Department of Biology, University of Virginia, Charlottesville, Virginia 22904, USA.
Evolution. 2011 Feb;65(2):512-22. doi: 10.1111/j.1558-5646.2010.01146.x. Epub 2010 Nov 5.
Five levels of disease expression were scored in a cross-inoculation study of 120 host and 60 pathogen lines of wild flax Linum marginale and its rust fungus Melampsora lini sampled from six natural populations. Patterns of partial resistance showed clear evidence of gene-for-gene interactions, with particular levels of partial resistance occurring in specific host-pathogen combinations. Sympatric and putatively more highly coevolved host-pathogen combinations had a lower frequency of partial resistance types relative to allopatric combinations. Sympatric host-pathogen combinations also showed a lower diversity of resistance responses, but there was a trend toward a greater fraction of this variance being determined by pathogen-genotype × host-genotype interactions. In this system, there was no evidence that partial resistances slow host-pathogen coevolution. The analyses show that if variation is generated by among population host or pathogen dispersal, then coevolution occurs largely by pathogens overcoming the partial resistances that are generated.
在对来自六个自然种群的 120 个亚麻宿主和 60 个亚麻锈菌（Melampsora lini）品系进行交叉接种研究中，对疾病表现的五个水平进行了评分。部分抗性模式显示出明显的基因对基因相互作用的证据，特定水平的部分抗性出现在特定的宿主-病原体组合中。同域且可能经历了更高程度协同进化的宿主-病原体组合相对于异域组合具有较低频率的部分抗性类型。同域宿主-病原体组合还表现出较低的抗性反应多样性，但宿主-病原体基因型相互作用决定了这种变异的更大比例，这是一种趋势。在这个系统中，没有证据表明部分抗性会减缓宿主-病原体的协同进化。分析表明，如果变异是由种群间的宿主或病原体扩散产生的，那么协同进化主要是通过病原体克服产生的部分抗性来实现的。
