蝶形花亚科植物花部适应机制与传粉系统

蝶形花亚科(Papilionoideae)植物种类丰富、繁育系统多样,与其传粉者关系密切,主要表现在花部适应与传粉系统的形成。蝶形花形态复杂,为完全花,花萼、花瓣5基数,花萼呈箭头状,相邻花瓣螺旋轮生,旗瓣较大位于最外边,两片翼瓣紧贴旗瓣着生并包裹两片合生的龙骨瓣,龙骨瓣内包裹着雌、雄蕊,雌蕊位于正中央,雄蕊轮生,构成二体雄蕊(多数9+1,少数5+5)。对蝶形花亚科植物的花部特征、传粉功能群、酬物与传粉系统构建进行了回顾,重点论述了蝶形花形态和化学组成与传粉系统的进化关系以及花粉呈现机制。其中,泛化的传粉系统以蜂媒传粉为主,同时存在鸟媒传粉、蝙蝠传粉和松鼠传粉等方式,花部结构和传粉者的相互选择和相互适应推动了传粉系统的演化。花粉释放是体现蝶形花植物与其传粉功能群相互作用的重要方面,二者协同进化形成了以下4种花粉呈现机制:弹花机制、活塞机制、瓣膜机制和毛刷机制。蝶形花的花部特征与传粉功能群的相互作用形成相应的传粉系统,而传粉系统是执行传粉功能的重要集合体,各个构件的相互协调和适应保证了蝶形花亚科植物传粉过程的顺利完成。

Floral morphology and its relationship with pollination systems in Papilionoideae

The formation of the diverse pollination systems in Papilionoideae is greatly dependent on the relationships between species richness and their functional groups of pollinators. The floral morphology in Papilionoideae plants is complex. The flowers of most taxa of Papilionoideae have a full complement of organs: pentamerous alternating whorls of sepals, petals, two stamen whorls and a single carpel. The floret has a median sagittal sepal, a bigger vexillum on the outside, and two wings close to the vexillum that parcel two keels of contention. The ten stamens are usually united into two groups (mainly 9+1, few 5+5), called diadelphous stamens. In this paper, we reviewed floral syndrome, functional groups of pollinators, rewards and pollination system in Papilionoideae. Particularly, floral morphology and chemical compositions and their relationships with evolution of pollination systems and mechanism of pollen release were discussed. Pollination system in Papilionoideae plants is mainly bee pollination, with avian pollination, squirrel pollination and bat pollination also present. The pollination system is usually an evolutionary outcome of selection and adaptation between floral morphology and pollinators. The mechanism of pollen release is one of the most important characters that exemplify such interactions between Papilionoideae plants and their pollinators. There are four pollen release mechanisms in Papilionoideae, explosive mechanism, piston mechanism, valvular mechanism and brush mechanism. The selection and adaptation between floral syndrome and the functional groups of pollinators established the pollination system, in which the coordination and adaptation among the components are essential for successful pollination.