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新疆南部棉区转Bt基因棉花Bt杀虫蛋白表达规律研究 总被引：1，自引：0，他引：1
为研究新疆南部植棉区转Bt基因棉花Bt杀虫蛋白时空表达规律,本文利用ELISA技术于2009年和2010年对南疆种植的转Bt基因棉花‘中棉所41’、‘中棉所43’、‘236’、‘K9030’、‘T3’、‘中棉所44’、‘中棉所45’、‘K7’和‘SGK321’各生育期中不同器官中的Bt杀虫蛋白含量进行测定。结果发现：在时间表达上,大多数转Bt基因棉花叶片的Bt杀虫蛋白含量随着棉花发育进程而逐渐下降,在子叶期含量最高,至蕾期或吐絮期达到最低点。并且不同品种间Bt杀虫蛋白含量差异显著。在空间表达上,在花铃期,棉铃和花苞叶的Bt杀虫蛋白含量最低,大多数品种表现为叶片＞棉蕾＞花瓣（花柱）＞棉铃和花苞叶。 相似文献
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从山东省采集的750份土样中分离出苏云金芽孢杆菌菌株57株,这些菌株的晶体形态主要有菱形、圆形等。以夜蛾科害虫粘虫和甜菜夜蛾初孵幼虫为试虫,通过生测筛选出一株高毒力菌株QCL-1。菌株QCL-1对甜菜夜蛾的毒力显著高于标准菌株HD-1,对粘虫的毒力与HD-1相当。 相似文献
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Bt Transgenic Crops: Risks and Benefits 总被引：6，自引：0，他引：6
Raymond J.C. Cannon 《Integrated Pest Management Reviews》2000,5(3):151-173
Bt crops, predominantly maize and cotton hybrids, transgenically expressing cry genes derived from Bacillus thuringiensis, were planted on approximately 14 million hectares (worldwide) in 1999. Preliminary reports suggest that in most cases pesticide use was reduced, and in some situations there were significant increases in yields and profits. However, assemblages of secondary pests – such as aphids, plant bugs and thrips – also exist in Bt crops, and although the overall need for scouting and chemical control is reduced in Bt crops, there may be a requirement for additional, conventionally applied chemicals to control such non-target pests.Naturally-occurring Bt toxins with activity against a wide variety of pest species have been discovered and are thus potentially available for engineering into Bt crops to control a broader spectrum of pests than are currently targeted. New Bt crops and second-generation products incorporating an expanding range of Cry toxins and other arthropod targeted genes are in development and could become available for introduction to the market within the next few years.Insecticide resistance management (IRM) strategies for Bt crops are reviewed in the context of studies on selection pressures and the potential for resistance development in target populations. The so-called, high dose strategy, combined with the use of refuges, is widely agreed to be the best technical approach for managing resistance, and evidence is accumulating that separate refuges are