GENETIC CHANGES ASSOCIATED WITH THE EVOLUTION OF ADAPTEDNESS IN CULTIVATED PLANTS AND THEIR WILD PROGENITORS
GENETIC CHANGES ASSOCIATED WITH THE EVOLUTION OF ADAPTEDNESS IN CULTIVATED PLANTS AND THEIR WILD PROGENITORS
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DOI：
10.1093/oxfordjournals.jhered.a110503
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发表时间：
1988-07-01
影响因子：
3.1
通讯作者：
ALLARD, RW
中科院分区：
文献类型：
--
作者：
ALLARD, RW
总结了一些一年生植物实验种群适应性变化的长期研究结果。对数量性状的测量表明，这些实验种群的繁殖能力持续累积增长超过 50 代。控制形态变异、抗病性、等位酶和 rDNA 限制片段的标记位点也发生了高度显着的等位基因频率变化。标记基因座对数量性状的个体影响是通过对从实验群体的各代分离的单一植物衍生的自交家族的广泛后代测试来确定的。数量性状表达的标记位点纯合子和杂合子之间的比较表明，所有研究的标记位点对多个至多个数量性状均具有统计学上显着的加性效应；因此，每个孟德尔基因座除了是其离散描述效应的基因座之外，也是几个数量性状的基因座。在优越的繁殖能力（例如，每株植物的籽粒数量较多）和标记基因座的等位基因之间发现了一致的关联，这些等位基因的频率随着世代的增加而增加；没有其他测量的数量性状与频率增加的等位基因明确且一致地相关。基于典型相关、对数线性和聚类分析程序的多位点分析表明，在所研究的所有主要自交群体中，不同位点的等位基因之间在早期世代中形成了高度显着的关联。以等位基因合并为较少簇、涉及大量基因座的动态变化持续到后代。人们发现，在主导销售下形成的生态遗传分化模式是环境异质性的精细覆盖。出现的进化变化图景是，越来越多的有利相互作用的等位基因融入大型协同复合体中，伴随着近交种群对当地环境适应性的增强，以及占据不同栖息地的当地种群之间显着的生态遗传分化，包括栽培植物与其野生祖先之间的分化。自交似乎促进种群内适应性的发展和维持，同时通过阻碍种群之间的基因流动来促进空间分化的发展。近交种群的适应性变化模式虽然在大多数细节上与近交种群相似，但其特征是种群内的多位点结构组织不太明显，种群之间的生态地理分化也不太明显。
The results of long-term studies of changes in adaptedness in a number of experimental populations of annual plants are summarized. Measurements made of quantitative traits showed that cumulative increases in reproductive capacity continued in these experimental populations for more than 50 generations. Highly significant allelic frequency changes also occurred for marker loci governing morphological variants, disease resistance, allozymes, and rDNA restriction fragments. Individual effects of the marker loci on quantitative traits were determined by extensive progeny testing of selfed families descended from single plants isolated from various generations of the experimental populations. Comparisons between homozygotes and heterozygotes of marker loci for quantitative trait expression revealed that all the marker loci studied had statistically significant additive effects on several to many quantitative traits; thus, each Mendelian locus, in addition to being a locus for its discrete descriptive effect, was also a locus for several quantitative traits. Consistent associations were found between superior reproductive capacity (e.g., larger numbers of kernels per plant) and the alleles of marker loci that Increased in frequency over generations; no other quantitative traits measured were clearly and consistently associated with alleles that increased in frequency. Multilocus analyses based on canonical correlation, log linear, and cluster analysis procedures showed that highly significant associations developed in early generations among alleles of different loci in all the predominantly selfing populations studied. Dynamic changes featuring amalgamations of alleles into fewer clusters involving larger numbers of loci continued into the late generations. Patterns of ecogenetic differentiation that developed under predominant selling were found to be fine-scaled overlays of environmental heterogeneity. The picture of evolutionary change that emerges is one in which the incorporation of Increasing numbers of favorably interacting alleles into large synergistic complexes was accompanied in inbreeding populations by increases in adaptedness to the local environment and also by striking ecogenetic differentiation among local populations that occupy unlike habitats, including differentiation between cultivated plants and their wild progenitors. Selfing appears to promote the development and maintenance of adaptedness within populations and at the same time to facilitate the development of spatial differentiation by retarding gene flow between populations. Patterns of adaptive change in outbreeding populations, although similar to those of inbreeders in most particulars, featured less distinct multilocus structural organization within, as well as much less distinct ecogeographical differentiation among, populations.