Flowers of Cypripedium fargesii (Orchidaceae) fool flat-footed flies (Platypezidae) by faking fungus-infected foliage
Flowers of Cypripedium fargesii (Orchidaceae) fool flat-footed flies (Platypezidae) by faking fungus-infected foliage
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DOI：
10.1073/pnas.1103384108
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发表时间：
2011-05-03
影响因子：
11.1
通讯作者：
Wang, Hong
中科院分区：
文献类型：
--
作者：
Ren, Zong-Xin;Li, De-Zhu;Wang, Hong
查尔斯·达尔文着迷于兰花与传粉者的相互作用，但他没有意识到许多兰花物种是通过欺骗来授粉的。塞浦路斯，一种典型的无回报的兰花，主要由蜜蜂授粉。在这里，我们提出了兰花真菌感染叶片的花卉模仿的例子和扁足蝇（Agathomyia sp.；扁桃科）作为被子植物花粉载体的例子。锦绣兰是一种无花蜜的陆生濒危兰花，来自中国西南部，需要异花授粉才能产生最多数量的可存活胚胎。所有进入或离开唇囊的昆虫均为Agathomyia sp.，其口器和腿上携带枝孢孢子，提示有真菌吞噬。叶片上表面的黑色毛斑可能模仿黑霉斑，作为短期的视觉诱饵。一些与枝孢菌培养相关的气味分子也从花香中分离出来。真菌感染叶片的模仿可能代表了被子植物多样化中一个被忽视但重要的选择，因为在中国西南部有3到5种以上的塞浦路斯属植物，它们具有相同的花呈现模式和黑色斑点的毛茸茸的叶子。
Charles Darwin was fascinated by the orchid-pollinator interactions, but he did not realize that many orchid species are pollinated by deceit. Cypripedium, a model lineage of nonrewarding orchid flowers, is pollinated primarily by bees. Here we present both an example of floral mimesis of fungus-infected foliage in orchids and an example of flat-footed flies (Agathomyia sp.; Platypezidae) as pollen vectors for angiosperms. Cypripedium fargesii is a nectarless, terrestrial, endangered orchid from southwestern China that requires cross-pollination to produce the maximum number of viable embryos. All insects caught entering or leaving the labellum sac were Agathomyia sp. carrying conidia of Cladosporium sp. on their mouthparts and legs, suggesting mycophagy. Blackish hairy spots on the upper surface of foliage may imitate black mold spots, serving as short-term visual lures. Some odor molecules also associated with Cladosporium cultures were isolated in the floral scent. Mimesis of fungus-infected foliage probably represents an overlooked but important option in angiosperm diversification, because there are three to five more Cypripedium spp. in southwestern China with the same mode of floral presentation and black-spotted hairy leaves.