more effective at conserving pest susceptibility than mixed refuges. A widespread consensus on the necessity for such measures, and an appreciation of the importance of multi-tactical approaches, has developed. Monitoring programmes, protocols and studies relevant to detecting the early development of resistance to Bt Cry toxins are described.Field monitoring of non-target entomofauna has not revealed significant differences in the abundance or biodiversity of beneficial insects associated with Bt maize. Indeed, laboratory studies of effects on parasitoids suggest that Bt plants may even have an environmental advantage over broad spectrum pesticides. However, more complex, multi-trophic, long-term experiments are needed to thoroughly assess the compatibility of Bt crops with non-target invertebrates and to define the complex relationship between IRM, target species and their natural enemy assemblages. Studies on the effects of transgenically-expressed Cry toxins on non-target insects, and their persistence in soil and on leaves, is reviewed. It is suggested that there is currently no generally agreed framework, or methodology, within which ad hoc experimental results can be accommodated, and each crop-transgene combination has to be assessed on a case-by-case basis. Studies proposing a conceptual approach to evaluating risks associated with Bt crops are highlighted and potential benefits and hazards are reviewed. 相似文献
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棉铃虫体内的钙黏蛋白（CAD）和氨肽酶N1（APN1）是Bt的主要作用靶标,两种受体蛋白的变化也是棉铃虫对Bt产生抗性的主要原因。本文利用实时荧光定量PCR技术比较了Bt抗性和敏感棉铃虫CAD和APN1的表达量变化,分析受体蛋白表达量变化与抗性的关系。结果表明,与敏感品系相比,抗性品系棉铃虫CAD和APN1的表达量明显降低,1、2龄幼虫的差异达到极显著。在敏感品系中,CAD和APN1的表达量随龄期的增加呈现“V”字形变化,1、2龄幼虫的表达量最高,3、4龄时显著降低,到5龄时表达量又有所增加。抗性品系中CAD和APN1的表达量提前降低,与表达量最高的1龄幼虫相比,2、3龄时表达量显著降低,到4、5龄时又略有回升。说明棉铃虫中肠钙黏蛋白、APN1表达量的下降与抗性相关,且不同龄期棉铃虫幼虫表达量不同。 相似文献
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随着BtCry作物在我国的广泛应用和推广,靶标害虫对其抗性风险已成为BtCry作物生态安全研究的重要内容。氨肽酶N(Aminopeptidase N,APN)是位于昆虫中肠刷状缘膜囊泡(Brush Border Membrane Vesicles,BBMV)上BtCry毒素重要的受体蛋白之一,它与BtCry毒素的结合能力决定了BtCry毒素的杀虫活性及昆虫对Bt抗性的产生。本文从APN的结构特征与分类、APN与BtCry毒素的结合特异性、结合位点、结合过程中的分子互作机制及APN变异导致昆虫抗性产生几方面系统综述了鳞翅目昆虫中肠BtCry受体蛋白-氨肽酶N与BtCry毒素的结合及其与Bt抗性关系的研究进展。 相似文献
