中科院西雙版納植物園博士研究生陳春在導(dǎo)師宋啟示的指導(dǎo)下,，與法國有關(guān)研究人員合作,，通過分析榕樹隱頭花序揮發(fā)物和檢測榕小蜂對揮發(fā)物的行為反應(yīng)，發(fā)現(xiàn)了罕見的榕樹通過釋放單一的不常見揮發(fā)性化合物,，達(dá)到對其傳粉榕小蜂的專性吸引,，以確立榕樹與榕小蜂間專一性的共生關(guān)系。
該項研究發(fā)現(xiàn)4-甲基苯甲醚在雌雄異株的雞嗉子榕Ficus semicordata的開放期隱頭花序揮發(fā)物中占主導(dǎo)地位（94-98%）,，并在隱頭花序授粉或寄生4天后完全消失,，且不存在于其它榕樹的花序揮發(fā)物中。生物檢測發(fā)現(xiàn)4-甲基苯甲醚對雞嗉子榕小蜂Ceratosolen gravelyi有吸引作用,，而不含對甲基苯甲醚的其它榕樹的花序揮發(fā)物則無此吸引作用,。
研究結(jié)果表明4-甲基苯甲醚，一種不常見的榕樹揮發(fā)性化合物,，確定了對雞嗉子榕傳粉者的專一性吸引,，建立了一種獨特的榕樹/榕小蜂專一性共生關(guān)系。該項研究結(jié)果已在權(quán)威生態(tài)學(xué)雜志FUNCTIONAL ECOLOGY網(wǎng)上發(fā)表,。
榕樹與榕小蜂間形成了生物界典型的專一性共生關(guān)系,，一種榕樹僅僅依賴于一種榕小蜂為其傳粉，相應(yīng)地,，榕小蜂也只仰仗一種榕樹為其提供繁殖后代的場所和食物,。以前的研究表明榕樹隱頭花序的氣味在榕樹與榕小蜂間共生中起重要作用。（生物谷Bioon.com）
生物谷推薦原始出處：
Functional Ecology 5 Aug 2009 DOI:10.1111/j.1365-2435.2009.01622.x
Private channel: a single unusual compound assures specific pollinator attraction in Ficus semicordata
Chun Chen 1,? , Qishi Song 1,? , Magali Proffit 2,4 , Jean-Marie Bessière 3 , Zongbo Li 1 and Martine Hossaert-McKey*,2
1 Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China ; 2 Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR CNRS, Montpellier Cedex, France ; 3 Laboratoire de Chimie Appliquée, Ecole Nationale Supérieure de Chimie de Montpellier, Montpellier Cedex, France ; and 4 School of Biological and Conservation Sciences, University of KwaZulu-Natal, Scottsville, Pietermaritzburg, South Africa
1. Floral scents have been suggested to play a key role in the obligate pollination mutualism between figs and fig wasps. However, few studies have determined whether pollinator-attractive compounds could alone assure species-specificity ('private channel'), or whether specificity is mediated by more complex 'floral filters', of which scent is only one component.
2. We examined changes in the floral volatile compounds of Ficus semicordata, a dioecious fig species, during and after pollination using headspace collection and compound identification by Gas Chromatography/Mass Spectrometry (GC/MS). One benzenoid compound, 4-methylanisole, was strongly predominant (94–98%) among the volatile compounds emitted by both male and female receptive figs of F. semicordata, whereas it was totally absent in the volatiles emitted by figs 4 days after pollination, as well as in receptive-stage volatiles emitted by two other sympatric fig species, Ficus racemosa and Ficus hispida.
3. Bioassays using the specific pollinator of F. semicordata, Ceratosolen gravelyi, in a Y-tube olfactometer showed that 4-methylanisole was attractive to C. gravelyi in a wide range of concentrations (from 1·22 × 10?2 ng/100 μL to 1·22 × 106ng/100μL). Moreover, chemical blends lacking 4-methylanisole were unattractive to C. gravelyi. These non-active odour sources included volatile compounds emitted by receptive figs of the two other sympatric fig species and volatiles of F. semicordata post-pollination figs.
4. All these results suggest that 4-methylanisole is the main signal compound in the floral scent of F. semicordata that attracts its obligate pollinator to the host figs at the precise stage required for pollination and oviposition. Furthermore, the high proportion of 4-methylanisole in the odours of receptive figs of both sexes was consistent with the hypothesis of chemical mimicry in dioecious figs.
5. A simple signal comprised of one compound that is unusual among Ficus and that is an infrequent, usually minor, component of other floral odours, may thus function as a private channel in this specialized obligate mutualism.
