美国抗虫棉研究新进展美国已将一种外源基因植入棉花并得到了表达，赋予整个植株以新的特性。科学家正在研究减少棉花对农药的依赖性，试图用遗传工程培育能自行分泌天然杀虫毒素的棉花植株。但是截止目前，他们尚未确定这些棉花植株是否表达出杀虫毒性。如果得出肯定的结... New Progress in Research on Bt-Resistant Cotton in the United States The United States has implanted and expressed a foreign gene in cotton, giving the whole plant new characteristics. Scientists are studying ways to reduce the cotton’s dependence on pesticides and trying to breed cotton plants capable of secreting natural insecticidal toxins by genetic engineering. But so far, they have not yet determined if these cotton plants express insecticidal toxicity. If you get a positive knot ...