Laine Anna-Liisa, Burdon Jeremy J, Dodds Peter N, Thrall Peter H
CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia.
J Ecol. 2011 Jan;99(1):96-112. doi: 10.1111/j.1365-2745.2010.01738.x.
Variation in disease resistance is a widespread phenomenon in wild plant-pathogen associations. Here, we review current literature on natural plant-pathogen associations to determine how diversity in disease resistance is distributed at different hierarchical levels - within host individuals, within host populations, among host populations at the metapopulation scale and at larger regional scales.We find diversity in resistance across all spatial scales examined. Furthermore, variability seems to be the best counter-defence of plants against their rapidly evolving pathogens. We find that higher diversity of resistance phenotypes also results in higher levels of resistance at the population level.Overall, we find that wild plant populations are more likely to be susceptible than resistant to their pathogens. However, the degree of resistance differs strikingly depending on the origin of the pathogen strains used in experimental inoculation studies. Plant populations are on average 16% more resistant to allopatric pathogen strains than they are to strains that occur within the same population (48 % vs. 32 % respectively).Pathogen dispersal mode affects levels of resistance in natural plant populations with lowest levels detected for hosts of airborne pathogens and highest for waterborne pathogens.Detailed analysis of two model systems, Linum marginale infected by Melampsora lini, and Plantago lanceolata infected by Podosphaera plantaginis, show that the amount of variation in disease resistance declines towards higher spatial scales as we move from individual hosts to metapopulations, but evaluation of multiple spatial scales is needed to fully capture the structure of disease resistance.Synthesis: Variation in disease resistance is ubiquitous in wild plant-pathogen associations. While the debate over whether the resistance structure of plant populations is determined by pathogen-imposed selection versus non-adaptive processes remains unresolved, we do report examples of pathogen-imposed selection on host resistance. Here we highlight the importance of measuring resistance across multiple spatial scales, and of using sympatric strains when looking for signs of coevolution in wild plant-pathogen interactions.
抗病性的变异是野生植物与病原体相互关系中普遍存在的现象。在此，我们回顾了关于天然植物 - 病原体相互关系的现有文献，以确定抗病性的多样性在不同层次水平上是如何分布的——在寄主个体内、寄主种群内、集合种群尺度以及更大区域尺度上的寄主种群之间。我们发现在所有研究的空间尺度上都存在抗性多样性。此外，变异性似乎是植物抵御快速进化病原体的最佳防御手段。我们发现抗性表型的更高多样性也会导致种群水平上更高的抗性水平。总体而言，我们发现野生植物种群对其病原体更易感染而非具有抗性。然而，抗性程度因实验接种研究中所用病原体菌株的来源不同而有显著差异。植物种群对异地病原体菌株的抗性平均比对同一种群内出现的菌株高16%（分别为48%和32%）。病原体传播方式影响天然植物种群的抗性水平，其中气传病原体寄主的抗性水平最低，而水传病原体寄主的抗性水平最高。对两个模型系统的详细分析，即亚麻被亚麻栅锈菌感染以及车前草被车前白粉菌感染，表明随着我们从个体寄主转向集合种群，抗病性的变异量在更高空间尺度上呈下降趋势，但需要评估多个空间尺度才能全面把握抗病性结构。综述：抗病性变异在野生植物 - 病原体相互关系中普遍存在。虽然关于植物种群的抗性结构是由病原体施加的选择还是非适应性过程决定的争论仍未解决，但我们确实报告了病原体对寄主抗性施加选择的例子。在此，我们强调在多个空间尺度上测量抗性的重要性，以及在寻找野生植物 - 病原体相互作用中共进化迹象时使用同域菌株的重要性。
