Potential for the environmental impact of transgenic crops

In recent years, there has been increasing interest in how changes in agricultural practice associated with the introduction of particular genetically modified (GM) crops might indirectly impact the environment. There is also interest in any effects that might be associated with recombinant and novel combinations of DNA passing into the environment, and the possibility that they may be taken up by microorganisms or other live biological material. From the current state of knowledge, the impact of free DNA of transgenic origin is likely to be negligible compared with the large amount of total free DNA. We can find no compelling scientific arguments to demonstrate that GM crops are innately different from non-GM crops. The kinds of potential impacts of GM crops fall into classes familiar from the cultivation of non-GM crops (e.g., invasiveness, weediness, toxicity, or biodiversity). It is likely, however, that the novelty of some of the products of GM crop improvement will present new challenges and perhaps opportunities to manage particular crops in creative ways.     

Calling the tunes on transgenic crops: the case for regulatory harmony

Genetically modified (GM) crops are now grown commercially in 23 countries, with another 29 granting approval for import and release into the environment. Despite the socio-economic and environmental benefits of the technology, further development is being hampered by differences in national regulatory frameworks relating to research, biosafety, and to the trade and use of GM crops. The biosafety regulations in different countries are based on five main international instruments that influence the development of national biosafety systems in terms of field trial permit requirements, risk assessment criteria, labeling, traceability, transparency, public awareness, post-monitoring and import regulations. The global harmonization of data collection, testing procedures and information exchange would help to remove artificial trade barriers, expedite the adoption of GM crops, foster technology transfer and protect developing countries from exploitation, instilling confidence and bringing the benefits of GM products to the consumer.     

Economic impact of transgenic crops in developing countries

Transgenic crops are being adopted rapidly at the global level, but only a few developing countries are growing them in significant quantities. Why are these crops so successful in some countries but not in others? Farm level profitability ultimately determines whether farmers adopt and retain a new technology, but this depends on much more than technical performance. Recent economic studies in developing countries find positive, but highly variable, economic returns to adopting transgenic crops. These studies confirm that institutional factors such as national agricultural research capacity, environmental and food safety regulations, intellectual property rights and agricultural input markets matter at least as much as the technology itself in determining the level and distribution of economic benefits.     

转基因作物对天敌的影响研究进展

随着转基因作物商业化种植的发展,人们越来越关注转基因作物对生态安全的影响,其中的一个焦点就是转基因作物对非靶标昆虫天敌的影响。转基因作物主要通过花粉和取食转基因植物的昆虫两个途径影响天敌的种群。目前国内外转基因作物对天敌影响的研究方法包括田间种群调查,室内转基因作物花粉或取食转基因作物的害虫对天敌影响研究,近年来把高浓度毒蛋白通过人工饲料喂养给天敌的Tier-1法研究也逐渐增多。大多数研究表明,转基因抗虫作物中的杀虫蛋白通过花粉和取食转基因植物的昆虫两个途径对天敌没有产生不利的影响。同样,Tier-1法研究结果,也证明浓度毒蛋白喂养对天敌并没有产生不利的影响。     

Genetic diversity in major farm crops on the farm and in reserve

Genetic vulnerability does not at this time present a major threat to production of United States field crops, according to a 1981 survey of U.S. crop breeding directors. But plant breeders do regard genetic vulnerability as an important and potentially dangerous problem. The 1981 survey indicated that although the genetic base of U.S. field crop production is not as narrow as in 1970, it still is concentrated on a relatively small number of favored cultivars. Genetic diversity is provided, nevertheless, in other and less obvious ways. Survey responses indicated that the genetic base of the elite germplasm pool is wider and provides more useful diversity than is usually supposed. However, breeders also value the national germplasm repositories as indispensable sources of needed diversity.     

