Australian Institute of Marine Science, Townsville, Queensland, Australia.
AIMS@JCU, James Cook University of North Queensland, Townsville, Queensland, Australia.
PeerJ. 2024 Nov 12;12:e18273. doi: 10.7717/peerj.18273. eCollection 2024.
Marine heatwaves are becoming more frequent during summer and pose a significant threat to coral reef ecosystems. Restoration efforts have the potential to support native coral populations and guard them against some degree of environmental change, while global action against climate change takes place. Interspecific hybridization is one approach through which resilient coral stock could be generated for restoration. Here we compared the performance of and hybrid and purebred coral recruits under a simulated thermal stress event. eggs were successfully fertilized by sperm to produce 'KL' hybrids, but no 'LK' hybrids could be produced from eggs and sperm. Despite corals in the elevated treatment accruing thermal stress (>12 degree heating weeks over 2 months) known to result in mass bleaching, both purebred and hybrid recruits showed no signs of stress under the simulated temperature regime, based on the performance indicators survivorship, size, color (a proxy of bleaching), and photochemical efficiency of photosystem II. Comparisons between the hybrids and purebreds studied here must be interpreted with caution because hybrid sample sizes were small. The hybrids did not outperform both of their purebred counterparts for any metrics studied here, demonstrating that there are limitations to the extent to which interspecific hybridization may boost the performance of coral stock. In general, the purebred recruits performed best under both ambient and elevated conditions. The performance of the KL hybrid corals was similar to the maternal parental species, , or not significantly different to either parental purebred species. The Symbiodiniaceae communities of the KL hybrids were characteristic of their maternal counterparts and may have underpinned the performance differences between the /KL hybrid and recruits.
海洋热浪在夏季变得越来越频繁，对珊瑚礁生态系统构成了重大威胁。恢复工作有可能支持本地珊瑚种群，并在全球采取行动应对气候变化的同时，对其进行一定程度的环境变化保护。种间杂交是一种可以产生有弹性的珊瑚种群以进行恢复的方法。在这里，我们比较了 和 杂种和纯种珊瑚幼体在模拟热应激事件下的表现。成功地用 精子使 卵子受精，产生了“KL”杂种，但不能从 卵子和 精子产生“LK”杂种。尽管在已知会导致大规模白化的升高处理中，珊瑚积累了热应激（2 个月内超过 12 度的加热周），但根据生存能力、大小、颜色（白化的替代物）和光系统 II 的光化学效率等表现指标，纯种和杂种幼体在模拟温度条件下均未表现出应激迹象。由于杂种的样本量较小，因此必须谨慎解释这里研究的杂种与纯种之间的比较。杂种在任何研究指标上均未优于其两个纯种亲本，这表明种间杂交在提高珊瑚种群性能方面存在局限性。一般来说，在环境和升高条件下，纯种 幼体表现最佳。KL 杂种珊瑚的表现与母本种 相似，或与任何一个纯种亲本种均无显著差异。KL 杂种的共生体群落与其母本相似，可能是 /KL 杂种和 幼体之间表现差异的基础。
