Mant Jim G, Schiestl Florian P, Peakall Rod, Weston Peter H
School of Botany and Zoology, Australian National University, Canberra, Australian Capital Territory.
Evolution. 2002 May;56(5):888-98. doi: 10.1111/j.0014-3820.2002.tb01402.x.
Orchids of the genus Chiloglottis are pollinated through the sexual deception of male wasps mainly from the genus Neozeleboria (Tiphiidae: Thynninae). The orchids mimic both the appearance and sex pheromones of wingless female thynnines but provide no reward to the deceived males. Despite the asymmetry of this interaction, strong pollinator specificity is typical. Such plant-pollinator interactions would seem to be relatively flexible in the plant's adaptive response to variation in the local pollinator resource. However, we present DNA sequence data on both orchids and wasps that demonstrate a pattern of pollinator conservatism operating at a range of taxonomic levels. Sequence data from the wasps indicate 15 of 16 Chiloglottis pollinators are closely related members of one clade of Thynninae. A pattern of congruence between orchid and wasp phylogenies is also demonstrated below the generic level, such that related orchids tend to use related thynnine wasps as specific pollinators. Comparative physiological data on the wasp responses to the floral scents of two Chiloglottis species and one outgroup, Arthrochilus, indicate similar attractive volatile chemicals are used by related orchid taxa. By extension, we infer a similarity of sex pheromone signals among related thynnines. Thus, the conservative pattern of pollinator change in sexually deceptive orchids may reflect phylogenetic patterns in the sex pheromones of their pollinators.
舌唇兰属的兰花主要通过对新泽蜂属（姬蜂科：瘦蜂亚科）雄性黄蜂的性欺骗来实现授粉。这些兰花模仿无翅瘦蜂雌性的外观和性信息素，但不会给受骗的雄性黄蜂提供任何回报。尽管这种相互作用存在不对称性，但授粉者的高度特异性却是常见的。这种植物与授粉者之间的相互作用在植物对当地授粉者资源变化的适应性反应中似乎相对灵活。然而，我们展示了关于兰花和黄蜂的DNA序列数据，这些数据表明授粉者保守模式在一系列分类水平上都存在。黄蜂的序列数据显示，16种舌唇兰授粉者中有15种是瘦蜂亚科一个分支中的密切相关成员。在属以下水平也显示出兰花和黄蜂系统发育之间的一致性模式，即相关的兰花倾向于使用相关的瘦蜂黄蜂作为特定授粉者。关于黄蜂对两种舌唇兰物种和一个外类群——无柱兰属植物花香反应的比较生理学数据表明，相关的兰花类群使用相似的有吸引力的挥发性化学物质。由此推断，我们认为相关瘦蜂之间的性信息素信号具有相似性。因此，性欺骗兰花授粉者变化的保守模式可能反映了其授粉者性信息素中的系统发育模式。
