转基因抗虫植物对天敌昆虫的影响

迄今对16种捕食性和7种寄生性天敌昆虫个体进行的毒性测定表明，转基因植物对天敌昆虫没有直接毒性；取食了转基因植物的猎物对大部分捕食性天敌昆虫个体无毒副作用。取食了转基因植物的寄主害虫如表现亚致死反应，则对寄生蜂个体无毒副作用，甚至对寄生蜂与抗虫作物间有增效作用；如寄主表现致死反应，则对寄生蜂个体有明显毒副作用。转Bt基因棉花，玉米和马铃薯田中主要广谱捕食性天敌种群数量等于或显著高于常规田，生测中对普通草蛉的副作用并未使其大田种群受到不良的影响；寄生性天敌昆虫种群数量除在个别Bt棉田中明显减少外，在其他Bt作物田中均等于或高于常见田，除个别棉田外，未发现Bt作物田中天敌群落受到不良影响，部分研究发现Bt作物田中某些非靶标刺吸口器害虫上升为主要害虫，数量明显高于常规田，建议采用“三层次检测体系”评价转基因作物对天敌昆虫的影响。     

转基因植物对农业的影响

介绍了转基因植物对农业的影响,如抗虫、抗病、抗逆、固氮、高产、优质及对环境安全性和食品安全性。     

抗同翅目昆虫的相关基因及其转基因抗虫植物研究进展

植物抗虫基因工程为控制害虫的危害提供了新的途径。目前,对同翅目害虫具抗虫活性的基因有三种来源,(1)植物:如植物凝集素基因、番茄抗线虫基因Mi等;(2)微生物:如异戊烯转移酶抗性基因;(3)动物:如来自一些昆虫的蛋白酶抑制素基因。其中一些基因已被成功地转入植物体内,并且获得的转基因抗虫植物对同翅目害虫的生长、发育、繁殖能力等方面都具有一定的抑制作用,表现出这些抗虫基因在防治这类害虫中的应用潜力。雪花莲凝集素可通过人工饲料或转基因作物进入昆虫体内,并通过营养级传递于天敌,进而对天敌造成直接或间接的影响。     

真菌源蛋白类激发子及其转基因植物研究进展

真菌源蛋白类激发子是广泛存在于植物病原真菌的信号传导分子,不仅在植物与病原菌互作中起重要作用,而且还具有广谱诱导植物抗性和促进植物生长的功能。本文就真菌源蛋白类激发子的种类、功能及蛋白激发子基因转化植物等研究进行了综述。     

转基因抗虫植物研究进展

虫害是制约农作物高产、稳产的重要因素。全球每年因施用化学杀虫剂防治农业害虫的费用高达10 0亿美元 ,即使如此 ,每年虫害损失仍占农作物总产量的 14% ,价值达数千亿美元。在我国 ,因虫害水稻减产在 10 %以上 ,小麦减产近 2 0 % ,棉花减产在30 %以上 ;每年造成的损失达 60～ 10 0亿元。化学杀虫剂能造成不可再生资源的巨大浪费、低效率 (指到达靶标部位的比例 )、不可接受的环境后果 ,比如食物链污染、水资源污染、食物中的药物残留 ,从而导致农业生态系统的非持续发展。微生物杀虫剂在一定程度上克服了化学杀虫剂的缺点 ,但很难同时管理…     

转基因植物与病虫害防治

自80年代将Bt毒蛋白转入烟草和西红柿以来，转基因作物在法律、管理、专利以及它们的利与弊方面引起了不少风波。现将这些争论的要点简要地作一介绍，以供参考。互关于转基因作物登记法规与协调在80年代将B反毒蛋白转入西红柿后，有人认为“当西红柿是一种杀虫剂时，西红柿也就不是西红柿了”。这使美国的管理机构产生了法律上的困境。因为美国环保局（EPA）认为，这属于联邦政府的杀虫剂、杀菌剂和杀鼠剂法规范畴，故要求作为一种农药进行登记；如果EPA不要求登记，则食品和药物管理局（EPA）根据纯食品、药物和化妆品法规，因西红柿…     

