Host specificity of two pollinating seed-consuming fly species is not related to soil moisture of host plant in the high Himalayas.
Host specificity of two pollinating seed-consuming fly species is not related to soil moisture of host plant in the high Himalayas.
复制标题
喜马拉雅山高地两种授粉种子消耗蝇类的寄主特异性与寄主植物的土壤湿度无关
DOI：
10.1002/ece3.2644
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发表时间：
2017-01
影响因子：
2.6
通讯作者：
Sun H
中科院分区：
文献类型：
--
作者：
Song B;Stöcklin J;Gao YQ;Peng DL;Sun H
研究寄主特异性的驱动因素有助于我们理解专性传粉互惠的起源和进化。偏好-表现假说认为，雌性昆虫对寄主植物的选择主要与其后代的表现有关。土壤湿度被认为对栖息在土壤中的幼虫和蛹的生存特别重要。在高喜马拉雅地区，大黄和R. alexandum的分布在土壤水分方面有所不同，即R. nobile通常发生在碎石排水良好的土壤中，R.湿地里的亚历山大这两种植物物种由它们各自的互利共生的种子消耗蝇（Bradysia sp1）授粉。和缓行症sp2。我们调查了土壤湿度是否是重要的调节主机特异性通过比较两种苍蝇的化蛹和成虫出现现场和实验室实验。实验室实验表明，土壤水分确实有显着的影响，幼虫和蛹的性能在这两个苍蝇物种，但这两个苍蝇物种有类似的最佳土壤水分要求化蛹和成虫出现。此外，现场相互转移实验表明，有两个苍蝇物种的本地和非本地栖息地之间的成虫出现没有显着差异。然而，徐缓症sp1.，与R. nobile对干旱胁迫的耐受性较强，而Bradysia sp2.，与R. alexandum对淹水胁迫的耐受性较强。这些结果表明，土壤水分是不可能发挥决定性的作用，在调节寄主特异性的两种苍蝇。然而，它们的化蛹和成虫出现在极端潮湿或干燥的土壤中是生境特异性的。
Studying the drivers of host specificity can contribute to our understanding of the origin and evolution of obligate pollination mutualisms. The preference–performance hypothesis predicts that host plant choice of female insects is related mainly to the performance of their offspring. Soil moisture is thought to be particularly important for the survival of larvae and pupae that inhabit soil. In the high Himalayas, Rheum nobile and R. alexandrae differ in their distribution in terms of soil moisture; that is, R. nobile typically occurs in scree with well‐drained soils, R. alexandrae in wetlands. The two plant species are pollinated by their respective mutualistic seed‐consuming flies, Bradysia sp1. and Bradysia sp2. We investigated whether soil moisture is important for regulating host specificity by comparing pupation and adult emergence of the two fly species using field and laboratory experiments. Laboratory experiments revealed soil moisture did have significant effects on larval and pupal performances in both fly species, but the two fly species had similar optimal soil moisture requirements for pupation and adult emergence. Moreover, a field reciprocal transfer experiment showed that there was no significant difference in adult emergence for both fly species between their native and non‐native habitats. Nevertheless, Bradysia sp1., associated with R. nobile, was more tolerant to drought stress, while Bradysia sp2., associated with R. alexandrae, was more tolerant to flooding stress. These results indicate that soil moisture is unlikely to play a determining role in regulating host specificity of the two fly species. However, their pupation and adult emergence in response to extremely wet or dry soils are habitat‐specific.