生产和推广高质量的原种,是农业生产中投资少、见效快、收益大的一项重要措施。一个优良品种在生产上大面积推广几年之后,由于环境、机械、人为混杂及天然杂交等多种因素的影响,造成退化,因此必须连续不断的进行提纯复壮,以保持良种的纯度和种性,使其在生产上长时间发挥增产作 The production and promotion of high-quality seeds are an important measure of less investment, quick returns and large profits in agricultural production. A good variety in the production of a large area to promote a few years later, due to environmental, mechanical, artificial hybrid and natural hybridization and other factors, resulting in degradation, it must be continuous purification and rejuvenation in order to maintain the purity and species of the elite , So that in production for a long time to increase production for