Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Department of Biology, Carleton University, Ottawa, Ontario, Canada.
Phytopathology. 2022 Aug;112(8):1795-1807. doi: 10.1094/PHYTO-09-21-0370-R. Epub 2022 Jun 17.
Variation in rate of infection and susceptibility of spp. to the fungus (syn. ), the causative agent of western gall rust, has been well documented. To test the hypothesis that there is a coevolutionary relationship between and its hosts, we examined genetic structure and virulence of associated with lodgepole pine ( var. ), jack pine (), and their hybrids. A secondary objective was to improve assessment and diagnosis of infection in hosts. Using 18 microsatellites, we assessed genetic structure of from 90 sites within the ranges of lodgepole pine and jack pine. We identified two lineages (East and West, = 0.677) associated with host genetic structure ( = 0.81, = 0.001), with East comprising three sublineages. In parallel, we conducted a factorial experiment in which lodgepole pine, jack pine, and hybrid seedlings were inoculated with spores from the two primary genetic lineages. With this experiment, we refined the phenotypic categories associated with infection and demonstrated that stem width can be used as a quantitative measure of host response to infection. Overall, each host responded differentially to the fungal lineages, with jack pine exhibiting more resiliency to infection than lodgepole pine and hybrids exhibiting intermediate resiliency. Taken together, the shared genetic structure between fungus and host species, and the differential interaction of the fungal species with the hosts, supports a coevolutionary relationship between host and pathogen.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
已充分证明，种的感染率和对真菌（即引起西部瘿锈病的病原体）的易感性存在差异。为了检验种与其宿主之间存在共同进化关系的假设，我们研究了与黑云杉（ var.）、短叶松（）及其杂种相关的与菌的遗传结构和毒力。次要目标是改进对宿主感染的评估和诊断。我们使用 18 个微卫星，评估了在黑云杉和短叶松分布范围内的 90 个地点的与菌的遗传结构。我们确定了与宿主遗传结构相关的两个谱系（东和西， = 0.677）（ = 0.81， = 0.001），其中东包括三个亚谱系。同时，我们进行了一项析因实验，在该实验中，用来自两个主要遗传谱系的孢子接种黑云杉、短叶松和杂种幼苗。通过该实验，我们细化了与感染相关的表型类别，并证明茎宽可用作宿主对感染反应的定量测量。总体而言，每个宿主对真菌谱系的反应不同，短叶松比黑云杉和杂种表现出更强的抗感染力。综上所述，真菌和宿主物种之间的共享遗传结构，以及真菌物种与宿主的不同相互作用，支持了宿主和病原体之间的共同进化关系。
