Sexual expression and reproductive output in the ephemeral Geranium transversale are correlated with environmental conditions
Sexual expression and reproductive output in the ephemeral Geranium transversale are correlated with environmental conditions
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短命天竺葵的性表达和繁殖输出与环境条件相关
DOI：
10.3732/ajb.1700258
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发表时间：
2017-12-01
影响因子：
3
通讯作者：
Chang, Shu-Mei
中科院分区：
文献类型：
--
作者：
Abdusalam, Aysajan;Tan, Dunyan;Chang, Shu-Mei
研究前提：非生物环境因素通常被认为是开花植物性别系统变异分布和维持的重要因素。在雌雄异株系统中，性别和非生物因素之间的关联已被充分记录，但在其他性多态系统中，这种关系鲜为人知。在性表达和生境分布上高度可变的物种可以提供非生物因素在维持性表达变化中的作用的见解。方法：以两性多态的天竺葵（Geranium transversale）为研究对象，在花和植株水平上测量了性表达，并研究了营养和花的性状、花粉沉积和繁殖成功率。我们还测试了性表达与其他性状之间的相关性，并研究了这些性状是否以及如何与非生物环境条件共同变化。关键结果：我们在G .transversale中发现了独特的性表达变异。三种花类型（雌蕊花、雄蕊花和完全花）的不同组合有四种性别形态。在更潮湿和更温和的环境中，雌性表型更明显的性形态（即雌性和雌雄同株型）比雄性表型更早开花（即雌雄同体和雌雄同株型）。此外，花器官大小和繁殖成功不仅受花类型的影响，还受植物性形态的影响。结论：环境条件可能会导致横纹草性表达的一些变化。遗传和生态因素可能都有助于维持该物种的性别变异。
PREMISE OF THE STUDY: Abiotic environmental factors are often considered to be important in the distribution and maintenance of variation in sexual systems in flowering plants. Associations between sexes and abiotic factors are well documented in dioecious systems, but much less is known about this relationship in other sexually polymorphic systems. Species that are highly variable in sexual expression and habitat distribution can provide insights into the role of abiotic factors in maintaining variation in sexual expression.METHODS: Focusing on a sexually polymorphic species, Geranium transversale, we measured sexual expression at both the flower and the plant level and examined vegetative and floral traits, pollen deposition, and reproductive success. We also tested for correlations between sexual expression and other traits and examined whether and how these traits covaried with abiotic environmental conditions.KEY RESULTS: We identified unique variation of sexual expression in G .transversale. There are four sexual morphs that display different combinations of the three flower types (pistillate, staminate, and perfect). Sexual morphs that are phenotypically more female (i.e., female and gynomonoecious morphs) are found in wetter and milder environments, and flower earlier than morphs that are more male (i.e., hermaphroditic and andromonoecious morphs). Additionally, floral organ size and reproductive success are influenced not only by the flower type but also by the sexual morph of the plant.CONCLUSIONS: Environmental conditions are likely to cause some of the variation in sexual expression found in G. transversale. Both genetic and ecological factors likely contribute to the maintenance of sexual variation in this species.