Taking refuge finally one risk follows gm crops wherever they ' re planted evolution . over time insect pests and weeds can become resistant to killing by routine chemical sprays 为了延缓昆虫对bt毒素产生抗药性，环保署规定，种植bt作物的人必须挪出部分农地种植传统作物。
Worries about the flow of genes from the original plant to others also surround gm crops . unwitting insects or the right wind might carry gm crop pollen to weedy plant relatives fertilizing them 不知情的昆虫，或者来得不是时候的一阵风，都可能将基改作物的花粉带到它们的野草亲戚身上，使之受精。
Almost every crop has weedy relatives somewhere in the world says stephen duke a usda plant physiologist in oxford miss . how do you keep gm crops out of places where they ' re not supposed to be “几乎每种农作物，在地球的某个角落都有野草亲戚。 ”植物生理学者杜克说， “你要怎么防止基改作物出现在不该出现的地方？ ”
In an epa meeting on gm crops last fall vaituzis acknowledged the lack of long - term data on bt crops and insect populations . such studies require more time than has been available since the registration of bt crops vaituzis remarked 2000年秋天，在环保署的一个基因改造作物会议中，卫图吉斯承认他们缺乏bt作物和昆虫族群的长期研究资料。
Either plant would readily accept the pollen from a gm relative . indeed scientists say gm crops in many countries could end up growing near their ancestral plants and sharing more than the sunshine overhead 事实上科学家认为，在许多国家，基改作物最后都可能栽种在它们的原始物种附近，它们共享的，可不只是头顶上的阳光，还有祖传的基因呢。
If that happened in the field she says wild oats might run amok in the western u . s . outcompeting native grasses with kudzu - like intensity . every gm crop power cautions brings its own environmental personality and its own risks 她说，这种情形如果发生在野外，获得抗病毒基因的野生燕麦便可能以燎原之势席卷美国西部，将其他原生草类逼得走投无路。
Gm food has been developing at an unprecedented rate . in the recent seven years , its " planting area grows thirty - five times . more than half of world ' s population lived in countries where gm crops are approved and grown today 转基因作物的发展速度是惊人的，近七年间种植面积增长了35倍，目前占世界人口一半以上的国家都在种植转基因作物。
Agriculture is an evolutionary arms race between plant protections and pests comments botanist jonathan wendel of iowa state university . and gm crops are just one more way that we ' re trying to outsmart pests 但是，有些环保人士怀疑情况是否真的这么乐观，他们认为，那些非bt作物收容所不是种植面积太小，就是设计太差，要期望昆虫长期不产生抵抗力，实在很难。
Recently , two new countries , india and the philippines , joined the global group of countries that are growing genetically engineered crops . countries growing gm crops in 2003 50 , 000 hectares , or more less than 50 , 000 hectares 方面，美国的种植面积为4 , 280万公顷，阿根廷为1 , 390万公顷，加拿大为440万公顷，巴西为300万公顷，中国为280万公顷，南非为40万公顷。
In the u . s . at least landscape logistics make it rather unlikely that herbicide - tolerant or bt crops will spread their biotech genes to weeds . that ' s because the gm crops sown in this country have no close relatives in the regions where they grow 在美国，至少还有生物地理的屏障， bt作物不太可能将植入的基因传播给野草，因为美国的基改作物多半种在没有近亲的地区。
