Daphnia galeata and D. dentifera are geographically and ecologically separated whereas their hybrids occur in intermediate habitats: A survey of 44 Chinese lakes
Daphnia galeata and D. dentifera are geographically and ecologically separated whereas their hybrids occur in intermediate habitats: A survey of 44 Chinese lakes
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DOI：
10.1111/mec.14991
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发表时间：
2019-02
影响因子：
4.9
通讯作者：
Xiaolin Ma;Wei Hu;P. Šmilauer;Mingbo Yin;J. Wolinska
中科院分区：
文献类型：
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作者：
Xiaolin Ma;Wei Hu;P. Šmilauer;Mingbo Yin;J. Wolinska
杂交促进分布范围扩大的观点最近受到关注，但来自实地研究的支持是有限的。我们假设，在枝水蚤属水蚤，亲本物种的地理和生态分离，而杂交种占据中间或偶尔极端的环境，可能促进范围扩大的亲本物种。利用线粒体标记和微卫星标记，对中国44个湖泊中的Daphnia dentifera、Daphnia galeata及其种间杂交种的分布进行了研究，并将其与湖泊地理和环境特征进行了关联。亲本种在地理上是分离的：D. dentifera分布于中国西部和中部，D. galeata分布在中国东部和中部，而杂种分布在中国西部和中部。然而，在控制了地理差异后，环境对物种分布的影响是强烈和显着的。具体来说，D. dentifera存在于高海拔贫营养湖泊中，D. galeata在低海拔富营养湖泊和杂交在中高海拔，主要是在中营养湖泊。微卫星数据表明，杂交种是本地产生的，而不是从别处迁移来的，它们可能是由于扩展D。galeata和居群D.齿本研究提供的证据表明，杂种可以生存在栖息地，否则只适合他们的父母种之一，强调杂交的重要性，在物种基因库的扩展。
The idea that hybridization promotes range expansion has received recent attention, but support from field studies is limited. We hypothesized that in the cladoceran waterflea genus Daphnia, parental species are geographically and ecologically separated, whereas hybrids occupy intermediate or occasionally extreme environments, potentially facilitating range expansion of parental species. We assessed the distribution of Daphnia dentifera, Daphnia galeata and their interspecific hybrids across 44 lakes in China (using mitochondrial and microsatellite markers), and related it to geographical and environmental lake descriptors. Parental species were geographically separated: D. dentifera occurred in western and central China, and D. galeata in eastern and central China, whereas hybrids were found in the western and central parts of the country. However, after controlling for geographical differences, the effect of environment on species distribution was strong and significant. Specifically, D. dentifera was present in high‐altitude oligotrophic lakes, D. galeata in low‐altitude eutrophic lakes and hybrids at intermediate to high altitudes, mainly in mesotrophic lakes. Microsatellite data indicated that hybrids were locally produced rather than having migrated from elsewhere; they probably resulted from encounters between expanding D. galeata and resident D. dentifera. The present study provides evidence that hybrids can survive in habitats that are otherwise suitable for only one of their parental species, emphasizing the importance of hybridization in expansion of species gene pools.