要旨
Fig (Ficus syconia) - associated nematodes are diverse, with several different groups of nematodes including dip- logastrids (Parasitodiplogaster, Teratodiplogaster, Mononchoides and some other undescribed genera), tylenchids (Ficotylus) and aphelenchoidids (Schistonchus) having been isolated from various subgroups of Ficus trees. Most of the fig-associated nematode studies have been conducted in North and Central America, Australia, Africa, and South Asia, yet knowledge of these nematodes in East Asia has been scarce. We conducted a preliminary survey of these nematodes in East Asian subtropical areas, i.e. from three fig species, Ficus variegata, F. septica, and F. auriculata in Japan, Taiwan, and Vietnam, respectively. F. variegata and F. septica were collected from Ishigaki and Iriomote Islands, Okinawa, Japan and from Orchid Island and the southern part of the main island of Taiwan. Specimens of F. auriculata were collected from Cuc Phuong National Park, Ninh Binh Province, Vietnam. Figs (B-C phases) were collected, brought back to the laboratory, and dissected under a stereomicroscope. Isolated nematodes were fixed in TAF for morphological comparisons or in DESS for combined morphological and molecular analyses. Some of the recovered nematodes were observed under a compound microscope prior to placement in nematode digestion buffer for molecular protocols. Although detailed molecular sequence analyses are still incomplete, several different morphotypes of nematodes were recorded from the examined fig species. An undescribed Teratodiplogaster sp. and two morphotypes of Schistonchus spp. were isolated from F. variegata and an unidentified rhabditid species and two morphotypes of Schistonchus were recovered from F. septica. These nematode species (morphotypes) were isolated from all four islands examined. Ficus auriculata did not harbor Teratodiplogaster, which is associated with other Sycomorus-group fig species, but at least two morphotypes of undescribed diplogastrids and a Schistonchus sp. were isolated from this fig species. Of these undescribed diplogastrids, one is morphologically similar to a species isolated from African figs. More surveys of fig-associated nematodes in the African and Asian tropics are necessary to elucidate the evolutionary history and diversity of fig-fig wasp-nematode associations.
