Key Laboratory of Biodiversity and Biogeography and Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650204, China.
Proc Natl Acad Sci U S A. 2011 May 3;108(18):7478-80. doi: 10.1073/pnas.1103384108. Epub 2011 Apr 18.
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.
查尔斯·达尔文对兰花-传粉者相互作用很着迷，但他没有意识到许多兰花物种是通过欺骗来传粉的。杓兰，一个不回报的兰花花系模式，主要由蜜蜂授粉。在这里，我们展示了一个兰花模拟真菌感染叶子的例子，以及一个扁平脚蝇（Agathomyia sp.；Platypezidae）作为被子植物花粉载体的例子。杓兰（Cypripedium fargesii）是一种来自中国西南部的无蜜、陆生、濒危兰花，需要异花授粉才能产生最大数量的可育胚胎。所有进入或离开唇瓣囊的昆虫都是携带黑盘孢属分生孢子的扁平脚蝇（Agathomyia sp.），这表明它们是食真菌的。叶子上表面的黑色多毛斑点可能模仿黑霉菌斑点，作为短期视觉诱饵。在花香中还分离出了一些与黑盘孢属培养物相关的气味分子。真菌感染叶子的拟态可能代表了被子植物多样化中一个被忽视但重要的选择，因为在中国西南部还有三到五种杓兰属植物具有相同的花部展示和带黑斑的多毛叶子。
