POPULATION GENETICS OF ARABIODOPSIS-THALIANA .1. BREEDING SYSTEM
POPULATION GENETICS OF ARABIODOPSIS-THALIANA .1. BREEDING SYSTEM
复制标题
DOI：
10.1038/hdy.1971.69
复制
发表时间：
1971-01-01
期刊：
影响因子：
3.8
通讯作者：
JONES, ME
中科院分区：
文献类型：
--
作者：
JONES, ME
拟南芥被广泛认为是一个完全近亲繁殖的物种（Muller，1961; Rédei，1962; Napp-Zinn，1964; Laibach，1965; Pederson，1968），这一结论主要是基于花的形态，认为花可以确保自花授粉。Muller（1961）进一步指出，近亲繁殖不会导致任何明显的近亲繁殖衰退。如果拟南芥是，这些观察表明，自花受精，那么这个物种的自然种群的遗传结构应该采取两种简单的形式之一。因此，要么这个群体除了突变之外是遗传上同质的，即所有个体都具有相同的纯合基因型，要么它包括一组异质的家庭，每个家庭都是纯合的。从其他物种的自然种群的工作中，几乎没有证据表明这两种类型的结构。Allard、Jam和Workman（1968）在一篇关于主要近亲繁殖种群遗传学的综述中，没有提到具有第一种种群结构的物种的例子，似乎只有一个物种的自然种群具有第二种结构的经过证实的例子（Fesuca microstachys; Kannenberg和Allard，1967; Allard和Kannenberg，1968）。另外，对以前被认为是专性近亲繁殖的物种的详细研究表明，确实发生了一些异花受精（Vasek，1964，1967; Allard，1965; Imam和Allard，1965; Allard，Jam和Workman，1968）。与前面讨论的两个种群不同，这类种群的特征是表现出家族内个体之间的遗传差异以及家族之间的遗传差异。Napp-Zinn（1964）的结果表明，拟南芥种群实际上是这类种群。他发现，来自自然群体的家系所表现出的变异大于自交系。这是一个结果，这是最简单的解释假设，前者是部分杂合的，因为异交发生在这个物种的自然群体。
Arabidopsis thaliana is widely regarded as a completely inbreeding species (Muller, 1961; Rédei, 1962; Napp-Zinn, 1964; Laibach, 1965; Pederson, 1968), a conclusion which is largely based on the morphology of the flowers which is thought to ensure self-pollination. Muller (1961) reports, furthermore, that inbreeding does not result in any obvious inbreeding depression. If Arabidopsis is, as these observations suggest, autogamous, then the genetic structure of natural populations of this species should take one of two simple forms. Thus, either the population is, mutation apart, genetically homo-geneous, ie all individuals are of the same homozygous genotype, or it comprises a heterogeneous set of families each of which is homozygous. There is little evidence from work on natural populations of other species of structures of either of these types. Allard, Jam and Workman (1968), in a review of the genetics of predominantly inbreeding populations, mention no example of a species with a population structure of the first type, and there appears to be only one authenticated case of a species whose natural popula-tions have a structure of the second kind (Fesuca microstachys; Kannenberg and Allard, 1967; Allard and Kannenberg, 1968). Otherwise, detailed studies on species previously believed to be obligate inbreeders have shown that some cross-fertilisation does occur (Vasek, 1964, 1967; Allard, 1965; Imam and Allard, 1965; Allard, Jam and Workman, 1968). Populations of this kind, unlike the two previously discussed, characteristically show genetic differences between individuals within a family as well as genetic differences between families.The results of Napp-Zinn (1964) suggest that Arabidopsis populations are in fact of this type. He found that the variation shown by families from natural populations is greater than that of inbred lines. This is an outcome which is most simply explained on the assumption that the former are partially heterozygous because outcrossing takes place in natural populations of this species.