Reevaluation of reproductive strategies and mating system of insect-pollinated plants from the viewpoint of pollen dispersal patterns

为了验证动物授粉植物的花部结构和开花模式的多样性可能是通过雄性功能（授粉过程）来提高繁殖成功率的假设，我们研究了花部性状与传粉者介导的花粉流动的关系，以及昆虫授粉植物的授粉效率与育种系统的关系。在控制条件下使用人工花序进行的授粉实验表明，花蜜在花序内的分布、花序结构和花（和花序）密度有效地影响传粉者的行为，从而导致植物的授粉效率。通过对自然条件下不同昆虫传粉植物的传粉状况和繁殖系统的观察和调控，发现：（1）改变花色可以作为一种传粉策略，通过控制植物内部连续访花次数来减少异花授粉;（二）雌雄同体花的花的性别分配在花序内的花之间存在差异，这取决于传粉者具有不同的传粉效率，（3）由于传粉者活动的季节性变化，开花物候的变化有时会导致不同的传粉效率和后代的遗传多样性，（4）蜜蜂传粉的物种在结实成功率方面可能比苍蝇传粉的物种具有更高的时空波动，因为蜜蜂通常比苍蝇更容易受到气候条件的影响，（5）克隆生长可能会加速同株分株间的异花授粉，从而降低异交结实量，表明克隆生长与有性生殖之间存在着一种权衡关系。这些结果表明传粉过程对昆虫传粉植物的繁殖成功和种群增长的重要性。

To test the hypothesis that diverse floral structures and flowering patterns of animal-pollinated plants may have developed to enhance the reproductive success through male function, i.e. pollination process, we investigated the relationships between floral traits and pollinator mediated pollen flow, and the relationships between pollination efficiency and breeding system of insect-pollinated plants. The pollination experiment using artificial inflorescences under controlled conditions revealed that nectar distribution within inflorescences, inflorescence structure, and floral (and inflorescence) densities effectively influence the pollinator behavior, resulting in pollination efficiency of plants. Observation and manipulations of the pollination situation and breeding systems of various insect-pollinated species under natural conditions revealed that (1) floral color change can be a pollination strategy to reduce the geitonogamous pollination by controlling the number of successive flower visits within plants, (2) floral sex allocation of hermaphrodite flowers varies among flowers within inflorescences differently between populations depending on the type of pollinators having different pollination efficiencies, (3) variations in flowering phenology sometimes cause different pollination efficiency and genetic diversity of progenies due to the seasonal variations in pollinator activity, (4) bee-pollinated species may have higher spatiotemporal fluctuations in seed-set success than fly-pollinated species, because bees usually more susceptible to the climatic conditions than flies, and (5) clonal growth may decrease the outcrossing seed production due to acceleration of geitonogamous pollination among ramets within same genet, indicating a trade-off between clonal growth and sexual reproduction. These results indicate the importance of pollination process for reproductive success and population growth of insect-pollinated plants.