Temporal and sexual variation of leaf-produced pollinator-attracting odours in the dwarf palm
Temporal and sexual variation of leaf-produced pollinator-attracting odours in the dwarf palm
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DOI：
10.1007/s00442-004-1538-y
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发表时间：
2004-05-01
期刊：
影响因子：
2.7
通讯作者：
Anstett, MC
中科院分区：
文献类型：
--
作者：
Dufa, M;Hossaert-McKey, M;Anstett, MC
关于吸引传粉者的花性状种内变异的信息为传粉者施加的选择压力提供了线索。然而，这些性状也反映了与花物候或形态有关的限制。地中海矮棕榈雌雄异株Chamaerops humilis的特定象鼻虫传粉者Derelomus chamaeropsis被花期叶子释放的挥发性化合物所吸引，而不是花。因此，这些嗅觉线索的产生可能不受任何其他花卉功能的限制。这为研究不是由花器官产生的“花”性状的变异提供了机会。我们研究了12株黄菖蒲在整个花期叶片释放的挥发性化合物。当植物需要传粉者访问时，叶片释放的挥发性化合物的数量达到最大值。雄性和雌性植物的气味释放与花物候的关系略有不同，这可能反映了雌性和雄性从传粉者访问中受益的确切时间的差异。雄性植株比雌性植株产生更多的挥发性化合物。气味组成在个体之间变化很大，但在雌雄植株之间没有差异。在该系统中，黄菖蒲雌蜂采用欺骗传粉方式，授粉者应选择不接近的传粉者。因此，混合成分中性别差异的缺失可能会阻止传粉者区分雌雄植物。
Information on intra-specific variation in pollinator-attracting floral traits provides clues to selective pressures imposed by pollinators. However, these traits also reflect constraints related to floral phenology or morphology. The specific weevil pollinator Derelomus chamaeropsis of the dioecious Mediterranean dwarf palm Chamaerops humilis is attracted by volatile compounds that leaves, and not flowers, release during anthesis. Production of these olfactory cues is thus probably not constrained by any other floral function. This provides the opportunity to study variation of a "floral" trait that is not produced by a floral organ. We studied volatile compounds emitted by leaves of 12 individual C. humilis over the whole flowering season. The quantity of volatile compounds emitted by leaves reached a maximum when plants required pollinator visits. The relationship between odour emission and floral phenology was slightly different between male and female plants, probably reflecting differences in the exact time at which females and males benefit from pollinator visitation. Male plants produced higher quantities of volatile compounds than females. Odour composition was highly variable among individuals but did not differ between male and female plants. In this system, female C. humilis are pollinated by deceit and pollinators should be selected to avoid visiting them. The absence of sexual difference in blend composition may thus prevent pollinators from discriminating between male and female plants.