A field guide to models of sex-ratio evolution in gynodioecious species
A field guide to models of sex-ratio evolution in gynodioecious species
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DOI：
10.1111/j.0030-1299.2007.15315.x
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发表时间：
2007-10-01
期刊：
影响因子：
3.4
通讯作者：
Delph, Lynda F.
中科院分区：
文献类型：
--
作者：
Bailey, Maia F.;Delph, Lynda F.
雌雄异株植物物种，其中个体是雌性或雌雄同体的物种，是研究遗传学，生态学和长期进化变化之间联系的理想系统，因为性别决定可能是复杂的，涉及细胞质和/或核基因，性别比例通常在景观中变化。需要实地数据来评估有关这一育种系统的许多理论。为了便于收集相关数据，本文介绍了四种类型的雌蕊花型（核，核质和随机的雌蕊花型加上亚雌蕊花型），描述了示例物种和预期的模式，讨论了驱动雌性频率进化的各种力量，并给出了具体的建议，从哪里开始收集不同系统的数据。对于物种中，女性是相对罕见的，我们建议相互杂交，以确定性别决定是核或核质沿着与女性频率和生态因素之间的相关性搜索。对于物种中，女性是常见的，性别比是高度可变的，我们建议看看女性后代的性别比，以确定女性主要产生在短暂的epidemies.In这个讨论的过程中，我们认为，大多数自然gynodioecious物种将有复杂的性别决定，其中多个细胞质雄性不育（CMS）基因与多个核恢复生育力。这些物种的性比进化主要受雌雄同体之间的适应性差异（恢复成本）的影响，而受两性之间的适应性差异（补偿）的影响较小。集合种群动态本身就可以解释雌性与边缘环境或杂交区相关的物种的种群性别比;然而，我们认为，在大多数情况下，种群内的平衡力和种群之间的集合种群动态都可以解释部分性别比模式。
Gynodioecious plant species, species in which individuals are females or hermaphrodites, are ideal systems for studying connections between genetics, ecology, and long-term evolutionary changes because sex determination can be complex, involving cytoplasmic and/or nuclear genes, and sex ratio is often variable across landscapes. Field data are needed to evaluate the many theories concerning this breeding system. In order to facilitate the gathering of relevant data, this paper introduces the four types of gynodiocy (nuclear, nuclear-cytoplasmic and stochastic gynodioecy plus subdioecy), describes example species and expected patterns, discusses the various forces that drive the evolution of female frequencies, and gives concrete advice on where to start collecting data for different systems. For species in which females are relatively rare, we recommend reciprocal crosses to determine if sex-determination is nuclear or nuclear-cytoplasmic along with a search for correlations between female frequencies and ecological factors. For species in which females are common and sex ratios are highly variable, we recommend looking at female offspring sex ratios to determine if females are primarily produced in ephemeral epidemics.In the course of this discussion, we argue that the majority of natural gynodioecious species will have complex sex determination in which multiple cytoplasmic male sterility (CMS) genes interact with multiple nuclear restorers of fertility. Sex-ratio evolution in such species will be primarily influenced by fitness differences among hermaphrodites (costs of restoration) and less influenced by fitness differences between the sexes (compensation). Metapopulation dynamics alone may explain population sex ratios of species in which females are associated with marginal environments or hybrid zones; however, we feel that in most cases equilibrium forces within populations and metapopulation dynamics among populations each explain portions of the sex-ratio pattern.