Islands of water in a sea of dry land: hydrological regime predicts genetic diversity and dispersal in a widespread fish from Australia's arid zone, the golden perch (Macquaria ambigua)
Islands of water in a sea of dry land: hydrological regime predicts genetic diversity and dispersal in a widespread fish from Australia's arid zone, the golden perch (Macquaria ambigua)
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DOI：
10.1111/j.1365-294x.2010.04848.x
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发表时间：
2010-11-01
影响因子：
4.9
通讯作者：
Beheregaray, Luciano B.
中科院分区：
文献类型：
--
作者：
Faulks, Leanne K.;Gilligan, Dean M.;Beheregaray, Luciano B.
河流为研究生物多样性结构格局和生态过程之间的相互作用提供了一个很好的系统。在这些环境中，基因流动受到排水网络内连通性的空间等级和时间变化的限制。在澳大利亚干旱地区，这种变化性很高，河流经常作为孤立的水洞存在，在不可预测的洪水期间连接在一起。这些条件导致了类群种群动态的繁荣/萧条周期，但它们对空间遗传多样性的影响在很大程度上是未知的。我们使用景观遗传学方法评估了水文变异性对澳大利亚淡水鱼Macquaria ambiua的基因流、空间种群结构和遗传多样性的影响。我们的分析基于来自26个物种范围内26个地点的590个样本的微卫星数据。尽管种群在时间上是孤立的，但该物种表现出惊人的高分散率，种群遗传结构仅在主要流域才明显。在流域内，水文变异性是遗传多样性的有力预测因子，与春季流量呈正相关。我们认为，春季流量的增加刺激了招聘的繁荣和扩散，提高了种群规模和遗传多样性。虽然还不确定干旱的澳大利亚的水文状况在未来气候情景下可能如何变化，但干旱地区鱼类的管理战略应该减少扩散障碍和自然水流状况的改变，以维持连通性和物种的进化潜力。这项研究有助于我们理解时空异质性对人口和景观过程的影响。
Rivers provide an excellent system to study interactions between patterns of biodiversity structure and ecological processes. In these environments, gene flow is restricted by the spatial hierarchy and temporal variation of connectivity within the drainage network. In the Australian arid zone, this variability is high and rivers often exist as isolated waterholes connected during unpredictable floods. These conditions cause boom/bust cycles in the population dynamics of taxa, but their influence on spatial genetic diversity is largely unknown. We used a landscape genetics approach to assess the effect of hydrological variability on gene flow, spatial population structure and genetic diversity in an Australian freshwater fish, Macquaria ambigua. Our analysis is based on microsatellite data of 590 samples from 26 locations across the species range. Despite temporal isolation of populations, the species showed surprisingly high rates of dispersal, with population genetic structure only evident among major drainage basins. Within drainages, hydrological variability was a strong predictor of genetic diversity, being positively correlated with spring-time flow volume. We propose that increases in flow volume during spring stimulate recruitment booms and dispersal, boosting population size and genetic diversity. Although it is uncertain how the hydrological regime in arid Australia may change under future climate scenarios, management strategies for arid-zone fishes should mitigate barriers to dispersal and alterations to the natural flow regime to maintain connectivity and the species' evolutionary potential. This study contributes to our understanding of the influence of spatial and temporal heterogeneity on population and landscape processes.