Floral fragrances in two closely related fruit fly orchids, Bulbophyllum hortorum and B. macranthoides (Orchidaceae): assortments of phenylbutanoids to attract tephritid fruit fly males
- 26 Downloads
Floral chemical components are important cues used by plants to attract pollinators. One outstanding case is “fruit fly orchids” in the genus of Bulbophyllum to attract their pollinators by releasing characteristic fragrances. Dacini fruit flies are main or exclusive pollinators which are strongly attracted to certain natural chemicals, either methyl eugenol (ME: a phenylpropanoid) or raspberry ketone (RK: a phenylbutanoid). Furthermore, zingerone (ZN: a phenylbutanoid) has been characterized as the attractant for both ME- and RK-sensitive fruit fly species. In the present study, we examined chemical profiles of two closely related Bulbophyllum orchids—B. hortorum, and B. macranthoides subsp. tollenoniferum—distributed in Papua New Guinea and the Southeast Asian countries, respectively. We first observed that RK-sensitive flies were attracted to these orchids by ex situ cultivation in Penang, Malaysia. These Bulbophyllum orchids contained RK and/or ZN as their main floral components. Other than these attractants, multiple phenylbutanoids including potential attractants for RK-sensitive species were identified from these orchids. Therefore, we examined attractiveness of potential phenylbutanoid attractants to an RK-sensitive melon fly, Zeugodacus cucurbitae, using laboratory-reared flies. Furthermore, we analyzed molecular phylogenetic relationships among phenylpropanoid- or phenylbutanoid-producing orchids to see a relation between chemical profiles and phylogenetic classification in the related species.
KeywordsBulbophyllum Floral volatiles Phenylbutanoids Pollination Dacini fruit flies
We thank Jaap J. Vermeulen for confirmation of the species and subspecies of the Bulbophyllum species; and Jane Royer for the Dacus species identification. We thank Atsushi Honma and Yasutsune Sadoyama of Okinawa Prefectural Plant Protection Center for providing Z. cucurbitae. We also thank Ayako Sasaki for technical assistance. R. Nishida was partly supported by the Grant-in-Aid for Scientific Research from JSPS (Nos. 19310142 and 23380035) from the Ministry of Education, Culture, Sports, Science and Technology of Japan. H. Ono was partly supported by JSPS KAKENHI Grant Number 26450466.
- Koeduka T, Watanabe B, Suzuki S, Hiratake J, Mano J, Yazaki K (2011) Characterization of raspberry ketone/zingerone synthase, catalyzing the alpha, beta-hydrogenation of phenylbutenones in raspberry fruits. Biochem Biophys Res Commun 412:104–108. https://doi.org/10.1016/j.bbrc.2011.07.052 CrossRefPubMedGoogle Scholar
- Kuo P, Damu AG, Cherng CY, Jeng JF, Teng CM, Lee EJ, Wu TS (2005) Isolation of a natural antioxidant, dehydrozingerone from Zingiber officinale and synthesis of its analogues for recognition of effective antioxidant and antityrosinase agents. Arch Pharm Res 28:518–528. https://doi.org/10.1007/BF02977752 CrossRefPubMedGoogle Scholar
- Nishida R, Tan KH (2016) Search for new fruit fly attractants from plants: A review. In: Sabater-Munoz B, Vera T, Pereira R, Orankanok W (eds) Proceedings of the 9th International Symposium on Fruit Flies of Economic Importance, Bangkok, Thailand, pp 249–262Google Scholar
- Ong PT (2013) The pollination of two Bulbophyllum species. Orchid Review 2013 September Issue:152–155Google Scholar
- Tan KH, Nishida R, Jang EB, Shelly TE (2014) Pheromones, male lures, and trapping of tephritid fruit flies. In: Shelly T, Epsky N, Jang EB, Reyes-Flores, Vargas R (eds) Trapping and the detection, control, and regulation of tephritid fruit flies. Springer, Dordrecht, pp 15–74. https://doi.org/10.1007/978-94-017-9193-9 CrossRefGoogle Scholar