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组建了Bt和乙酰甲胺磷两类不同性质、不同LT50 剂量母液配对的类群A和B(以下简称A群和B群),其配对母液LT50的大小,前者均为"乙酰甲胺磷＜Bt",后者均为"乙酰甲胺磷＞Bt"。以小菜蛾Plutella xylostella Linnaeus为试虫对两类群的系列体积混配组合逐一进行室内毒力测定,按同一死亡率观察时段范围,计算每一LT-p线所涉及的梯形面积,并将该面积定义为药效,亦即药剂致死作用的时间动力强度;以该面积的大小作为量化指标,再引申出计算动力增强系数Ⅰ和Ⅱ,运用于试验结果的药效分析。同时与其他不同药效量化评价方法进行了比较。结果表明:①在配对性质不同的类群A和B中,不同配对系列混配组合筛选出的"优良配比"数目不同。如A群有关配对的9个混配组合中,属于"优良配比"的一般仅在2个以下,而在B群内一般可达4~7个,表明B群的配对优于A群。② 配对的优越性与母液间LT50值的合理搭配有关。如配对 67.3/792.5 和43.6/473.1,其LT50的差异明显较大,致使动力增强系数Ⅱ较小,仅为73.5和 90.4;而LT50差异明显较小、或较适宜的配对80.57/90.36和23.76/45.31,其动力增强系数Ⅱ则较大,分别达110.3和101.8。 相似文献
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利用室内饲喂法,以泗棉3号为对照,研究转双价(Bt CpTI)基因棉SGK321和转单价(Bt)基因杂交棉科棉3号对甜菜夜蛾室内种群生长发育和趋性的影响。结果表明:SGK321、科棉3号饲喂的甜菜夜蛾幼虫死亡率、成蛹下降率和幼虫成蛾下降率显著高于对照,且SGK321饲喂的化蛹下降率显著高于科棉3号。SGK321、科棉3号饲喂的甜菜夜蛾幼虫期显著长于泗棉3号,其蛹重显著轻于泗棉3号;SGK321饲喂的幼虫期长于科棉3号,其蛹期和蛹重接近于科棉3号;三种棉花饲喂的甜菜夜蛾的产卵前期、产卵期、产卵量均表现为SGK321<科棉3号<泗棉3号,其中SGK321饲喂的产卵期显著短于泗棉3号;SGK321、科棉3号饲喂的雌成虫寿命相近,但明显短于泗棉3号。三种棉花饲喂的甜菜夜蛾净增长率(R0)、内禀增长率(rm)、周限增长率(λ)和种群增长指数(I)均表现为SGK321<科棉3号<泗棉3号;世代平均周期(T)和种群加倍时间(DT)均表现为SGK321>科棉3号>泗棉3号。甜菜夜蛾2～5龄幼虫对棉花的趋性强弱顺序为泗棉3号>科棉3号>SGK321。 相似文献
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转Bt基因杨树对杨扇舟蛾的抗性 总被引：1，自引：0，他引：1
通过室内饲养和组织切片,研究了表达Cry1A杀虫蛋白的中嘉8号杨树转Bt基因植株对杨扇舟蛾的抗虫效果。结果表明：随着饲养时间的延长,幼虫死亡率和体重抑制率呈上升趋势,处理2d仅分别为10%和6.85%,处理4d分别增加到48.33%和27.93%,处理10d分别达81.67%和63.03%。此外,处理12d取食非转基因杨树幼虫化蛹率100%,而取食转Bt基因杨树幼虫的化蛹率仅为18.18%。组织切片观察表明,取食转Bt基因杨树叶片幼虫的中肠上皮细胞排列松驰,与肠壁基底膜分离,细胞界限较模糊,部分上皮细胞形成空泡。因此,初步认为转Bt基因杨树对杨扇舟蛾幼虫的抗性表现为毒杀作用和抑制其生长发育。 相似文献
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粘虫Mythimna separata(Walker)是我国玉米上的重要害虫。转Bt基因玉米为防治粘虫提供了新的途径。从室内生测和田间抗性鉴定分别研究了转cry1Ab基因抗虫玉米YieldGard对粘虫的杀虫效果。用4~7叶期转cry1Ab基因玉米心叶室内饲养1~3龄粘虫幼虫3、7和10天的死亡率分别为39.0%~92.0%、96.0%~98.0%和97.0%~100%,第14天全部死亡,而对照的死亡率分别为3.0%~8.0%、6.0%~20.0%和11.0%~28.0%,差异极显著。取食转cry1Ab基因玉米的幼虫不能正常生长发育,存活10天的幼虫其体重仅为取食对照玉米的9.0%。田间玉米4~5叶期,分别接1~6龄粘虫幼虫于转cry1Ab基因和非转基因玉米心叶。转cry1Ab基因玉米上各龄期幼虫平均存活率仅为0.0~6.7%,极显著低于非转基因玉米的8.3%~80.0%。转cry1Ab基因玉米的危害级别0.1~0.7,显著小于非转基因玉米的2.1~7.3。结果说明转cry1Ab基因玉米YieldGard对粘虫各龄幼虫有很高的杀虫作用和田间控制效果,同时能有效保护玉米免受危害。 相似文献
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转基因抗虫棉的抗虫局限性及虫害综合防治措施 总被引：1，自引：0，他引：1
近几年来,经过农业部门的努力,转基因抗虫棉已在广水地区大面积推广,但农民对抗虫棉的认识依然存在两种误区:一种认为既然是抗虫棉,那就是百虫不侵,不必防虫,只需防病;另一种认为抗虫棉根本就不抗虫,因此在病虫防治上同普通棉花一样对待。针对这两种错误认识,笔者通过1999～2001年连续3a对比观察研究,总结出了抗虫棉抗虫局限性及综合防虫措施,以便充分发挥抗虫棉的优势,保护生态 相似文献