Biotech Crops Biotech crops bring higher yields with solid environmental

游客2024-01-02  9

问题     Biotech Crops
    Biotech crops bring higher yields with solid environmental benefits: less use of energy, better soil conservation, less fertilizer employed and therefore less polluting runoff into groundwater. But the voices opposed are also loud. Prof. Bruce Chassy, an American expert in the field, was recently in Beijing for an international conference; our journalist took the opportunity to interview him on the subject.
    Q: The people who denounce biotechnological crops say they are worried about the possibility of the alien genes in genetically modified crops spreading to other species. For example, suppose herbicide-tolerant cotton transmits its genes to weeds—then the weeds could become "superweeds". Do you think this concern is justified?
    A: Before a new biotech crop can be grown in the USA, it must be approved by the US Department of Agriculture and the Environmental Protection Agency. They require developers to provide evidence that there will be no unexpected or damaging environmental consequences if the crop is planted. The questions require an examination of the potential for gene flow and any consequences that would ensue, including issues such as superweeds and the impact on a variety of non-target species such as birds, butterflies, earthworms and frogs. Resistance to the herbicides used in conventional agriculture does occur from time to time, and there is no reason to believe that biotech crops will produce any different kind of herbicide-resistant weeds than we already see in agriculture. In fact, after six years of planting herbicide-resistant crops in the US, we have not seen the emergence of herbicide-resistant weeds.
    Q: In the US what percentage of people support biotech crops? And do those who support biotech crops also eat biotech crops? What percentage of food on the market has genetically modified ingredients?
    A: US consumers have been subjected to a very effective anti-biotechnology propaganda campaign for the last few years, but according to polls over 70% support biotechnology. For example, in a recent referendum in Oregon, voters rejected a proposal to require special labels on all products containing biotech ingredients by an overwhelming 73% to 27%. That’s probably because consumers know that we have an effective regulatory system. Many may also know that 70% -80% of the processed food products on supermarket shelves contain one or more ingredients derived from biotech crops. All Americans eat biotech crops unless they deliberately seek out products that are labeled otherwise. Evidence suggests that this is less than 5% of consumers.

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答案     转基因农作物
    采用生物技术的转基因农作物不仅产量高,对环境也有很大益处,如能量消耗少、对土壤保护有利、化肥用得少,因而汇入地下水的污流也随之减少。但是反对生物技术的呼声也很高。最近,转基因领域的美国专家布鲁斯?沙西教授来到北京参加国际会议,本报记者就此问题采访了他。
    问:指责生物技术的人们说,他们担心转基因农作物中的外来基因会扩散到其他物种中。比如,倘若抗除草剂的棉花把“抗除草剂基因”传给了杂草,那就会出现超级杂草。您觉得这种担心有道理吗?
    答:在美国,一种新的采用转基因技术的农作物在种植前,必须经过美国农业部与环保局的批准。他们要求研制者提供证明,证明该农作物种植后不会对环境产生预料不到的或是有害的后果。这些问题要求对基因转移以及任何由此产生的后果的可能性,包括超级杂草、对于非目标性物种如鸟类、蝴蝶、蚯蚓、青蛙等各物种的影响进行检验。对传统农业使用的除草剂产生抵抗力在自然界时有发生,因此没有理由认为采用生物技术的农作物会产生出与我们在农业中已经见到的那些抗除草剂杂草所不同的杂草。实际上,美国种植了六年的抗除草剂作物,我们并没有看到抗除草剂杂草的出现。
    问:美国人当中有多大比例支持利用生物技术种植作物?支持生物技术的人也吃这种农产品吗?市场上的食品有多大比例含有转基因成分?
    答:过去几年中,美国消费者遭遇到很有声势的反生物技术的宣传运动,但根据问卷调查,有超过70%的人支持生物技术。比如,在最近俄勒冈州的一次全民公决中,选民们以73%对27%的压倒多数否决了在含转基因成分的食品上贴特殊标签的提议。这可能是因为消费者知道我们拥有有效的法规体系,很多人也可能知道超市货架上70%至80%的加工食品都含有一种或多种源于转基因作物的成分。几乎所有的美国人都吃转基因农产品,除了那些刻意寻找标明没有转基因成分的人。有证据表明,这样的人不到全体消费者的5%。

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