通泉草属3种植物柱头触敏性与花部特征之间的关系

选取3种具有不同传粉环境及花部结构差异明显的通泉草属(Mazus)植物,即毛果通泉草(M.spicatus Vaniot)、长蔓通泉草(M.longipes Bonati)和弹刀子菜(M.stachydifolius(Turcz.)Maxim.),观测其柱头触敏性行为,测量有关花部性状,对它们之间的相关性进行比较分析。结果显示,在相同强度的刺激下,毛果通泉草的柱头最为迟钝(闭合时间最长),弹刀子菜最为敏感,而长蔓通泉草介于两者之间。此外,柱头触敏性最强的弹刀子菜比柱头触敏性相对较弱的长蔓通泉草和毛果通泉草具有更深的花色、更大的单花展示、更长的药柱距以及更大的花粉胚珠比。研究结果表明通泉草属植物柱头触敏性的进化与花部特征密切相关,它们共同影响传粉过程中对传粉者的吸引、花粉落置、传递效率以及植物交配系统的构成式样。

Relationship between stigma sensitivity and floral traits in three Mazus (Mazaceae) species with bilobed stigma

Three Mazus species, that is M. spicatus Vaniot, M. longipes Bonati, and M. stachydifolius (Turcz.) Maxim., in different pollination environments and with significantly different floral structures were selected in our study. By observing stigma behaviors and measuring floral traits, the relationships among them were analyzed and compared. Results indicated that under the same stimulation, M. spicatus was the least sensitive (Longest stigma closing time), followed by M. longipes, with M. stachydifolius being the most sensitive. Furthermore, the three Mazus species showed significant differences in floral traits, such as flower color, floral display, anther stigma separation, and pollen-ovule ratio. Compared to M. spicatus and M. longipes with weaker stigma sensitivity, M. stachydifolius with stronger stigma sensitivity had purple flowers, larger single flower display area, longer anther-stigma separation, and larger pollen-ovule ratio. Our study indicates that the evolution of stigma sensitivity in Mazus may be closely linked with floral traits that influence pollinator attraction, pollen loads, pollen deliver efficiency, and composition pattern of the plant mating system.