植物生态学报 ›› 2017, Vol. 41 ›› Issue (5): 549-558.doi: 10.17521/cjpe.2016.0250

• 研究论文 • 上一篇    下一篇

榕树隐头花序挥发物组成及其传粉榕小蜂寄主识别行为

张亭1,2, 王波1, 苗白鸽1, 彭艳琼1,,A;*   

  1. 1中国科学院西双版纳热带植物园热带森林生态学重点实验室, 云南勐腊 666303
    2中国科学院大学, 北京 100049
  • 出版日期:2017-05-10 发布日期:2017-06-22
  • 通讯作者: 彭艳琼
  • 基金资助:
    国家自然科学基金(31300318、31570418和31600302)和云南省应用基础研究计划项目(2016FA0069)

Chemical composition of volatiles from the syconia of Ficus microcarpa and host recognition behavior of pollinating fig wasps

Ting ZHANG1,2, Bo WANG1, Bai-Ge MIAO1, Yan-Qiong PENG1,*   

  1. 1Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Online:2017-05-10 Published:2017-06-22
  • Contact: Yan-Qiong PENG

摘要:

榕树(Ficus spp.)通过挥发性化学物质来吸引传粉榕小蜂(Agaonidae), 这种特异性的化学信号释放存在着两种模式, 一种是释放多种化合物的“泛化”模式, 另一种是释放不常见单一化合物的“专化”模式。为揭示榕树(Ficus microcarpa)及其传粉榕小蜂Eupristina verticillata之间的化学通讯机制, 该研究采用固相微萃取法提取榕树隐头花序不同发育期(花前期、雌花期传粉前后、间花期、雄花期和花后期)释放的挥发物, 并用气相色谱-质谱联用仪鉴定挥发物成分, 分析其变化动态, 再通过Y型嗅觉仪检测榕树传粉榕小蜂对各发育期隐头花序的行为反应。结果表明: 榕树隐头花序释放的挥发性化合物共鉴定出21种, 主要是脂肪酸衍生物、萜类化合物和芳香族化合物。不同发育期隐头花序的挥发物组分差异明显, 雌花期传粉前后的挥发物差异表现为传粉后萜类化合物含量下降, 脂肪酸衍生物含量增加, 特别是传粉前含量较高的特征化合物2-庚酮和3-辛酮消失, D-柠檬烯含量下降, 而可巴烯、环己烷和2-己烯醛含量上升。行为检测的结果也表明: 雌花期隐头花序对传粉榕小蜂的吸引作用最强, 而雄花期的隐头花序释放的挥发物对传粉榕小蜂有趋避作用, 形成了对传粉榕小蜂“推拉”的互作模式。有多种化合物在榕树传粉榕小蜂的寄主识别过程中发挥作用, 表明榕树及其传粉榕小蜂的互惠共生关系是通过多种化合物的“泛化”策略来维系的。

关键词: 榕树, 传粉榕小蜂, 化学通讯, 隐头花序, 挥发物

Abstract:
Aims Chemical communication plays a key role in host plant recognition of pollinators. There are two recognized types of chemical communication between syconia and their pollinating fig wasps: one is “generalization”, of which the wasps respond to the relative ratio of multiple compounds, and the other is “specialization”, of which the key signal is a single uncommon, possibly unique, compound. The aims of this study were to identify the chemical composition of volatiles from the syconia of Ficus microcarpa at different developmental phases, and to determine if the signaling between F. microcarpa and its pollinating fig wasp, Eupristina verticillata, is of generalized type, or of specialized type.Methods The volatiles from syconia of F. microcarpa were extracted using solid-phase micro extraction (SPME) at different developmental phases (pre-female, female (before and after pollination), interfloral, male and postfloral phases) and the chemical compounds were identified by gas chromatography mass spectrometry (GC-MS). We then tested the behavioral responses of E. verticillata to fresh syconia at different developmental phases using two-choice olfactometers.Important findings There were 21 volatile compounds identified from the syconia at different developmental phases, which were mainly fatty acid derivatives, terpenoids and aromatic compounds. The components of the volatiles apparently differed among the developmental stages. The contents of terpenoids declined, but the contents of fatty acid derivatives increased, from before the pollination to after the pollination. Especially, the characteristic compounds of 2-heptanone and 3-octanone before the pollination disappeared, D-limonene decreased after the pollination, but copanene, cyclohexane and 2-hexenal increased. The results of the two-choice olfactometer experiment showed that the pollinating fig wasps had higher selection ratio to chemicals found in the female phase syconia than those in other phases; whereas the volatile compounds from the male phase syconia had the function pushing the pollinating fig wasps to leave the natal syconia so that there existed the “push-pull” responses by fig wasps to volatiles released by their host syconia. We conclude that there are multiple chemical compounds playing the roles in host recognition of pollinating fig wasp E. verticillata. The mutualistic relationship between F. microcarpa and E. verticillata is maintained by the chemical communication of “generalization” strategy.

Key words: Ficus microcarpa, pollinating fig wasps, chemical communication, syconia, volatiles