Origin and evolution of obligate pollination mutualism and pollination commensalism

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We observed pollination biology of many species of Glochidion and related genera of Phyllanthaceae (Breynia, Phyllanthus, Saurops, Margaritaria and Flueggea). In Ryukyu Islands, we made night observation on pollination of 5 Glochidion species, and found that all these species were actively pollinated by small moths of Epicephala (Gracillariidae). To detect selfincmpatibility and outcrossing rate, we made bagging experimens. We also collected odors emitted from flowers, and analyzed compounds of the odors by using gas chromatography and mass spectrometry. The composition of the odor blends differed among the studied Glochidion species. Precise investigations on plant-pollinator interactions in the Ryukyu Archipelago suggested that host specificity rarely collapsed by coexistence of two cryptic species of pollinating moths.We made pollination systems of various species of Phyllanthaceae in New Caledonia, Laos, Madagascar and Cuba, and found that the obligate pollination mutualism is found throughout the wide ranges of the tropical and subtropical regions. We analyzed molecular phylogenies of Phyllanthaceae and its pollination partners, Epicephala moths. The comparison of the phylogenies detected that their phylogenies are largely parallel, but that host change has occurred at least several times in the past.We also observed Rheophytic herbaceous plants, Mitella (Saxifragaceae), and detected that almost all species except one were pollinated by mycetophilid midges. Molecular phylogenies of Mitella and related genera suggested that mycetophily has evolved several times in North America and Japan. The plant-pollinator interaction may be an example of pollinator commensalism.