A geographic mosaic of genetic variation within a foundation tree species and its community-level consequences
A geographic mosaic of genetic variation within a foundation tree species and its community-level consequences
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DOI：
10.1890/08-0951.1
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发表时间：
2009-07-01
期刊：
影响因子：
4.8
通讯作者：
Potts, Bradley M.
中科院分区：
文献类型：
--
作者：
Barbour, Robert C.;O'Reilly-Wapstra, Julianne M.;Potts, Bradley M.
了解一个树种内的遗传变异如何影响整个范围内的相关群落和生态系统过程，对于理解遗传相互作用的地理镶嵌如何发展和支持不同的群落是很重要的。虽然许多研究已经调查了社区和生态系统的遗传变异的后果在杂交类型或基因型水平的物种，没有调查的群落水平的影响种内遗传变异的地理范围广泛的物种。这就是共同进化的地理马赛克被假设存在的规模。这一水平的研究对基础树种特别重要，因为基础树种通常支持许多微生物、真菌、植物和动物群落。我们研究了8个地理种族的林木蓝桉代表其自然分布在澳大利亚东南部的遗传变异。这项研究是在一个15岁的共同花园试验的基础上，家庭来自单树开放授粉的种子收集从野生。E.同时，还对蓝球种的表型和群落性状进行了遗传多样性分析和比较。出现了三个主要发现。首先，我们发现了显着的遗传基础上，层次变化相对应的地理种族的E相关社区。种族内的族群。第二，在种族水平上的叶面群落的分歧与遗传基础上的分歧，在特定的叶形态和化学性状，具有已知的防御功能。第三，冠层群落差异与中性分子遗传差异和叶数量遗传差异在小种水平上均呈显著正相关，支持遗传相似性规则。我们的研究结果认为，基础树种内的遗传变异有可能成为森林群落典型变异的地理镶嵌的重要驱动力，这可能具有重要的生态和进化意义。
Knowledge of the manner in which genetic variation within a tree species affects associated communities and ecosystem processes across its entire range is important for understanding how geographic mosaics of genetic interactions might develop and support different communities. While numerous studies have investigated the community and ecosystem consequences of genetic variation at the hybrid cross type or genotype level within a species, none has investigated the community-level effects of intraspecific genetic variation across the geographic range of a widespread species. This is the scale at which geographic mosaics of coevolution are hypothesized to exist. Studies at this level are particularly important for foundation tree species, which typically support numerous microbial, fungal, plant, and animal communities. We studied genetic variation across eight geographical races of the forest tree Eucalyptus globulus representing its natural distribution across southeastern Australia. The study was conducted in a 15-year-old common garden trial based on families derived from single-tree open-pollinated seed collections from the wild. Neutral molecular genetic variation within E. globulus was also assessed and compared with genetic divergence in the phenotypic and community traits. Three major findings emerged. First, we found significant genetically based, hierarchical variation in associated communities corresponding to geographical races of E. globulus and families within races. Second, divergence in foliar communities at the racial level was associated with genetically based divergence in specific leaf morphological and chemical traits that have known defensive functions. Third, significant positive correlations between canopy community dissimilarity and both neutral molecular genetic and leaf quantitative genetic dissimilarity at the race level supported a genetic similarity rule. Our results argue that genetic variation within foundation tree species has the potential to be a significant driver of the geographical mosaics of variation typical of forest communities, which could have important ecological and evolutionary implications.