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991.
House flies were collected from dairies across New York state and the levels of resistance to seven insecticides were measured using standard laboratory assays with three to five diagnostic concentrations. The highest levels of resistance were found for tetrachlorvinphos, permethrin and cyfluthrin. Although levels of resistance to methomyl were somewhat lower, they were among the highest ever reported for field‐collected house flies. Resistance to pyrethrins was limited primarily to the lowest diagnostic concentration. House flies were susceptible to fipronil at all dairies, suggesting that this material would be highly effective for fly control. The levels of resistance were similar at all the dairies, irrespective of their insecticide use, suggesting substantial movement of flies between facilities. Relative to resistance levels found at New York dairies in 1987, resistance levels had increased for permethrin, were unchanged for tetrachlorvinphos and had decreased for dimethoate. To identify a single diagnostic concentration that could be used in the laboratory assays to assess accurately resistance levels in future studies, we carried out a ‘simulated’ field bioassay using formulated materials. A diagnostic concentration for each insecticide is proposed on the basis of a comparison of our bioassays. © 2001 Society of Chemical Industry 相似文献
992.
小麦条锈病重要抗源京核8811品系抗性遗传机制 总被引:12,自引:5,他引:12
采用常温(昼18℃/夜10℃),高温(昼24℃/夜15℃)两种温度处理,系统分析京核8811抗条锈性遗传基础及抗性特点。结果表明,京核8811中至少含有1对不完全显性主效抗性基因和2对隐性微效抗性基因。主效基因对温度不敏感,显性纯合时控制0-0;杂合体控制0;^ -2^ 。微效基因高温诱导,为性纯合、杂合或隐性纯合均对主效基因的抗性表达有修饰作用,当与杂合状态的主效基因重组,抗性达到高抗或免疫水平,自身隐性纯合可提供0;^ -2^ 的抗性。通过主效、微效基因的重组控制较强抗性和较宽抗性谱,反映出不同类型抗性谱互补的抗性基因重组产生的“基因的集团效应”。并就“基因的集团效应”的抗性特点及其在实现品种抗性持久化中的作用进行了探讨。 相似文献
993.
994.
北京地区家蝇乙酰胆碱酯酶不敏感基因表现型的检测 总被引:1,自引:0,他引:1
在1998~1999年对北京地区室外家蝇种群乙酰胆碱酯酶 (ACh E)的不敏感基因表现型进行了检测。以敏感品系为标准 ,海淀区 (A)、海淀区 (B)、丰台区、朝阳区家蝇种群具有的对敌敌畏不敏感基因表现型频率分别为 11%、34%、56%和24% ;对灭多威不敏感基因表现型频率为4%、4%、8%和20 %。ACh E对敌敌畏和灭多威的不敏感基因表现型 ,北京地区家蝇可分成4种 :1)对敌敌畏和灭多威均敏感型 ;2 )对敌敌畏不敏感 ,对灭多威敏感型 ;3)对敌敌畏敏感 ,对灭多威不敏感型 ;4 )对敌敌畏和灭多威均不敏感型。目前 ,在北京地区以对敌敌畏和灭多威均敏感的 ACh E表现型为主 ,其次为第二种类型 ,第三和第四种类型的频率不高。 相似文献
995.
叶枯唑防治水稻白叶枯病的作用方式研究 总被引:4,自引:0,他引:4
叶枯唑具有诱导受体植物水稻产生抗病性的作用 ,能使水稻体内脂质过氧化程度加强 ,刺激水稻体内产生 O-2 ,阻止白叶枯病菌侵入。O-2 清除剂 (甘露醇、抗坏血酸 )处理水稻能显著降低叶枯唑的保护作用。叶枯唑也能直接作用于水稻白叶枯病菌 ,抑制菌体生长 ,表现出治疗作用。 相似文献
996.
