任何一个棉花品种,在刚推广种植时,其生物学性状(如株型、叶型、铃型等)和经济性状(衣分的高低、纤维的长短……)都表现大体整齐一致。但在生产上,随着推广面积的扩大,栽培年限的延长,很容易混杂退化,从而导致产量和纤维品质的降低。可见研究解决棉花品种的保纯,是关系到棉花生产能否迅速发展和商品率高低的大问题。一、棉花品种的保纯势在必行棉花是常异交作物,遗传基础复杂,加之生产过程中环节多,容易混杂分离产生退化,使品种原有的遗传组成发生变异,失去原有的优良性状。据调查,1957年在山东省德州地区开始推广岱字棉15号时测定, The biological traits (such as plant type, leaf type, bell type, etc.) and economic traits (the level of the lint, the length of the fiber, etc.) of any one cotton variety have generally showed the same regularity when they were just popularized. However, in terms of production, with the extension of the popularization area and the prolongation of the cultivation period, it is easy to degenerate and deteriorate, resulting in the decrease of yield and fiber quality. It can be seen that studying and solving the problem of maintaining pure cotton varieties is a big issue that relates to the rapid development of cotton production and the high and low rate of commodity production. First, the purity of cotton varieties is imperative Cotton is often outcrossing crops, the genetic basis of complex, coupled with many links in the production process, easy to separate mixed produce degradation, so that the genetic variability of the original varieties, loss of the original fine Traits. According to the survey, in 1957 in Dezhou, Shandong Province began to promote Dai word cotton measured at 15,