The bracts of the alpine 'glasshouse' plant Rheum alexandrae (Polygonaceae) enhance reproductive fitness of its pollinating seed-consuming mutualist
The bracts of the alpine 'glasshouse' plant Rheum alexandrae (Polygonaceae) enhance reproductive fitness of its pollinating seed-consuming mutualist
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DOI：
10.1111/boj.12312
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发表时间：
2015-10-01
影响因子：
2.4
通讯作者：
Sun, Hang
中科院分区：
文献类型：
--
作者：
Song, Bo;Stoecklin, Juerg;Sun, Hang
众所周知，环境条件会影响昆虫的生殖适合度，宿主植物也是如此。虽然喜马拉雅“温室”植物的高度特化的苞片被认为是一种适应性形态，使植物能够在恶劣的高山环境中繁殖，但关于这些苞片对传粉昆虫的益处的信息似乎很少。在这项研究中，我们研究了半透明的苞叶大黄，一个巨大的草本植物特有的中国西南部横断山脉的高山地带，提高其传粉者的生殖适合度。亚历山大大黄主要依赖于共生的种子消耗Bradysia苍蝇授粉。苞片增加室内温度在晴天，作为一个缓冲对波动的空气湿度，大大降低了紫外线B/C辐射的强度，并提供庇护强风。在开花期和结果期，去除苞片显著降低了传粉昆虫的成虫产卵量和后代表现。结果表明，R.在高山环境中，亚历山大草的苞片能提高传粉种子互惠共生体的生殖适合度，这可能是由于苞片对内部微环境的积极影响。(C)2015年伦敦林奈学会。
Environmental conditions are known to affect the reproductive fitness of insects, as do host plants. Although the highly specialized bracts of Himalayan 'glasshouse' plants are thought to be an adaptive morphology that allows the plant to reproduce in harsh alpine environments, little information appears to exist concerning the benefit of these bracts for the pollinating insects. In this study, we examine whether the semi-translucent bracts of Rheum alexandrae, a giant herb endemic to the alpine zone of the Hengduan Mountains in south-western China, enhance the reproductive fitness of its pollinator. Rheum alexandrae depends mainly on mutualistic seed-consuming Bradysia flies for pollination. Bracts increased interior temperature on sunny days, acted as a buffer against fluctuating air humidity, greatly decreased the intensities of ultraviolet B/C radiation and provided shelter from strong winds. Bract removal significantly decreased adult oviposition and offspring performance of pollinators during flowering and fruiting, respectively. Our results indicate that the bracts of R. alexandrae enhance the reproductive fitness of its pollinating seed-consuming mutualist in alpine environments, which may be attributed to the positive effects of the bracts on the interior microenvironment. (C) 2015 The Linnean Society of London.