转基因作物对土壤微生物多样性影响

土壤微生物的多样性及其活性是保持农业生态系统稳定的基础,而作物的改变对土壤微生物的多样性结构和活性具有显著的影响。转基因作物被引入到农田后所带来的微生物群落的变化及对农业生态系统所带来的不确定因素,已成为研究热点。本文综述了近年来转基因作物对土壤微生物群落影响的研究进展,并且着重介绍了转基因抗虫棉对根际微生物多样性影响的研究进展。     

转基因植物农药的毒理学评价

本文从现有农药分类入手,介绍了生物农药的一般概念,特别是植物农药（Plant-Incorporated-Protectants,PIPs）的概念及其安全性评价原则。并以B.t10转基因玉米为例,详细解析了PIPs农药毒理学安全性评价的靶标——蛋白及相关遗传物质如蛋白编码基因、标志基因、报告基因;一般资料要求,如毒性、致敏性、抗药性和非预期效应;评价原则和决策依据,为今后评价此类农药奠定基础。     

美国转基因植物农药登记情况

美国是世界上转基因植物农药登记管理起步较早的国家,独特的登记管理方式促进了转基因植物农药在美国的发展,目前40多个转基因植物农药在美国环保署取得登记。本文介绍了美国转基因植物农药产品的登记情况。     

数字PCR在转基因植物检测中的应用

随着转基因植物种植规模不断扩大,对其中转基因成分检测也提出了新的要求。近年来,数字PCR作为一种新兴的分子生物学技术在其检测方面得到了广泛应用。本文主要介绍了数字PCR的原理及数字PCR在转基因检测中的应用优势,并对转基因植物检测中的转基因成分定量检测、标准物质制备与定值及外源基因拷贝数鉴定等应用进行了总结。     

Risk assessment to honey bees: a scheme developed in France for non-sprayed systemic compounds

BACKGROUND: Directive 91/414/EEC envisages that the systemic properties of active substances, if any, are taken into account in evaluating the risk posed to the environment by plant protection products. Among others, honey bees may be exposed to substances via this route, which may pose problems when substances with high toxicity are ingested through pollen or nectar. The guidance documents in support of the risk assessment to bees within the framework of Directive 91/414/EEC do not provide detailed technical guidance on how to proceed in a risk assessment for substances with systemic properties. RESULTS: A stepwise approach aiming specifically to assess the risk posed by non-sprayed systemic substances to bees is therefore proposed. This approach first identifies substances with systemic properties, which should be quantified in plant material as pollen and nectar. Exposure estimates calculated for different categories of bees (e.g. foraging bees), based on expected concentrations of the product in pollen or nectar, may be compared with several toxicity endpoints for acute or chronic effects on adults and/or larvae with a toxicity/exposure ratio, which is a measurement of potential risks. CONCLUSION: Such a ratio is proposed to be used as a trigger for any further refined assessment that would focus on the measurement of effects at the colony level.     

Altered pesticide use on transgenic crops and the associated general impact from an environmental perspective

The large-scale commercial cultivation of transgenic crops has undergone a steady increase since their introduction 10 years ago. Most of these crops bear introduced traits that are of agronomic importance, such as herbicide or insect resistance. These traits are likely to impact upon the use of pesticides on these crops, as well as the pesticide market as a whole. Organizations like USDA-ERS and NCFAP monitor the changes in crop pest management associated with the adoption of transgenic crops. As part of an IUPAC project on this topic, recent data are reviewed regarding the alterations in pesticide use that have been observed in practice. Most results indicate a decrease in the amounts of active ingredients applied to transgenic crops compared with conventional crops. In addition, a generic environmental indicator -- the environmental impact quotient (EIQ) -- has been applied by these authors and others to estimate the environmental consequences of the altered pesticide use on transgenic crops. The results show that the predicted environmental impact decreases in transgenic crops. With the advent of new types of agronomic trait and crops that have been genetically modified, it is useful to take also their potential environmental impacts into account.     

