玉米自交系生活力弱,单株生产潜力小,即在较高的肥水条件下,自交系果穗变化幅度不大,故单位群体大小对产量关系极大.必须适当增加亩植株数,合理密植并适当扩大母本行比,才能不断提高制种产量.针对制种组合亲本的持点(植株高矮、株型松散等)和父本花粉量的多少,结合自然条件和耕作制 Maize inbred lines have weaker vigor and lower potential for single plant production, that is, under the condition of relatively high fertilizer and water, the ear size of inbred lines is not greatly changed, so the size of unit groups has a great relationship with the yield. Close planting and appropriate expansion of the ratio of the mother of the line, in order to continuously improve the production of seed production.Parenting point for the combination of parents (plant height, loose type, etc.) and the amount of male parent pollen, combined with natural conditions and farming system