CHLOROPLAST DNA AND ISOZYME DIVERSITY IN 2 MIMULUS SPECIES (SCROPHULARIACEAE) WITH CONTRASTING MATING SYSTEMS
CHLOROPLAST DNA AND ISOZYME DIVERSITY IN 2 MIMULUS SPECIES (SCROPHULARIACEAE) WITH CONTRASTING MATING SYSTEMS
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DOI：
10.2307/2445145
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发表时间：
1992-12-01
影响因子：
3
通讯作者：
RITLAND, K
中科院分区：
文献类型：
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作者：
FENSTER, CB;RITLAND, K
比较了混合交配型M. guttatus及其高度自交的同类M.（玄参科）。与M相比。micranthus、小花M.在全物种水平上，guttatus的cpDNA和同工酶变异的多样性高出2 - 4倍。自交M.小花矮牵牛的居群内等位酶变异也低1.5 ~ 3倍，而且其变异分布在居群间而不是居群内的比例较大。叶绿体DNA在这里被推断为单亲遗传。因此，交配系统对叶绿体基因组的传递没有影响。由于叶绿体DNA和同工酶变异在M. micranthus，交配系统以外的因素被推测是负责观察到的物种范围内的遗传变异减少M。小花M. micranthus从数量有限的M.建议使用Guttatus种群。因此，M中的分子变异减少。由于瓶颈效应，这些数据一般表明，在某些物种中，cpDNA变异的水平可能足够高，可以推断物种水平以下的进化过程。
Levels of cpDNA and isozyme diversity were contrasted between the mixed-mating M. guttatus and its highly selfing congener M. micranthus (Scrophulariaceae). Compared to M. micranthus, M. guttatus has two to four times higher diversity for both cpDNA and isozyme variation on a species-wide level. The selfing M. micranthus also has 1.5 to three times lower within-population allozyme variation and a greater proportion of its variation distributed among rather than within populations. Chloroplast DNA is here inferred to be uniparentally inherited. Thus the mating system has no effect on the transmission of the chloroplast genome. Since both cpDNA and isozyme variation are similarly reduced in M. micranthus, factors other than the mating system are hypothesized to be responsible for the observed decrease in species-wide genetic variation in M. micranthus. A recent origin of M. micranthus from a limited number of M. guttatus populations is suggested. Consequently, molecular variation is reduced in M. micranthus due to a bottleneck effect. These data generally demonstrate that levels of cpDNA variation may be high enough in some species to infer evolutionary processes below the species level.