玉米杂交种的培育过程是杂种优势模式的发展过程，也是杂种优势群的变化过程，杂种优势群和杂种优势模式并不是一成不变的。从美国杂种优势群的发展与演变出发，分析瑞德黄马牙（Reid Yellow Dent）和衣阿华坚秆综合种（BSSS）的起源和历史地位以及衣阿华瑞德黄马牙（Iodent Reid）在美国玉米育种中的历史变迁，认为衣阿华坚秆综合种属瑞德黄马牙种质，衣阿华瑞德黄马牙虽在起源和遗传构成上也均属于瑞德黄马牙，但其杂种优势群已经属于Non-BSSS，与衣阿华坚秆综合种（BSSS）形成两个相对应的杂种优势群，成功培育出一系列商业杂交种。因此应将美国玉米种质中的BSSS与Reid加以区分。

Heterosis population and heterosis utilization model were not permanent. In fact, the procedure of the maize hybrids breeding involved both developing processes of heterosis utilization model and changing processes of heterosis population. According to the development and transformation of American heterosis population, the origin and history importance of the Reid Yellow Dent and BSSS population were analyzed as well as the evolution process of Iodent Reid in American maize breeding history. The results showed that BSSS belonged to the Reid Yellow Dent germplasm. Based on the origin and genetic structure, Iodent Reid also belonged to the Reid Yellow Dent germplasm, but fell into the non-BSSS by the heterosis. It formed another opposite heterosis population of the BSSS and was used into a series of maize commercial breeding.

陕西省科技统筹项目（2011KTZB02-01-02）