玉米人工合成群体的改良与利用

回顾国内外玉米群体改良利用研究的概况,分析四川农业大学在玉米群体合成、改良与利用方面开展的研究及取得的主要成果,结合玉米育种发展趋势,对进一步提高玉米群体改良利用效率提出思路。就研究方法和内容而言,应将传统方法和现代分子生物学技术结合,重点研究群体农艺性状及配合力表现、遗传多样性、杂种优势和遗传组成等,探明群体育种潜势;合成群体时,应按杂优类群选择自身性状优良、配合力高且彼此又有一定差异的材料,以适当协调群体的遗传异质性与群体内优良个体出现频率两者的矛盾,在对群体遗传育种潜势评价的基础上,应针对群体存在的问题,确定好选择目标性状和选择强度,并利用适当的轮回选择方法进行改良,以提高玉米群体改良利用效率;在群体改良过程中,应定期进行群体改良效果评价,以便根据评价结果及时调整改良方案;在利用人工合成改良群体选系前,应对群体的育种潜势进行评价,并根据群体遗传特性和自交后代配合力表现,采取相应的策略和方法。

The Improvements and Utilizations of Synthetic Maize Population

The improvement and utilization on maize populations in the world were reviewed. For the syntheses, improvement and utilization of maize populations, surveys conducted in Sichuan agricultural university were introduced. Additionally, suggestions on how to raise the efficiency of improvement and utilization of synthetic populations were made, based on the development of maize breeding. In order to insight into the breeding potentiality of the populations, we should pay attention to investigation in their germplasm characteristics such as agronomic traits, genetic diversity, combining ability, heterosis, and genetic effect, by both the traditional breeding method and modern biotechnologies. Those germplasm materials with high combining ability, good performance and genetic variation should be used to synthesize maize populations in terms of the heterosis patters, and then they based on evaluations on the breeding potentiality, could be improved by recurrent selections with moderate selection intensity. The improvement effects of the populations should be analysis periodically, then adjusted the improvement program according to the results. Before the synthetic maize populations were used to derive inbred lines, their breeding potentiality should be evaluated and different strategies and methods advised according to the genetic trait of populations and the combing ability of their pedigrees.