohacterium tumefaciens)感染亚麻下胚轴外植体,在含卡那霉素50mg/L的选择培养基上筛选获得卡那霉素抗性苗,并检测到GUS基因活性表达。表明它们是转化植株,转化频率约为2%。  相似文献   

8.
墨兰的无菌播种和植株再生   总被引:9,自引:0,他引:9  
墨兰的无菌播种结果发现,在不添加细胞分裂素的培养基上,种子可以发芽,但只有原球茎和根状茎产生,不可能进一步分化成苗,只有在含有不同激素成分MS或KnudsonC培养基上,才有可能诱导芽的分化,其中以附加6-BA0.5-1.0mg/L_NAA0.1mg/L诱导效果最佳,在附加6-BA2.0mg/L+NAA0.4mg/L的MS培养基中,能加速芽的增殖,根状茎转入含有相同激素成分的液体增殖培养基中振荡培  相似文献   

9.
海边香豌豆胚性愈伤组织的诱导和体细胞胚发生   总被引:2,自引:0,他引:2  
将生长14d的海边香豌豆(Lathyrus maritimus(L.)Bigel)无菌苗下胚轴切成0.5cm左右的片段,置于含有1mg/L2,4-D,0.5mg/L BA和0.5%NaCl的MS培养基中,28d后诱导出胚性愈伤组织。将其转入含有适当浓度2,4-D的MS培养基上,又28d后可得到大量球形胚和心形胚以及极少量鱼雷胚和子叶胚。诱导体细胞胚适合的2,4-D浓度为0.5mg/L。较高浓度的2  相似文献   

10.
荷兰鸢尾(Iris xiphium L. var. hybridum)的组织培养   总被引:1,自引:0,他引:1  
取荷兰鸢尾(IrisxiphiumL.var.hybridum)鳞茎片不同部位外植体块,接种于附加不同激素配比的基本培养基上,其中取自鳞茎片基部外植体块2mm×2mm×2mm,培养基为MS+BA1.0mg/L+NAA0.2mg/L的不定芽诱导率为最高(70%);最理想的增殖培养基为MS+BA2.0mg/L+NAA0.2mg/L。不定芽直径4~5mm,培养基为MS+BA0.2mg/L+NAA0.5mg/L有利于不定根的发生,诱导生根率达833%。试管苗不经练苗可直接出瓶,移栽于泥炭∶田土∶河沙=1∶1∶1(V/V)的基质中。  相似文献   

11.
Jinfu Wang 《Insect Science》1999,6(3):271-276
Abstract The stability of resistance in the organophosphate resistant strain of Culex pipiens pallens with amplification of single gene coding for esterase B2 was determined under relaxation of insecticide selection. Insecticide resistance and amplification of esterase were both lost when strains were not homozygous for the presence of amplified gene, probably due to biological disadvantage of the esterase gene. LC50 and LC95 of chlorpyrifos for this strain were 0. 2099 mg/L and 0.9036 mg/L in the F0 generation respectively, but 0. 0207 mg/L and 2. 8027 mg/L respectively in the F16 generation. In the homozygous strain, insecticide resistance was still stable and amplification of esterase remained after 16 generations under relaxation of insecticide selection, which indicated that copy of esterase gene was not lost in the offspring of this strain. The evolution of insecticide resistance in mosquitoes is discussed.  相似文献   

12.
淡色库蚊酯酶等位基因及其在自然种群中的频率分布   总被引:6,自引:0,他引:6  
酯酶基因扩增所产生的酯酶活性升高是库蚊Culex pipiens对有机磷杀虫剂抗性的主要机理之一。采用分子杂交技术和限制性酶切片段长度多态性(RFLP)分析,已鉴定出多种酯酶等位基因类型。该文通过酯酶基因特异性片段的PCR扩增及扩增片段的酶切片段分析,对淡色库蚊Culex pipiens pallens四种有机磷抗性品系的酯酶等位基因进行分型,并测定分析自然种群中不同酶型的频率分布。研究结果表明:PCR分型方法具有快速、准确的特点。不同的有机磷杀虫剂对酯酶等位基因具有明显的选择作用。双硫磷品系为B1型;毒死蜱和敌百虫品系为B2型;马拉硫磷品系为B1型和B1/B2杂合型。不同地区采集的种群表现出不同的酶型频率分布。该文就杀虫剂对酯酶等位基因选择作用及自然种群的酶型频率分布进行了讨论。  相似文献   

