Tack Ayco J M, Laine Anna-Liisa, Burdon Jeremy J, Bissett Andrew, Thrall Peter H
Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91, Stockholm, Sweden.
Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), FI-00014, Helsinki, Finland.
New Phytol. 2015 Sep;207(4):1159-69. doi: 10.1111/nph.13408. Epub 2015 Apr 13.
We investigated the impact of below-ground and above-ground environmental heterogeneity on the ecology and evolution of a natural plant-pathogen interaction. We combined field measurements and a reciprocal inoculation experiment to investigate the potential for natural variation in abiotic and biotic factors to mediate infection outcomes in the association between the fungal pathogen Melampsora lini and its wild flax host, Linum marginale, where pathogen strains and plant lines originated from two ecologically distinct habitat types that occur in close proximity ('bog' and 'hill'). The two habitat types differed strikingly in soil moisture and soil microbiota. Infection outcomes for different host-pathogen combinations were strongly affected by the habitat of origin of the plant lines and pathogen strains, the soil environment and their interactions. Our results suggested that tradeoffs play a key role in explaining the evolutionary divergence in interaction traits among the two habitat types. Overall, we demonstrate that soil heterogeneity, by mediating infection outcomes and evolutionary divergence, can contribute to the maintenance of variation in resistance and pathogenicity within a natural host-pathogen metapopulation.
我们研究了地下和地上环境异质性对自然植物-病原体相互作用的生态和进化的影响。我们结合了实地测量和相互接种实验，以研究非生物和生物因素的自然变异在介导真菌病原体亚麻栅锈菌（Melampsora lini）与其野生亚麻宿主边缘亚麻（Linum marginale）之间的关联中感染结果的潜力，其中病原体菌株和植物品系源自两个紧密相邻的生态上不同的栖息地类型（“沼泽”和“山丘”）。这两种栖息地类型在土壤湿度和土壤微生物群方面存在显著差异。不同宿主-病原体组合的感染结果受到植物品系和病原体菌株的起源栖息地、土壤环境及其相互作用的强烈影响。我们的结果表明，权衡在解释两种栖息地类型之间相互作用性状的进化差异中起着关键作用。总体而言，我们证明土壤异质性通过介导感染结果和进化差异，有助于维持自然宿主-病原体集合种群内抗性和致病性的变异。
