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一、前言毕节地区是我省玉米主产区,播种面积及总产量均占全区粮食作物的第一位,但仍以地方品种为主要栽培种,单产水平低,七十年代平均单产才332.6斤。因此,大力开展杂种优势的利用,积极选育适合我区大面积栽培的杂交组合,对提高玉米产量,具有重要现实意义。玉米杂种优势的利用,如顶交、单交、三交、双交等杂交组合,它们的亲本来源均离不开自交系。没有组配能力强的亲本自交系材料,不可能育出优良的杂交组合。十几年的实践告诉我们,单纯利用外地自交系组配,一方面资源单一化,种质贫泛,组合优势没有新的突破。
I. INTRODUCTION Bijie Prefecture is the main corn producing area in our province. The sown area and total output all occupy the first place among all the food crops in the region. However, Bifidun is still the main cultivars with a low yield level. The average yield in the 1970s was 332.6 jin. Therefore, to vigorously carry out the utilization of heterosis, and actively breeding hybrids suitable for large-area cultivation in our region, to improve the yield of corn, has important practical significance. Maize heterosis utilization, such as the top cross, single cross, three cross, double cross and other hybrid combinations, their parents are inseparable from the inbred lines. It is impossible to breed good hybrid combinations without the ability to compose the parental inbred lines. More than a decade of practice tells us that the simple use of field inbreds with the deployment of resources on the one hand, the germplasm is poor, there is no new breakthrough in combination advantages.