13.
抗溴氰菊酯家蝇在不同用药方式下的敏感性变化及其机制   总被引:3,自引:0,他引:3  
邱立红  李学锋 《昆虫学报》1999,42(3):248-256
以具有极高抗水平的抗溴氰菊酯家蝇Musca domestica vicina Macquart DR0品系为试虫,模拟田间几种常见的用药方式(混用、轮用、使用增效剂),在室内进行平行汰选,并以不用药和继续用原药汰选的为比较,研究试虫在这几种用药方式下的敏感性变化及其变化机制。抗性家蝇用辛溴混剂、辛硫磷以及溴氰菊酯+SV1汰选后,在F16(F17)代以前,对溴氰菊酯及汰选药剂的抗性发展相对都比较缓慢;F16(F17)代以后,用溴氰菊酯+SV1汰选的家蝇对溴氰菊酯的敏感性迅速下降,抗性发展很快。家蝇对溴氰菊酯的敏感性变化与药剂中溴氰菊酯的选择压有关。生化分析结果表明,在不同用药方式汰选下,家蝇体内酯酶、多功能氧化酶、谷胱甘肽-S-转移酶、乙酰胆碱酯酶的酶活或特性发生了不同的变化。  相似文献   

14.
J. A. McKenzie  A. G. Parker    J. L. Yen 《Genetics》1992,130(3):613-620
Following mutagenesis with ethyl methanesulfonate, selection in a susceptible strain with a concentration of the insecticide diazinon (0.0004%, w/v) above that required to kill 100% of the susceptible strain, the LC100 of that strain, resulted in a single gene response. The resultant four mutant resistant strains have equivalent physiological, genetical and biochemical profiles to a diazinon-resistant strain derived from a natural population and homozygous for the Rop-1 allele. Modification of the microsomal esterase E3 is responsible for resistance in each case. The Rop-1 locus maps approximately 4.4 map units proximal to bu on chromosome IV. Selection within the susceptible distribution, at a concentration of diazinon [0.0001% (w/v)] less than the LC100, resulted in a similar phenotypic response irrespective of whether the base population had been mutagenized. The responses were polygenically based, unique to each selection line and independent of Rop-1. The relevance of the results to selection for insecticide resistance in laboratory and natural populations is discussed.  相似文献   

15.
It has been proposed that amplification of genes for esterase that provide resistance to insecticides may originate from transposition events. To test this hypothesis, we have constructed a minigene coding for a soluble acetylcholinesterase under the control of a nontissue-specific promoter (hsp70). When introduced into Drosophila, the gene is expressed in all tissues and the extra acetylcholinesterase produced confers a low level of insecticide resistance (twofold). The minigene was mobilized by crossing the initial transformant with a strain providing a source of P-element transposase. After 34 generations of exposure to the organophosphate parathion, we obtained a strain with a higher resistance (fivefold). This strain had only one extra Ace gene, which overexpressed acetylcholinesterase. Thus, following transposition, resistance resulted from the overexpression of a single copy of the gene and not from gene amplification. Received: 9 August 1996 / Accepted: 27 May 1997  相似文献   

16.
杭州地区尖音库蚊复合组的抗药性动态   总被引:1,自引:0,他引:1  
崔峰  寇宇  乔传令 《昆虫知识》2006,43(1):78-81
用生物测定和淀粉电泳技术对采自杭州市和上海市的尖音库蚊复合组(Culex pipienscomplex)蚊虫的抗性水平及与抗性有关的酯酶进行了研究。抗性水平的测定结果表明:与S-LAB敏感系相比,杭州市种群对DDVP、对硫磷、毒死蜱、邻仲丁基苯基甲基氨基甲酸酯和残杀威的抗性分别是S-LAB敏感品系的3.9,7.6,1.6,1.6,2.5倍。利用淀粉凝胶电泳技术分析了野生种群中抗性羧酸酯酶(EST)等位酶的基因表型及其频率。4个种群中都存在着世界范围内广泛分布的过量产生的非特异性酯酶Estβ1和Estα2/β2,上海种群主要以高活性的酯酶Estβ11为主(98.3%),除了这些基因以外,2004年杭州市下城区又出现了1种新的酯酶基因(50%)。  相似文献   