从配合力分析探讨甘蔗家系抗黑穗病的育种潜力 总被引:2,自引:0,他引:2
采用5×4不完全双列杂交设计选配的第1次无性种茎为试验材料,在人工浸渍接种黑穗病菌条件下,估算了9个亲本及其组合在新植蔗和宿根蔗的配合力效应。结果表明:①20个家系抗性差异较大,以CP67/412、ROCl为母本的半同胞家系表现较强抗病性,而以CP72/1210、CP65/357为母本的半同胞家系表现一定感病性;②甘蔗抗黑穗病遗传是由加性效应基因和非加性效应基因共同控制;③发现CP67/412、ROClgca效应值较高,CP57/614次之,均具有可作为抗源亲本的育种潜力,④根据配合力总效应值评价组合,认为CP67/412×崖84/153、ROCl×崖71/374、CP67/412×崖71/374、ROCl×崖84/153、CP67/412×崖73/512、CP57/614×崖84/153是抗黑穗病较强的组合,可用于今后抗黑穗病育种计划。 相似文献
997.
大麦云纹斑病菌对杀菌剂的抗性检测及同工酶谱类型 总被引:2,自引:0,他引:2
1993~1994年大麦云纹斑病菌(Rhynchosporium secalis)对杀菌剂多菌灵、三唑醇的抗药性监测表明,该菌对两种杀菌剂的敏感程度发生了变化,并且首次在田间发现了大麦云纹斑病菌的多抗菌株。这类菌株对多菌灵、乙霉威及三唑醇都具有抗药性,且抗性程度很高。与1990~1991年得到的资料相比,随着杀菌剂选择压力的增加,大田群体中三唑醇高抗菌株比例逐年增加。对该菌同工酶分析结果表明,α—酯酶有7种表现型,磷酸葡萄糖变位酶有2种表现型,过氧化氢酶有3种表现型,无论对去甲基抑制剂类(DMI)表现抗性或敏感菌株,无论调节酶还是非调节酶,其酶谱表现型的变异基本相似。这表明大麦云纹斑病菌对DMI类抗药性突变存在于多个菌系的基因型背景群体中,而不是只起源于单一的广泛分布的菌系。 相似文献
998.
999.
1000.
Simon R. Leather 《Integrated Pest Management Reviews》1996,1(3):163-180
The ecological implications of insect resistance in conifers are rarely discussed. It is however a fairly straightforward plant-insect interaction and should be treated as such, making use of the increasing amount of information in this field. Work on tree breeding is usually carried out by silviculturalists who, not surprisingly, rarely consider the insect component of the environment in which the treess are growing. In all fairness, it must be stated that many entomologists, fail to consider the plant component of the interaction. Clonal forestry will almost certainly result in the loss of genetic variability. The use of clonal material has already been cited as a possible source for the diminution of the resistance against pests and diseases and if particular resistance mechanisms against forest pests are sought in the future the reduction in genetic material caused by clonal selection could have serious consequences. The ethics of clonal forestry have been questioned as have the ethics of biotechnological advances in the area of recombinant DNA molecules. The potential of both these techniques should be publicized and brought to the attention of the general public and the scientific community at large and evaluated. To improve our forest environment and to protect the environment as a whole, entomologists, geneticists, physiologists and silviculturalists must work together to produce better trees that require little, if any, chemical aid, be it insecticides, herbicides, fungicides or fertilizers. An increasing awareness of the environmental problems generated by large-scale insecticide applications to forest plantations, coupled with an increasingly chemophobic work-force and the difficulty in obtaining pesticide registration for use in forest environments, means that the forest industry world-wide must look to the use of integrated control measures with more diligence than has been shown in the past. Many recent outbreaks of pests and diseases have been linked with particular seed origins of tree crops. Host plant resistance as part of a suite of other proposed integrated control tools is thus an obvious candidate for development. Despite this, scientists concerned with tree improvement continue to select largely for silvicultural traits rather than for resistance to pests and disease. The different avenues open to plant breeders are examined and the potential of breeding trees resistant to insect attack highlighted. Using resistant trees as part of an integrated pest management system has five very important properties. Firstly, there is no additional pest control cost to the grower, secondly, it operates at all levels of insect incidence and not just when the pest is at high population levels, thirdly, it reduces the insect population cumulatively, fourthly it avoids toxic residues and environmental pollution and, finally, it usually interacts well with the other integrated pest management strategies in existence. 相似文献