珍稀濒危植物单性木兰传粉生态学研究

Pollination ecology of rare and endangered species Kmeria septentrionalis

野外定位观测了单性木兰的花期物候、访花昆虫种类、访花频率、访花行为和同花期植物种类,并对其花粉散播距离和繁育系统进行了检测,旨在探讨制约单性木兰传粉过程的某些因素,为单性木兰的保护生物学提供科学依据。结果表明,单性木兰雄株和雌株在花期物候上存在差异,雌株在结实上存在明显的大小年现象。单性木兰以虫媒传粉为主,雄株访花昆虫30种,雌株访花昆虫仅14种,雌株和雄株共有的访花昆虫仅6种。单性木兰同花期植物共17种,其访花昆虫种类大部分与单性木兰的访花昆虫种类相同。蜂类和蝶类均非单性木兰的传粉者,其结实率低的原因不仅与访花昆虫种类少和访花频率少有关,更与其缺乏有效的传粉昆虫有关。

The flowering phenology,species of visiting insects, visitation rate of pollinators and their foraging behavior,and plant species at the same flowering time of Kmeria septentrionalis were investigated in Mulun National Nature Reserve in Guangxi, and the breeding system and spreading distance of pollens of it were determined. The results were as follows：there was difference in flowering phenology for male plants and female plants,and unstable yielding phenomenon in fruiting characteristics was existed for female plants. Insects pollination was the main pollination media of K. septentrionalis,the number of foraging insect species for male plants is 30,the number for female plants is only 14,the common foraging insect species is only 6. There are 17 plant species at the same flowering time ,and most of foraging insect species of them are the same as that of K. septentrionalis. Bees and butterfly species are not pollinators. The reasons for low fruit set are not only related to small number of foraging insect species and low visitation rate of pollinators, but also related to the lack of effective pollinators.