农业育种家通过常规杂交育种,培育选择了很多优良品种,但是这种方法耗费大量人力和需要很长时间,并且受到种和属间的局限性。自从七十年代起,在分子遗传学基础上,发展起来的生物高技术——基因工程,可以使目标更为集中,指定性地创造人们需要的某个新品种,如让作物品种具有量多质高的蛋白质,能抗虫 Agricultural breeders selected many fine varieties by conventional crossbreeding, but this method was labor-intensive and took a long time and was limited by species and genus. Since the seventies, based on molecular genetics, the developed biological high-tech-genetic engineering can make the target more concentrated and can definitely create a new variety that people need. For example, High-quality protein, insect-resistant