植物开花时间: 自然变异与遗传分化

开花时间是植物的重要生活史性状。对模式植物的研究表明: 从感受内外环境信号开始到最终分化形成功能性花器官的过程涉及复杂的信号转导途径和调控网络; 开花时间受多种因子的调控, 而FT基因作为整合途径成分起到非常关键的作用。植物的花期变异在物种、群体和个体水平上具有复杂的自然变异模式, 且不同植物的花期变异随全球环境变化而具有不同的变异趋势。植物个体之间通过传粉进行的基因交流需要功能性开花时间的一致或重叠, 而花期变异会导致群体之间或群体内部亚群体之间的基因流障碍和遗传分化, 并可能导致邻域或同域的物种形成。该文分析了植物花期变异与群体遗传分化的关系, 认为决定开花时间的基因在物种分化中可能起到关键的作用, 而对开花时间自然变异模式的研究对于揭示晚近分化快速辐射物种的进化模式具有重要意义。

Plant Flowering Time: Natural Variation in the Field and Its Role in Determining Genetic Differentiation

Flowering is an important transition from vegetative to reproductive development in the plant life cycle; the determination of flowering time is an important component of flower development. A complicated genetic network involved in the perception of various signals from external environmental cues or internal developmental signs is involved in the complicated developmental process of flower organs. FT gene, encoding protein acting as mobile messenger, is the main integrator in this genetic network. Flowering time is affected by components of signal perception such as CO, GI, FLC and FRI. Flowering time of various plant species has sophisticated expression in the field. Global change, especially global warming, has diverse effects on flowering time for various plant species. Accordance or overlapping of flowering time is important for gene flow among individual plants. Temporal isolation, which originates from the variation in flowering time, could result in the genetic differentiation between parapatric populations or sympatric subpopulations.