转基因作物对生物多样性的影响

转基因作物对生物多样性的影响是重要的环境问题之一,近年来,已有这类实验的报道。夏敬源等的研究说明大田种植转基因Bt虫棉花对棉铃虫优势寄生性天敌齿唇姬蜂（Campoletis chlorideae）和侧沟绿茧蜂（Microplitis sp.）的寄生率、羽化率和蜂茧质量造成严惩的危害。国际上一些昆虫学家也做了很好的工作,尤其1999年5月Losey在Nature上发表转基因Bt抗虫玉米在实验室水平上引起大斑蝶死亡报道后,世界范围内引起极大的反响,在有关经遗传修饰生物体（GMOs）的潜在生态风险和人体健康影响的问题上美国始络抱抵制的强硬态度,这次也开始有所所松动。两个有影响的美国玉米加工公司富布不再接受欧盟拒绝进口的转基因玉米品种。欧盟宣布在进一步研究得到结论前冻结转基因作物产品进口的审批。欧盟所属有关国家有的禁止进口,有的反对欧盟审批。科技界及公众众说纷纭。建议我国政府要加强GMOs潜在生态风险及对公众健康的研究及商业化生产后的监测。     

The role of transgenic crops in sustainable development

The concept of sustainable development forms the basis for a wide variety of international and national policy making. World population continues to expand at about 80 M people per year, while the demand for natural resources continues to escalate. Important policies, treaties and goals underpin the notion of sustainable development. In this paper, we discuss and evaluate a range of scientific literature pertaining to the use of transgenic crops in meeting sustainable development goals. It is concluded that a considerable body of evidence has accrued since the first commercial growing of transgenic crops, which suggests that they can contribute in all three traditional pillars of sustainability, i.e. economically, environmentally and socially. Management of herbicide-tolerant and insect-resistant transgenic crops to minimize the risk of weeds and pests developing resistance is discussed, together with the associated concern about the risk of loss of biodiversity. As the world population continues to rise, the evidence reviewed here suggests it would be unwise to ignore transgenic crops as one of the tools that can help meet aspirations for increasingly sustainable global development.     

转基因作物对土壤生态系统的影响

综述了转基因作物对土壤生态系统影响的研究进展,包括转基因作物中的外源基因在土壤中的活性,转基因作物对土壤微生物区系有土壤酶活性的影响以及转基因作物对土壤动物区系的影响,转基因作物对土壤生态系统的影响与导入的外源基因特性和土壤类型相关,转基因产物进入土壤后引起的土壤生物变化的程度依赖于许多因素,最重要的决定因素是生态系统的复杂性和稳定性,评价不同转基因作物对土壤生态系统的影响具有重要的生态学意义,急需发展和完善以分子生物学为主的风险评价方法。     

转基因抗虫作物对非靶标昆虫的影响

转基因抗虫作物自 1996年被批准商业化种植以来 ,它的抗虫性和经济效益已得到了普遍肯定 ,同时 ,转基因抗虫作物对非靶标生物的影响 ,如转基因抗虫作物的长期种植 ,是否会导致次要害虫上升为主要害虫 ,是否会影响有益昆虫 ,包括重要经济昆虫、捕食性和寄生性天敌以及重要蝶类的种类及种群数量 ,已成为转基因抗虫作物生态风险评估的重要内容。一些研究结果表明 ,转基因抗虫作物在对靶标害虫有效控制的同时 ,一些对杀虫蛋白不敏感的非靶标害虫有加重危害的趋势 ,由于种植转基因抗虫作物 ,减少了化学农药的使用 ,客观上也使非靶标害虫种群数量上升 ,这对转基因抗虫作物害虫综合治理提出了新的要求。靶标害虫数量的减少直接影响了害虫天敌种群数量 ,靶标害虫取食转基因抗虫作物后发育迟缓 ,也间接影响了天敌昆虫的生长发育 ,转基因抗虫作物的花粉或花蜜是一些重要经济昆虫如蜜蜂、熊蜂和一些寄生蜂 ,甚至捕食性天敌的食物来源 ,或花粉飘落到一些鳞翅目昆虫如家蚕或重要蝶类昆虫的寄主植物上 ,直接或间接对这些昆虫造成一定影响。目前大多数研究表明转基因抗虫作物对非靶标昆虫 ,特别是对有益昆虫没有明显的不利影响 ,也有研究报道认为对某些有益昆虫有一定的不良影响。这为深入开展转基因抗虫作物的生态安全     

