Barrett Luke G, Thrall Peter H, Burdon Jeremy J
CSIRO Plant Industry, GPO Box 1600, Canberra, Australian Capital Territory, 2601, Australia.
Evolution. 2007 Jul;61(7):1613-21. doi: 10.1111/j.1558-5646.2007.00141.x.
Coevolutionary outcomes between interacting species are predicted to vary across landscapes, as environmental conditions, gene flow, and the strength of selection vary among populations. Using a combination of molecular, experimental, and field approaches, we describe how broad-scale patterns of environmental heterogeneity, genetic divergence, and regional adaptation have the potential to influence coevolutionary processes in the Linum marginale-Melampsora lini plant-pathogen interaction. We show that two genetically and geographically divergent pathogen lineages dominate interactions with the host across Australia, and demonstrate a hybrid origin for one of the lineages. We further demonstrate that the geographic divergence of the two lineages of M. lini in Australia is related to variation among lineages in virulence, life-history characteristics, and response to environmental conditions. When correlated with data describing regional patterns of variation in host resistance diversity and mating system these observations highlight the potential for gene flow and geographic selection mosaics to generate and maintain coevolutionary diversification in long-standing host-pathogen interactions.
由于环境条件、基因流动以及种群间选择强度存在差异，相互作用物种之间的协同进化结果预计会在不同景观中有所不同。我们结合分子、实验和野外方法，描述了环境异质性、遗传分化和区域适应性的广泛模式如何有可能影响亚麻（Linum marginale）-亚麻锈菌（Melampsora lini）植物-病原体相互作用中的协同进化过程。我们发现，在澳大利亚，两个遗传和地理上不同的病原体谱系主导着与宿主的相互作用，并证明其中一个谱系具有杂交起源。我们进一步证明，澳大利亚亚麻锈菌两个谱系的地理分化与谱系在毒力、生活史特征以及对环境条件的反应方面的差异有关。当与描述宿主抗性多样性和交配系统区域变化模式的数据相关联时，这些观察结果突出了基因流动和地理选择镶嵌体在长期宿主-病原体相互作用中产生和维持协同进化多样化的潜力。
