Invasive Species Compendium

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Abstract

The effects of pollination disturbance on the endemic plant species Leptopetalum grayi (Rubiaceae) in the Ogasawara Islands, Japan.

Abstract

In the Ogasawara Islands, Japan, the invasion of alien species, such as the green anole and honeybee, has affected the pollination of native plant communities. Although these disturbances are predicted to have negative effects on the genetic diversity and reproductive success of native plant species in the Ogasawara Islands, the effects on genetic characters are still unclear. This study compared the pollinator fauna and reproductive success of Leptopetalum grayi (Rubiaceae) on Chichijima and Mukojima, in the Ogasawara Islands. On Mukojima, many native pollinators have survived because there are no invasive alien species. We also compared the genetic diversity of adult plants and their seeds using 14 microsatellite markers. There were fewer native flower visitors on Chichijima than on Mukojima. The fruit set rate was also significantly lower than on Mukojima (P<0.05). These findings indicate that the pollination disturbance on Chichijima has had negative effects on reproductive success. Nevertheless, there were no significant differences in the genetic diversity of adult plants or seeds on both islands. This implies that genetic diversity has not yet been affected by the disturbed pollination on Chichijima.