Global phylogeography of the insect pest Callosobruchus maculatus (Coleoptera: Bruchinae) relates to the history of its main host, Vigna unguiculata
Global phylogeography of the insect pest Callosobruchus maculatus (Coleoptera: Bruchinae) relates to the history of its main host, Vigna unguiculata
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DOI：
10.1111/jbi.13052
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发表时间：
2017-11-01
影响因子：
3.9
通讯作者：
Espindola, Anahi
中科院分区：
文献类型：
--
作者：
Kebe, Khadim;Alvarez, Nadir;Espindola, Anahi
目的：豆象是一种重要的热带、亚热带豆科害虫，分布广泛。考古证据表明，非洲起源与后来的世界范围内的入侵促进了最后几个世纪的豆类贸易和交流。到目前为止，没有任何研究能够确定该物种扩散的路线或时间。在这里，我们调查了这种害虫的全球分布，揭示了主要的洲际传播路线，导致它成为一个世界性的pest.Location：World-wide.Methods：我们采样种子甲虫在很大一部分的物种的范围和测序的一个核和三个线粒体基因座。使用这些数据，我们估计时空的地理重建，和该物种的人口历史。我们还使用我们的数据集来评估的效果panmixia贝叶斯人口estimations.Results：Callosobruchus maculatus表现出区域和大陆的遗传结构，在非洲发现的遗传多样性最高。我们的离散贝叶斯地理方法表明，该物种首先分散到亚洲，然后殖民泛热带带。本文介绍了推断我国南方古猿种群历史的三种方法。maculatus表明，在世界范围内的数据集，以及在子集仅限于非洲样本最近的人口扩张。然而，在由亚洲标本组成的亚组中未观察到此类信号。这种人口扩张发生在全新世，可能是解释的豇豆和其他主机豆科植物的传播和走出Africa.Main conclusions：推断的传播路线支持的想法，C。斑叶豇豆与其主要寄主植物豇豆（Vigna unguiculata）的贸易有关。人类介导的过程似乎塑造了这种害虫的全球遗传结构。作为一种方法的含义，我们表明，合并为基础的人口重建可能是错误的，如果数据集违反了假设的panmixia。
Aim: The seed beetle Callosobruchus maculatus is an important tropical and subtropical pest of legumes distributed world-wide. Archaeological evidence suggests an African origin with later world-wide invasion facilitated by the last centuries' legume trading and exchange. To date, no studies could identify the routes or timing of dispersal of the species. Here, we investigate the global phylogeography of this pest to shed light on the main inter-continental dispersal routes that led to it becoming a cosmopolitan pest.Location: World-wide.Methods: We sampled seed beetles over a large fraction of the species' range and sequenced one nuclear and three mitochondrial loci. Using this data, we estimated spatio-temporal phylogeographical reconstructions, and the demographic history of the species. We also used our dataset to evaluate the effect of panmixia on Bayesian demographic estimations.Results: Callosobruchus maculatus exhibited regional and continental genetic structure, with the highest genetic diversity found in Africa. Our discrete Bayesian phylogeographical approach indicated that the species first dispersed to Asia and then colonized the pantropical belt. The three methods used for inferring the demographic history of C. maculatus indicated a recent demographic expansion in the world-wide dataset, as well as in the subset restricted to African samples. Such a signal was, however, not observed in the subset composed of Asian specimens. This demographic expansion occurred in the Holocene and is likely explained by the spread of cowpea and other host legumes across and out of Africa.Main conclusions: The inferred dispersal routes support the idea that the evolutionary history of C. maculatus relates to the trade of its main host plant, Vigna unguiculata. Human-mediated processes appear to have shaped the global genetic structure of this pest. As a methodological implication, we demonstrate that coalescent-based demographic reconstructions can be erroneous if the dataset violates the assumption of panmixia.