应用双重数字PCR对转基因玉米成分进行定量方法研究

基于微滴式数字PCR平台,研究建立了一种在同一个微滴反应体系中同时测定样品中两种靶序列的双重微滴式数字PCR定量方法。结果表明,所建立的T25品系双重PCR方法能特异性检出转基因玉米T25,而其他转基因玉米、油菜、水稻等作物品系均没有扩增。灵敏度实验数据表明,所建立的T25双重数字PCR方法,在相对标准偏差≤25%时可以检测到4.6个T25特异性边界序列分子,在不考虑各重复间相对标准偏差的情况下可以检测到1个拷贝。定量结果准确性比较研究显示,与采用分别定量内源基因和T25边界序列来定量转基因成分结果相比较,所建立的T25双重数字PCR定量结果因消除了取样误差结果更准确,以上研究结果表明双重微滴式数字PCR定量方法比单重微滴式数字PCR定量方法更适用于进出境农产品转基因成分的定量检测。     

转基因延熟番茄"华番一号"的品系特异性检测方法

本文使用反向PCR方法克隆了转基因延熟番茄"华番一号"(Bioscein)的外源基因和番茄基因组之间的一段边界序列,并依据此段序列设计了具有品系特异性的引物和荧光探针,以实时荧光PCR技术建立了华番一号的品系鉴定检测方法,扩增片段长108bp,横跨在Nos启动子和番茄基因组之间.以转基因大豆(RR)、转基因玉米(Mon810)、转基因抗草甘膦油菜、转基因棉花(保龄棉)、非转基因番茄、马铃薯、茄子、大椒、大米、小麦、烟草等为试材,证明本方法同其它转基因作物及其它蔬菜无非特异性反应.本方法在检测华番一号番茄时,相对检测灵敏度可达到0.1%,绝对灵敏度达到20个拷贝.由于本方法的PCR扩增产物长度只有108bp,因此该方法也可以用于检测加工产品中的转基因成分,或作为常规PCR定性检测后的确证实验方法.     

A review of progress toward field application of transgenic mosquitocidal entomopathogenic fungi

In Africa, adult mosquito populations are primarily controlled with insecticide‐impregnated bed nets and residual insecticide sprays. This coupled with widespread applications of pesticides in agriculture has led to increasing insecticide resistance in mosquito populations. We have developed multiple alternative strategies for exploiting transgenic Metarhizium spp. directed at: (i) shortening the lifespan of adult mosquitoes; (ii) reducing transmission potential of Plasmodium spp.; (iii) reducing vector competence via pre‐lethal effects. The present challenge is to convert this promising strategy into a validated public health intervention by resolving outstanding issues related to the release of genetically modified organisms. © 2019 Society of Chemical Industry     

Toxicity of diafenthiuron to honey bees in laboratory,semi‐field and field conditions

BACKGROUND: Cardamom, an important spice crop often attacked by many insect pests, is controlled mainly using synthetic insecticides. As honey bees play a vital role in pollination in cardamom, the impact of insecticides on honey bees needs to be explored to assess its safety. RESULTS: Risk assessment based on contact toxicity revealed diafenthiuron to be a non‐selective insecticide to bees with a low selectivity ratio (the ratio between the LD₅₀ for beneficial and pest species). A dose of diafenthiuron that killed 90% of cardamom borer, Conogethes punctiferalis Guenee, was found to kill 100% of Indian bees. Based on the hazard ratio (the ratio between the field‐recommended dose and the LD₅₀ for the beneficial), diafenthiuron was found to be slightly to moderately toxic to bees. Diafenthiuron, even at low concentrations of LC₁ (the concentration that killed 1% of bees), was found to affect the foraging and homing behaviour of Indian bees. Of bees fed with 30 µg mL^?1 of diafenthiuron, 40% were found missing on the third day after exposure. However, diafenthiuron did not affect bee visits to the cardamom fields. CONCLUSION: Diafenthiuron is more highly toxic to Apis cerana indica F. than to C. punctiferalis by contact, using selectivity ratio and probit substitution methods of risk assessment, but the hazard ratio revealed diafenthiuron to be a slightly to moderately toxic chemical. Diafenthiuron was found to affect the foraging and homing behaviour of bees at sublethal concentrations. Thus, sublethal effects are more relevant in risk assessment than lethal and acute effects. Copyright © 2010 Society of Chemical Industry