Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), FI-00014, Helsinki, Finland.
New Phytol. 2014 Apr;202(1):297-308. doi: 10.1111/nph.12646. Epub 2013 Dec 23.
While recent studies have elucidated many of the factors driving parasite dynamics during the growing season, the ecological and evolutionary dynamics during the off-season (i.e. the period between growing seasons) remain largely unexplored. We combined large-scale surveys and detailed experiments to investigate the overwintering success of the specialist plant pathogen Podosphaera plantaginis on its patchily distributed host plant Plantago lanceolata in the Åland Islands. Twelve years of epidemiological data establish the off-season as a crucial stage in pathogen metapopulation dynamics, with c. 40% of the populations going extinct during the off-season. At the end of the growing season, we observed environmentally mediated variation in the production of resting structures, with major consequences for spring infection at spatial scales ranging from single individuals to populations within a metapopulation. Reciprocal transplant experiments further demonstrated that pathogen population of origin and overwintering site jointly shaped infection intensity in spring, with a weak signal of parasite adaptation to the local off-season environment. We conclude that environmentally mediated changes in the distribution and evolution of parasites during the off-season are crucial for our understanding of host-parasite dynamics, with applied implications for combating parasites and diseases in agriculture, wildlife and human disease systems.
虽然最近的研究已经阐明了许多驱动寄生虫在生长季节动态的因素，但在淡季（即生长季节之间的时期）的生态和进化动态在很大程度上仍未得到探索。我们结合了大规模调查和详细实验，研究了专家植物病原体 Podosphaera plantaginis 在其在阿拉斯加岛屿上呈斑块状分布的宿主植物 Plantago lanceolata 上的越冬成功。十二年的流行病学数据确立了淡季是病原体亚种群动态的关键阶段，约有 40%的种群在淡季灭绝。在生长季节结束时，我们观察到与环境有关的休眠结构产生的变化，这对从单个个体到亚种群内的种群等空间尺度的春季感染产生了重大影响。互惠移植实验进一步表明，病原体种群起源和越冬地点共同塑造了春季的感染强度，而寄生虫对当地淡季环境的适应信号较弱。我们的结论是，淡季期间寄生虫分布和进化的环境介导变化对于我们理解宿主-寄生虫动态至关重要，这对农业、野生动物和人类疾病系统中防治寄生虫和疾病具有应用意义。
