QUANTITATIVE GENETICS OF MATING SYSTEM DIVERGENCE IN THE YELLOW MONKEYFLOWER SPECIES COMPLEX
QUANTITATIVE GENETICS OF MATING SYSTEM DIVERGENCE IN THE YELLOW MONKEYFLOWER SPECIES COMPLEX
复制标题
DOI：
10.1038/hdy.1994.190
复制
发表时间：
1994-10-01
期刊：
影响因子：
3.8
通讯作者：
RITLAND, K
中科院分区：
文献类型：
--
作者：
FENSTER, CB;RITLAND, K
为了研究与黄色猴花（Mimulus，Simiolus 组）交配系统分歧相关的花性状表型变化的遗传基础，所有成对杂交均在四个分类群之间进行，其中两个是独立进化的近交系。使用包含显性的模型，根据回交和 F-2 分离方差估计了区分六个性状中每一个的分类群的遗传因素的有效数量。类群对的平均因子数量范围为 5.3（柱头花药分离）到 12.8（雌蕊长度）。对于大多数性状来说，显性程度是轻微到中等的，近交特征稍微偏向于远交特征。 F-2分离模式表明花大小性状之间有很强的遗传相关性，但这些性状与开花时间的相关性可变，与柱头花药分离的相关性很小。两个自交和两个异交类群之间的杂交并没有导致 F-2 中极端海侵分离体的恢复。这些结果表明，要么同源基因座参与自交的重复转变，要么出现新重组的可能性受到大量基因座的限制，每个基因座的影响都很小。这些结果的含义在最近的交配系统进化模型的背景下进行了讨论。
To study the genetic basis of phenotypic changes in floral characters associated with mating system divergence in the yellow monkeyflowers (Mimulus, section Simiolus), all pairwise crosses were conducted between four taxa, of which two were independently evolved inbreeders. The effective number of genetic factors differentiating taxa for each of six characters was estimated from backcross and F-2 segregation variances, using a model that incorporates dominance. The number of factors, averaged over taxa pairs, ranged from 5.3 (for stigma-anther separation) to 12.8 (for pistil length). Dominance was slight to moderate for most characters, with a slight bias for inbreeding characteristics to be dominant over outbreeding traits. F-2 segregation patterns indicate strong genetic correlations among floral size characters but variable correlation of these characters with flowering time and little correlation with stigma-anther separation. Crosses between the two selfing and two outcrossing taxa did not lead to the recovery of extreme transgressive segregants in the F-2. These results suggest that either homologous loci are involved in repeated shifts to selfing or that the likelihood of appearance of novel recombinations is limited by the large number of loci, each with small effect. The implications of these results are discussed in the context of recent models of mating system evolution.