Burdon Jeremy J, Thrall Peter H
CSIRO Plant Industry Canberra, ACT, Australia.
Evol Appl. 2008 Feb;1(1):57-65. doi: 10.1111/j.1752-4571.2007.00005.x.
Infectious disease is a major causal factor in the demography of human, plant and animal populations. While it is generally accepted in medical, veterinary and agricultural contexts that variation in host resistance and pathogen virulence and aggressiveness is of central importance to understanding patterns of infection, there has been remarkably little effort to directly investigate causal links between population genetic structure and disease dynamics, and even less work on factors influencing host-pathogen coevolution. The lack of empirical evidence is particularly surprising, given the potential for such variation to not only affect disease dynamics and prevalence, but also when or where new diseases or pathotypes emerge. Increasingly, this lack of knowledge has led to calls for an integrated approach to disease management, incorporating both ecological and evolutionary processes. Here, we argue that plant pathogens occurring in agro-ecosystems represent one clear example where the application of evolutionary principles to disease management would be of great benefit, as well as providing model systems for advancing our ability to generalize about the long-term coevolutionary dynamics of host-pathogen systems. We suggest that this is particularly the case given that agro-ecological host-pathogen interactions represent a diversity of situations ranging from those that only involve agricultural crops through to those that also include weedy crop relatives or even unrelated native plant communities. We begin by examining some of the criteria that are important in determining involvement in agricultural pathogen evolution by noncrop plants. Throughout we use empirical examples to illustrate the fact that different processes may dominate in different systems, and suggest that consideration of life history and spatial structure are central to understanding dynamics and direction of the interaction. We then discuss the implications that such interactions have for disease management in agro-ecosystems and how we can influence those outcomes. Finally, we identify several major gaps where future research could increase our ability to utilize evolutionary principles in managing disease in agro-ecosystems.
传染病是影响人类、植物和动物种群数量的一个主要因素。在医学、兽医学和农业领域，人们普遍认为宿主抗性以及病原体毒力和侵袭力的变化对于理解感染模式至关重要，但直接研究种群遗传结构与疾病动态之间因果关系的工作却非常少，而关于影响宿主 - 病原体协同进化因素的研究更是少之又少。鉴于这种变异不仅可能影响疾病动态和流行程度，还可能影响新疾病或致病型出现的时间和地点，缺乏实证证据尤其令人惊讶。越来越多的情况是，这种知识的匮乏促使人们呼吁采用一种综合方法来进行疾病管理，将生态和进化过程都纳入其中。在此，我们认为农业生态系统中的植物病原体就是一个明显的例子，将进化原理应用于疾病管理将大有裨益，同时也能为提升我们概括宿主 - 病原体系统长期协同进化动态的能力提供模型系统。我们认为尤其如此，因为农业生态中的宿主 - 病原体相互作用涵盖了多种情形，从仅涉及农作物的情况到还包括杂草类作物近缘种甚至不相关的本地植物群落的情况。我们首先审视一些在确定非农作物对农业病原体进化影响方面很重要的标准。在整个论述过程中，我们使用实证例子来说明不同过程可能在不同系统中占主导地位，并指出考虑生活史和空间结构对于理解相互作用的动态和方向至关重要。然后，我们讨论这种相互作用对农业生态系统中疾病管理的影响以及我们如何能够影响这些结果。最后，我们指出了几个主要的差距，未来的研究可以在这些方面提高我们在农业生态系统疾病管理中运用进化原理的能力。
