木瓜榕隐头果传粉前后挥发性化合物构成及其变化规律

Components and spatial variations in the emission of volatiles by figs of Ficus auriculata before and after pollination

榕树与其传粉榕小蜂通常以隐头果挥发物作为交流媒介.采用顶空动态法提取木瓜榕隐头果传粉前后的挥发物,用GC-MS联用仪鉴定各化合物,峰面积归一法和内标法测定各成分含量.结果表明:木瓜榕传粉前(雌花期)和传粉后的顶空样品中分离出53种化合物,多数为单萜类和倍半萜类化合物,(E)-β-ocimene、linalool、limonene、5-epiprezizaene、khusimene、cis-β-Cedrene、cis-α-bergamotene、α-farnesene和bicycloger-macrene是其重要的挥发物成分.雌花期隐头果挥发物释放量明显高于传粉后挥发物释放量,且雌雄隐头果挥发物种类、构成及释放量上高度类似,存在着明显的模拟现象.同时,雌雄个体挥发物释放量存在明显的空间变异.

Fig volatiles are important medium for chemical communication between figs and fig wasps. Vola- tile compounds were obtained by the dynamic headspace techniques from the figs of F. auriculata before and af- ter pollination. The chemical components were identified by GC - MS method, and the content of each component was determined by the area normalization and internal standard method, receptively. Fifty -three different volatile organic compounds, predominantly monoterpenes and sesquiterpenes, were identified in the receptivity and the postpolliantion. （E） - β - ocimene, linalool, limonene, 5 - epiprezizaene, khusimene, c/s - β - cedrene, α - far- nesene and bicyclogermaerene were considered as major candidate for biological activity. The quantity was signifi- cantly higher before the pollination than after the pollination. There was obviously mimicry in the volatile quanti- ty, category and constituent for the female figs and male figs. Furthermore, spatial variation of volatile quantity was also found in female figs and male figs. The results provided new insights to understand the stability and chemical maintenance in the obligate fig- wasp mutualism.