关键词: 玉米, 杂种优势, 遗传距离, 优势群, 产量

Abstract: Fourteen maize (Zea mays L.) inbred lines and their nonreciprocal diallel crosses were evaluated in 1991 in Sichuan. Chassification of the inbred lines was done respectively by using yield heterosis from midparent and genetic distance. The lines were divided into four heterotic groups according to yield heterosis, the groups accorded with parentage of the lines and breeder's experience. There were higher yield heterosis among the heterotic groups, and there were bigger cotnpining ability difference among the lines of each group for silking date, plant height and yield. Genetic distance was not related to yield heterosis, it should be prudent to use it in classification of maize parental germplasm. The ways and problems on utilization of heterotic groups in breeding progrm were also discussed.

Key words: CRON, HETEROSIS, GENETIC DISTANCE, HETEROTTC GROUP, YIELD