Modeling gynodioecy: Novel scenarios for maintaining polymorphism
Modeling gynodioecy: Novel scenarios for maintaining polymorphism
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DOI：
10.1086/374803
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发表时间：
2003-05-01
影响因子：
2.9
通讯作者：
Lively, CM
中科院分区：
文献类型：
--
作者：
Bailey, MF;Delph, LF;Lively, CM
核质型雌核双育是一种雌雄同体的植物育种系统，其性别由细胞质雄性不育基因和核恢复基因共同决定。在CMS和核恢复基因座的持续多态性是必要的，以维持这一育种系统。理论模型已经解释了核质雌蕊异育体在某些假设下是如何稳定的。然而，最近的进展，在我们的理解的遗传学，种群生物学，和核质雌雄异株物种的性别决定的分子机制，建议实用的新模型与不同的基本假设。在这篇文章中，我们研究了不同的负多效性的健身效果的核恢复（恢复成本）使用遗传和人口假设的基础上，最近的文献。具体来说，我们的模型人口与两个CMS类型和单独的核恢复基因座为每个CMS类型。在这些假设下，无论是超显性的健身和频率依赖性选择在核恢复基因座可以支持核质gynodiotomy。恢复的成本可以是依赖或独立的细胞质背景。种子健身成本更容易固定CMS类型比花粉成本。生存成本是有效的，即使在维持多态性的总生殖效果很低。总的来说，我们的模型显示核质gynodiopathy的稳定性和预测的人口性别比，应该是在野外研究gynodiopathy的研究人员提供信息的差异。
Nuclear-cytoplasmic gynodioecy is a breeding system of plants in which females and hermaphrodites co-occur in populations, and gender is jointly determined by cytoplasmic male sterility (CMS) genes and nuclear restorers of male fertility. Persistent polymorphism at both CMS and nuclear-restorer loci is necessary to maintain this breeding system. Theoretical models have explained how nuclear-cytoplasmic gynodioecy can be stable for certain assumptions. However, recent advances in our understanding of the genetics, population biology, and molecular mechanisms of sex determination in nuclear-cytoplasmic gynodioecious species suggest the utility of new models with different underlying assumptions. In this article, we examine different negative pleiotropic fitness effects of nuclear restorers (costs of restoration) using genetic and population assumptions based on recent literature. Specifically, we model populations with two CMS types and separate nuclear restorer loci for each CMS type. Under these assumptions, both overdominance for fitness and frequency-dependent selection at nuclear-restorer loci can support nuclear-cytoplasmic gynodioecy. Costs of restoration can be either dependent or independent of the cytoplasmic background. Seed fitness costs are more vulnerable to fixation of CMS types than pollen costs. Survivorship costs are effective at maintaining polymorphism even when total reproductive effects are low. Overall, our models display differences in the stability of nuclear-cytoplasmic gynodioecy and predicted population sex ratios that should be informative to researchers studying gynodioecy in the wild.