Lin J Z, Ritland K
Department of Botany, University of Toronto, Ontario, Canada.
Genetics. 1997 Jul;146(3):1115-21. doi: 10.1093/genetics/146.3.1115.
Theoretical predictions about the evolution of selfing depend on the genetic architecture of loci controlling selfing (monogenic vs. polygenic determination, large vs. small effect of alleles, dominance vs. recessiveness), and studies of such architecture are lacking. We inferred the genetic basis of mating system differences between the outbreeding Mimulus guttatus and the inbreeding M. platycalyx by quantitative trait locus (QTL) mapping using random amplified polymorphic DNA and isozyme markers. One to three QTL were detected for each of five mating system characters, and each QTL explained 7.6-28.6% of the phenotypic variance. Taken together, QTL accounted for up to 38% of the variation in mating system characters, and a large proportion of variation was unaccounted for. Inferred QTL often affected more than one trait, contributing to the genetic correlation between those traits. These results are consistent with the hypothesis that quantitative variation in plant mating system characters is primarily controlled by loci with small effect.
关于自交进化的理论预测取决于控制自交的基因座的遗传结构（单基因与多基因决定、等位基因的大效应与小效应、显性与隐性），而目前缺乏对此类结构的研究。我们通过使用随机扩增多态性DNA和同工酶标记进行数量性状位点（QTL）定位，推断了异交的沟酸浆属植物和自交的宽萼沟酸浆属植物之间交配系统差异的遗传基础。对于五个交配系统性状中的每一个，检测到1至3个QTL，每个QTL解释了7.6 - 28.6%的表型变异。总体而言，QTL占交配系统性状变异的比例高达38%，且很大一部分变异无法得到解释。推断出的QTL通常会影响不止一个性状，从而导致这些性状之间的遗传相关性。这些结果与植物交配系统性状的数量变异主要由小效应基因座控制这一假设一致。