转Bt基因作物对土壤节肢动物的生态风险性

土壤节肢动物在土壤生态系统物质循环中起着非常重要的作用,因此人们越来越关心转基因作物对土壤节肢动物的生态安全性。本文在介绍转基因作物对土壤节肢动物影响机制的基础上,重点论述了土壤跳虫、螨类、甲虫、水生昆虫等节肢动物对不同转基因作物响应的研究进展,旨在为科学全面的开展转基因作物土壤生态风险评价提供参考。     

RNAi转基因作物安全评价研究进展

在秀丽隐杆线虫中首次发现双链RNA(dsRNA)能特异性地导致基因沉默(RNAi)现象后,人们开始大量地研究RNAi技术,并将其应用于功能基因的研究,来提高作物的抗性和改良遗传育种等。本文详细介绍了RNAi的技术原理,并且对RNAi技术与传统转基因技术的区别进行分析,阐述了该技术具有重要的生物学意义,以及在农作物害虫防治领域的占据独特优势。基于RNAi技术存在的潜在脱靶效应,从改良植物、靶标生物和生态环境的3个方面具体分析该技术可能存在的风险,为RNAi技术的风险评估提供参考。由于RNAi技术仍存在风险,为了维护生态多样性和保障人们的人身安全,应尽快建立起符合实际需求的安全性评价方法,本文针对RNAi转基因作物的环境安全和食用安全2个方面的评估方案进行概述。RNAi技术对减少害虫数量、提高水稻产量、降低种植成本以及减少化学农药污染、促进农业可持续发展来说具有重要意义,但该技术仍存在风险,需要进一步监管和研究,建立完善的生态评价系统,让RNAi技术在农业生产上发挥作用。     

转基因作物和转基因技术的发展与未来

转基因作物的安全性问题在20世纪末引起全球性的争论,一些人反对转基因植物和转基因技术.本文概述了转基因植物产生的必然性、应用现状、发展趋势、引起争论的主要原因以及必须建立的安全性保障,阐明对转基因作物和技术应采取的科学态度.     

转Bt基因作物对非靶标土壤动物的影响

转Bt基因作物已经在世界范围内广泛种植.随着转基因作物的快速发展与推广,有必要深入研究其对土壤生态系统的影响.本文概述了转Bt作物对土壤动物群落以及蚯蚓、线虫、虫兆虫、螨类和甲虫等重要类群的种群动态影响的研究进展,介绍了转Bt基因作物的发展历史,分析了Bt蛋白进入土壤的途径及其在土壤环境中的残留与降解的动态,阐述了未来转Bt基因作物对非靶标土壤动物影响的生态风险分析的重要领域,旨在为研究转Bt基因作物对非靶标土壤动物影响提供参考.     

The income and production effects of biotech crops globally 1996-2010

A critical feature in evaluating the global value of crop biotechnology in agriculture must include an assessment of its economic impact at the farm level. This paper follows earlier studies which examined economic impacts on yields, key costs of production, direct farm income, indirect (non-pecuniary) farm level income effects and impacts on the production base of the four main crops of soybeans, corn, cotton and canola. The commercialization of biotech crops is continuing to proceed rapidly, with significant changes in the overall level of adoption and impact taking place in 2010. This updated analysis shows that there have been substantial net economic benefits at the farm level amounting to $14 billion in 2010 and $78.4 billion for the 15-year period (in nominal terms). The non-pecuniary benefits associated with the use of the technology have also had a positive impact on adoption (in the US accounting for the equivalent of 22% of the total US direct farm income benefit). Biotech crops are, moreover, making important contributions to increasing global production levels of the four main crops. They have, for example, now added 97.5 million tons and 159 million tons respectively, to the global production of soybeans and corn since the introduction of the technology in the mid-1990s.