林木改良中育种群的概念应用和发展

BREEDING GROUPS: THE CONCEPT, APPLICATIONS, AND DEVELOPMENT IN FOREST AND TREE IMPROVEMENT

育种群是组成整个育种群体的多个亚群体,其意义相当于农作物育种的近交系。在美国的一些林木育种项目中,育种群已用来控制种子园的近交、捕获最大的遗传增益的有效措施。育种群的建立不会改变各群内的育种值,但每个育种群内的遗传变异会随近交系数的增加而增加,这为我们在群内选优提供了更大的选择余地。此外,建立育种群只增加一些档案记录工作,并不增加野外工作量。

Breeding groups, subdivisions of a breeding population composed of superior individuals, are equivalent to inbred lines in crop breeding. Breeding groups are being used to control inbreeding in a breeding population and to effectively achieve maximum genetic gains in some tree improvement programs of the United States. The use of breeding groups does not change the breeding values of the subdivided populations. The genetic variance of breeding values within a breeding group, however, will be increased depending on the degree of inbreeding in each group. Such variance change will increase the total genetic variation and offer a better chance for selection of desirable genotypes for successive generations of breeding groups. Furthermore, breeding groups will add only paper work to keep records separate for a tree improvement program manager, but they can be easily implemented in a forest tree improvement program without extra field work.