作为微进化现象的一个缩影，过渡相种群交配网络格局特征对于理解物种性状演替过程具有重要意义。构成花部综合征的繁殖性状在表型间的适合度差异能够在过渡相种群内的交配环节中获得体现，它使得多态的性表型受到快速而强烈的定向选择作用而表现为花型转变现象。在进化的时间尺度上，性表型相关的过渡相种群可谓转瞬即逝，因此少数包含性状过渡相特征的表型多态类群是开展性状演替研究的理想素材。本项目选用中甸灯台报春，利用该物种具备二型花柱向同型花柱转变的典型特征；通过构建一系列性比的人工种群和父本推断的方法，重点围绕性状演替的内部生理遗传因素、外部生态环境促成条件，以及在进化时间尺度上性系统转变与类群盛衰的关系等三方面问题，开展进化生态学研究。项目的实施有望为异型与同型花柱之间的演化转变提供新的证据；同时，从植物性系统演替与分化的层面上加深理解喜马拉雅-横断山区报春花属及其相关类群的物种多样性发生与维持机制。

The feature of mating patterns in transitional population is of great significance for understanding the succession process of floral characters in the way of microevolutionary trajectory. As part of the floral syndrome, fitness difference between floral morphs can be reflected in the mating process, and therefore the sexual polymorphism is more like to undergo rapid and intense direntional selection resulting morphological transition. The group containning transition phase polymorphism provides an unsual opportunity to address several questions of general relevance to the breakdown of heterostyly to homostyly, since the transition phase of phenotypic population was ephemeral in the evolutionary time scale. . Primula chungensis is of particular interest because it is a species with both distylous and homostylous populations and even the trimorphic populations in which all three morphs coexist. This species therefore provides a rare example of the replacement of sexual polymorphism by floral monomorphism in a heterostylous species. By investigating mating patterns of artificial populations with different floral morph ratios inferred from paternity analysis, we address the following questions: First, what are the most important factors that determine the initial progress of newly occurring homostyles? Second, to what extent are the morph ratio and pollinator environment important for patterns of mating in transitional population? Finally, we aim to determine whether the transition of mating system from out crossing to selfing accounts for the dynamic of species diversity in a particular distylous-homostylous taxa. This project will provide novel insights into how and why distyly breaks down to homostyly and the ecological and genetic consequences of this transition. In addition the sexual polymorphic component of the study will provide valuable information on the role of ecological and genetic factors influencing the origin and maintenance of primula species in Himalaya-Hengduan Mountains Region.