Exploring the impact of multidecadal environmental changes on the population genetic structure of a marine primary producer

Many marine protists form resting stages that can remain viable in coastal sediments for several decades. Their long-term survival offers the possibility to explore the impact of changes in environmental conditions on population dynamics over multidecadal time scales. Resting stages of the phototrophic dinoflagellate Pentapharsodinium dalei were isolated and germinated from five layers in dated sediment cores from Koljö fjord, Sweden, spanning ca. 1910–2006. This fjord has, during the last century, experienced environmental fluctuations linked to hydrographic variability mainly driven by the North Atlantic Oscillation. Population genetic analyses based on six microsatellite markers revealed high genetic diversity and suggested that samples belonged to two clusters of subpopulations that have persisted for nearly a century. We observed subpopulation shifts coinciding with changes in hydrographic conditions. The large degree of genetic diversity and the potential for both fluctuation and ...许多海洋原生生物会形成休眠体，这类休眠体可在沿岸沉积物中存活数十年之久。这类休眠体的长期留存，为研究数十年尺度下环境条件变化对种群动态的影响提供了可能。研究人员从瑞典科尔约（Koljö）峡湾的年代测定沉积物岩芯的五个层位中，分离并萌发了光合甲藻（phototrophic dinoflagellate）*Pentapharsodinium dalei*的休眠体；该岩芯的沉积年代跨度约为1910年至2006年。近一个世纪以来，该峡湾经历了与水文变化相关的环境波动，而这些水文变化主要受北大西洋涛动（North Atlantic Oscillation）驱动。基于6个微卫星标记（microsatellite marker）的群体遗传分析结果显示，供试样本具有较高的遗传多样性，且可划分为两个持续存在了近一个世纪的亚种群簇。研究人员观察到，亚种群的转变与水文条件的变化相吻合。该类群具备极高的遗传多样性，且兼具种群波动与……的潜在可能性。