Indian Oceans Marine Research Centre, Australian Institute of Marine Science, Crawley, WA, Australia.
Trace and Environmental DNA Laboratory, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia.
Mol Ecol. 2018 Apr;27(7):1586-1602. doi: 10.1111/mec.14559. Epub 2018 Apr 17.
The predominance of self-recruitment in many reef-building corals has fundamental and complex consequences for their genetic diversity, population persistence and responses to climate change. Knowledge of genetic structure over local scales needs to be placed within a broad spatial context, and also integrated with genetic monitoring through time to disentangle these consequences. Here, we examined patterns of genetic diversity over multiple spatio-temporal scales across tropical Australia in the ubiquitous brooding coral, Seriatopora hystrix. We also analysed complimentary environmental and demographic data to elucidate the seascape drivers of these patterns. Large genetic differences were detected between the east vs. west coasts of Australia. In northwest Australia, geographic differentiation dominated genetic structure over multiple scales. However, three sympatric lineages were detected at the largest offshore reef system (Scott Reef). Similar to the differences observed among putative species in eastern Australia, these lineages were associated with different levels of wave exposure. Local genetic structure within the Scott Reef system was relatively stable over 10 years, but temporal differences were observed that reflected small but important genetic changes over a few generations during recovery after severe bleaching. These results highlight the importance of self-recruitment together with occasional longer distance connectivity for the persistence of a metapopulation across spatially and temporally variable environments. Our multidimensional research provides a foundation for further long-term genetic monitoring to inform conservation strategies and highlights that sampling scales, ecological effects and cryptic diversity are important considerations to develop realistic understanding of the evolutionary resilience of corals.
在许多造礁珊瑚中，自我招募的优势对其遗传多样性、种群持久性以及对气候变化的响应具有根本和复杂的影响。需要将局部尺度的遗传结构知识置于广泛的空间背景下，并与随时间的遗传监测相结合，以理清这些后果。在这里，我们研究了在澳大利亚热带地区广泛存在的珊瑚 Seriatopora hystrix 在多个时空尺度上的遗传多样性模式。我们还分析了补充的环境和人口数据，以阐明这些模式的海景驱动因素。在澳大利亚东海岸和西海岸之间检测到很大的遗传差异。在澳大利亚西北部，地理分化在多个尺度上主导着遗传结构。然而，在最大的近海珊瑚礁系统（斯科特礁）中检测到了三个共生谱系。与在澳大利亚东部观察到的假定物种之间的差异相似，这些谱系与不同水平的波浪暴露有关。在斯科特礁系统内，局部遗传结构在 10 年内相对稳定，但观察到了时间差异，这些差异反映了在严重白化后恢复过程中几代人之间的微小但重要的遗传变化。这些结果强调了自我招募以及偶尔的长距离连通性对于在空间和时间上变化的环境中维持一个复合种群的持久性的重要性。我们的多维研究为进一步的长期遗传监测提供了基础，以告知保护策略，并强调采样尺度、生态效应和隐生多样性是发展对珊瑚进化弹性的现实理解的重要考虑因素。
