中国特有的两种同域分布凤仙花属植物的传粉生物学研究 postprint

Abstract: The genus Impatiens exhibits some varied floral features with a dichogamous reproductive system, in which pollination biology plays a key role in speciation and adaptive evolution. China is one of the centers of Impatiens species, comprising over 300 species including a large number of endemic and sympatric distributions, but there are few data on their pollination biology. Comparative pollination biology of two Chinese endemic and sympatric species, Impatiens corchorifolia and I. polyceras, were investigated, including flowering phenology, floral features, flower visitors, behavior of pollinators, and as well as breeding systems. It was turned out as below. (1) Morphology of spur was varied in two species, which played a key role in different floral syndromes. The spurs in I. corchorifolia and I. polyceras could produced a similar nectar sugar content, (45.48 ± 2.28) % and (46.12 ± 1.48) % respectively. They could shared two pollinators, Apis cerana and Vespa. However, the short spur in I. corchorifolia produced less amount of (4.57 ± 1.43) μL nectar while the long spur in I. polyceras yielded more nectar content of (10.15 ± 3.28) μL. And then, the latter also could be pollinate by the other insects including one species of Macroglossum and two species of Bombus. (2) The behavior of the common pollinators shared in I. corchorifolia and I. polyceras were obviously distinguished by their staggered flower visits and differential sizes of flower channels for visitors with inconsistent positions of pollens carried. (3) Both species were dependent on pollinators to set fruits, which were self-incompatible, as well as cross-incompatible between two sympatric species. The results provide new data for better understanding of floral syndrome and speciation of the large genus of Impatiens.