Experimental responses to elevated water temperature in genotypes of the reef coral Pocillopora damicornis from upwelling and non-upwelling environments in Panama
Experimental responses to elevated water temperature in genotypes of the reef coral Pocillopora damicornis from upwelling and non-upwelling environments in Panama
复制标题
DOI：
10.1007/s00338-004-0397-7
复制
发表时间：
2004-12-01
期刊：
影响因子：
3.5
通讯作者：
Maté, JL
中科院分区：
文献类型：
--
作者：
D'Croz, L;Maté, JL
作者调查了来自巴拿马湾上升流的三个珊瑚礁和巴拿马太平洋奇里基非上升流海湾的四个珊瑚礁的Pocillopora damicornis基因型对实验升高水温的反应。在季节性上升流期间，巴拿马湾的海面温度下降到20摄氏度以下，而在热稳定的奇里基湾，温度在27至29摄氏度之间。利用等位酶电泳技术对7个地点的黄角原甲进行了基因型分析。在每个地点选择最丰富的基因型进行耐热实验，珊瑚暴露在30摄氏度（高于环境温度1摄氏度）的水温下43天。四个网站的珊瑚基因型可以独特地区分由GPI基因座，两个由LGG-2基因座，和两个由MDH-1，LGG-2，和LTY-3基因座的组合。对暴露于高温后的珊瑚状况进行的目视评估表明，来自非上升流环境的珊瑚保持正常至略苍白的外观，而来自上升流环境的珊瑚则漂白，珊瑚虫大多收缩。双向方差分析证实，珊瑚显着影响水温和地点。温度升高和珊瑚的位置对虫黄藻的生长也有显著的影响。平均zooxanthropium密度下降了25%和55%，分别在实验加热珊瑚从非上升流和上升流环境。在高温下，珊瑚每活面积的光合色素浓度低是正常的。叶绿素a的平均浓度每活面积的珊瑚减少了17和49%，分别在加热珊瑚从非上升流和上升流网站。从上升流的巴拿马湾的珊瑚基因型表现出更高的脆弱性，热应力比珊瑚基因型从非上升流的奇里基湾。然而，后者的答复差异较大。因此，即使在很小的地理尺度上，珊瑚也可以表现出不同程度的热应力耐受性。上升流和非上升流环境中的珊瑚之间的耐热性的差异是伴随着更大的遗传差异，实验珊瑚从热稳定的奇里基湾相比，从巴拿马湾上升流的珊瑚。
The authors investigated the response to experimentally elevated water temperature in genotypes of Pocillopora damicornis from three coral reefs in the upwelling Gulf of Panama and four coral reefs in the non-upwelling Gulf of Chiriqui, Panamanian Pacific. Sea-surface temperature in the Gulf of Panama declines below 20 degreesC during seasonal upwelling, while in the thermally stable Gulf of Chiriqui, the temperature ranges from 27 to 29 degreesC. Genotypes of P. damicornis from the seven locations were determined by allozyme electrophoresis. The most abundant genotype at each location was selected for a thermal tolerance experiment where corals were exposed to water temperature of 30 degreesC (1 degreesC above ambient) for 43 days. Four site coral genotypes can be uniquely differentiated by the GPI locus, two by the LGG-2 locus, and two by a combination of the MDH-1, LGG-2, and LTY-3 loci. A visual assessment of the coral condition after exposure to an elevated temperature showed that corals from localities in the non-upwelling environment retained a normal to slightly pale appearance, while corals from the upwelling environment bleached and their polyps were mostly retracted. A two-way ANOVA confirmed that corals were significantly affected by water temperature and locality. The zooxanthellae were also significantly affected by the interaction of elevated temperature and locality of the corals. Mean zooxanthellae density decreased by 25 and 55%, respectively, in experimentally heated corals from the non-upwelling and upwelling environments. Low concentrations of photosynthetic pigments per live area of the corals were the norm in corals under elevated temperature. The mean concentration of chlorophyll a per live area of the corals was reduced by 17 and 49%, respectively, in heated corals from the non-upwelling and upwelling sites. Coral genotypes from the upwelling Gulf of Panama demonstrated higher vulnerability to thermal stress than coral genotypes from the non-upwelling Gulf of Chiriqui. However, the latter showed greater differences in their responses. Thus, even at small geographic scales, corals can display different levels of tolerance to thermal stress. The difference in thermal tolerance between corals from upwelling and non-upwelling environments is concomitant with greater genetic differences in experimental corals from the thermally stable Gulf of Chiriqui compared with corals from the upwelling Gulf of Panama.