EFFECTS OF DIFFERENT LEVELS OF INBREEDING ON FITNESS COMPONENTS IN MIMULUS GUTTATUS
EFFECTS OF DIFFERENT LEVELS OF INBREEDING ON FITNESS COMPONENTS IN MIMULUS GUTTATUS
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不同近交水平对鹩莺适应性成分的影响
DOI：
10.1111/j.1558-5646.1993.tb01240.x
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发表时间：
1993
期刊：
影响因子：
3.3
通讯作者：
J. Willis
中科院分区：
文献类型：
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作者：
J. Willis
最近的理论研究表明，当不同位点的有害突变协同作用时，可能存在有利于维持有性生殖和增加重组进化的选择，因此适应度的对数随着每个基因组的有害突变数量以大于线性的速率下降。本实验研究的目的是确定两个部分自交猴花（Mimulus guttatus）群体中影响适合度成分的基因是否存在协同作用。在每个野生种群中，随机构建一个大的基础种群，并从这个基础种群中提取出许多不同程度的自交系。预期近交系数为0、0.25、0.5和0.75的系在温室中同时培养，并对萌发、开花、开花和花粉活力进行评分。除种子萌发成功率外，所有适合度性状均随近交的增加而下降，但尽管本研究中发现了大量近交抑制，但发现的协同上位性证据相对较少。唯一显示出协同作用证据的性状是花粉活力。这些结果表明，本研究测量的健身成分的协同作用不强。本文还回顾了其他已发表的研究中关于协同作用的证据。
Recent theoretical work has shown that there can be selection favoring the maintenance of sexual reproduction and the evolution of increased recombination when deleterious mutations at different loci interact synergistically, such that the logarithm of fitness declines at a greater than linear rate with the number of harmful mutations per genome. The purpose of this experimental study was to determine whether synergism exists for genes affecting fitness components in two partially selfing populations of the monkey flower Mimulus guttatus. For each wild population, a large randomly mated base population was constructed and many independent lines, inbred to differing degrees, were extracted from this base population. Lines with expected inbreeding coefficients of 0, 0.25, 0.5, and 0.75 were raised simultaneously in the greenhouse and were scored for germination, flowering, flower production, and pollen viability. All fitness traits except germination success declined with increased inbreeding, but in spite of the substantial inbreeding depression found in this study, relatively little evidence of synergistic epistasis was found. The only trait that showed evidence of synergism was pollen viability. These results indicate that synergism is not strong for the fitness components measured in this study. The evidence for synergism from other published studies is also reviewed.