Rossetto M, Crayn D, Ford A, Mellick R, Sommerville K
National Herbarium of NSW, Botanic Gardens Trust, Sydney, NSW, Australia.
Mol Ecol. 2009 Apr;18(7):1422-38. doi: 10.1111/j.1365-294X.2009.04111.x.
This study investigates patterns of genetic connectivity among 11 co-distributed tropical rainforest tree species from the genus Elaeocarpus across a biogeographic barrier, the Black Mountain Corridor (BMC) in the Australian Wet Tropics (AWT). We analysed a combination of allelic and flanking region sequence data from microsatellite markers, and evaluated the relative influence of environmental preferences and functional traits on genetic diversity and gene flow. The results indicate that only in three species geographic structuring of haplotype distribution reflects a north vs. south of the BMC pattern. Environmental factors linked with altitude were recognized as affecting genetic trends, but the selective processes operating on upland species appear to be associated with competitiveness and regeneration opportunities on poor soil types rather than climate variables alone. In contrast to previous observations within southeastern Australian rainforests, genetic differentiation in the AWT appears to be associated with small-fruited rather than large-fruited species, highlighting how external factors can influence the dispersal dimension. Overall, this study emphasizes the importance of considering functional and environmental factors when attempting generalizations on landscape-level patterns of genetic variation. Understanding how plant functional groups respond to environmental and climatic heterogeneity can help us predict responses to future change.
本研究调查了11种共同分布的杜英属热带雨林树种在跨越澳大利亚湿热带地区（AWT）的一个生物地理屏障——黑山走廊（BMC）时的遗传连通模式。我们分析了来自微卫星标记的等位基因和侧翼区域序列数据的组合，并评估了环境偏好和功能性状对遗传多样性和基因流的相对影响。结果表明，只有三个物种的单倍型分布的地理结构反映了BMC模式的北部与南部。与海拔相关的环境因素被认为影响遗传趋势，但作用于高地物种的选择过程似乎与贫瘠土壤类型上的竞争力和再生机会有关，而不仅仅是气候变量。与之前在澳大利亚东南部雨林中的观察结果相反，AWT中的遗传分化似乎与小果物种而非大果物种有关，这突出了外部因素如何影响扩散维度。总体而言，本研究强调了在试图概括遗传变异的景观水平模式时考虑功能和环境因素的重要性。了解植物功能群如何应对环境和气候异质性有助于我们预测对未来变化的反应。