17.
Vector control programmes in many countries face the dual problems of parasite drug resistance and insecticide resistance in the insect vectors of the disease. Here we report for the first time a new esterase-based insecticide resistance mechanism in the filariasis vectorCulex quinquefasciatus.The field collected COL strain ofC. quinquefasciatusfrom Columbia was heterogeneous for organophosphorus insecticide resistance. On native polyacrylamide gels it had an elevated β-naphthyl acetate specific esterase with the same Rfas that for the Estβ1s involved in insecticide resistance in other strains of this mosquito species. After five generations of temephos insecticide selection, both the esterase specific activity withp-nitrophenyl acetate and the temephos LC50values were increased, suggesting that elevation of esterase activity was the underlying mechanism of resistance. Western blots with antisera raised to Estα21and Estβ21fromC. quinquefasciatusindicated that the COL strain had an elevated Estα3 enzyme which co-migrated on native gels with Estβ1. Southern blots indicated that anestα3gene was amplified in the COL strain and a Cuban mosquito strain (MRes), although the restriction digest patterns of theestβ1 genes in these two strains are different. In contrast, the Californian TEMR strain, with the amplifiedestβ11gene, had no associated elevated Estα.Restriction digest patterns for COL and TEMR DNA suggest that they contain an identicalestβ11gene, but our data suggest that theestα3gene occurs on the same amplicon as anestβ1 gene although the genes are probably >10 kb apart. Hence, either the COL strain has twoestβ1genes or theestβ11amplicon in TEMR has been disrupted at some stage during the long colonisation of this strain and the amplifiedestα has been lost.  相似文献   

18.
The esterase-based insecticide resistance mechanisms characterised to date predominantly involve elevation of activity through gene amplification allowing increased levels of insecticide sequestration, or point mutations within the esterase structural genes which change their substrate specificity. The amplified esterases are subject to various types of gene regulation in different insect species. In contrast, elevation of glutathione S-transferase activity involves upregulation of multiple enzymes belonging to one or more glutathione S-transferase classes or more rarely upregulation of a single enzyme. There is no evidence of insecticide resistance associated with gene amplification in this enzyme class. The biochemical and molecular basis of these two metabolically-based insecticide resistance mechanisms is reviewed.  相似文献   

19.
An Italian organophosphate-resistant strain ofCulex pipiens (Lucca) was found to be polymorphic for elevated and nonelevated esterases. Selection for high esterase activity produced a strain homozygous for elevated esterases A2 and B2. Selection for low activity produced a strain homozygous for nonelevated esterases, A4i and B1i. Crossing experiments showed that A2 and B2 are coded by separate but closely linked genes, as are A4i and B1i. Results indicate that elevated A2 and nonelevated A4i are alleles of a single gene (Est-3 locus), as are elevated B2 and nonelevated B1i (Est-2 locus). Selection for electromorph variants gave four elevated A variants and three elevated B variants. These esterases were not selected in the field. In Lucca, A2 and B2 replaced A1, suggesting a selective advantage to the former over the latter in the presence of chlorpyrifos. It is hypothesized that the degree of amplification is an important factor in the selection of a particular esterase electromorph as a resistance mechanism and that migrating individuals with amplified genes could have an advantage when invading a population under selection.  相似文献   

20.
敌百虫对水丝蚓的毒害   总被引:14,自引:0,他引:14  
采用急性毒性方法测定了被不同浓度敌百虫毒害的水丝蚓(Limnodilus hoffineisteri)半致死浓度(LC50),利用测定酶活性方法检测了水丝蚓超氧化物歧化酶(SOD)的变化及中毒后水丝蚓喂饲的强壮水螅(Hydra robusta)SOD的改变。(1)敌百虫对水丝蚓48 h LC50为3.29 mg/L。敌百虫对水丝蚓SOD活性影响显著(P<0.05):在低浓度1~4 mg/L时,SOD活性呈上升趋势,但随浓度增加至5 mg/L,SOD活性开始下降。(2)用1~8 mg/L中毒后的水丝蚓依次喂饲水螅,SOD活性呈上升趋势。实验结果表明,敌百虫作为重要的杀虫剂或作为防治鱼病的药物,对水丝蚓造成胁迫,并在一定浓度范围内直接或间接地影响以其为食的动物的生存,以至危害生命。  相似文献   

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