玉米是天然异花授粉作物,在一般栽培条件下,异交率达90%以上,多的达到95%,自交率仅为5—10%左右。当种用的玉米植栋如不进行隔离或播前不进行穗选、粒选时,就很易引起混杂。品种混杂不同于杂交制种,杂交制种是有意识的选择两个优良亲本进行去雄(母本)杂交而成,使其提高产量和品质,而品种 Corn is a natural cross-pollination crops, under normal cultivation conditions, the out-crossing rate of more than 90%, more than 95%, self-fertility rate of only about 5-10%. When the planting of corn planting if not for isolation or sowing before the election, grain selection, it is easy to cause promiscuity. Variety hybrid is different from hybrid seed production, hybrid seed production is the conscious choice of two elite parents to male (female parent) hybridization made to increase yield and quality, and varieties