Exploring the role of asexual multiplication in poplar rust epidemics: impact on diversity and genetic structure

Fungal plant pathogens, especially rust fungi (Pucciniales), are well known for their complex life cycles, which include phases of sexual and asexual reproduction. The effect of asexual multiplication on population genetic diversity has been investigated in the poplar rust fungus Melampsora larici-populina using a nested hierarchical sampling scheme. Four hierarchical levels were considered: leaf, twig, tree and site. Both cultivated and wild poplar stands were sampled at two time points at the start and end of rust epidemics. A total of 641 fungal isolates was analyzed using ten microsatellite markers. This study revealed that the genetic signature of asexual multiplication in the wild poplar stand was seen only at lower hierarchical levels (leaf and twig). The observed change in clonal structure, displaying an increase in both gene and genotypic diversity, demonstrates that, despite the fact that only asexual multiplication occurs during the epidemic phase, new genotypes contribute to...

植物病原真菌，尤其是锈菌（Pucciniales），以其兼具有性与无性繁殖阶段的复杂生活史而广为人知。本研究以落叶松-杨栅锈菌（Melampsora larici-populina）为对象，采用嵌套分层采样方案，探究了无性繁殖对其种群遗传多样性的影响。本次采样设置了四级分层单元：叶片、枝条、植株与样地。研究在锈病流行期的起始与结束两个时间节点，对栽培与野生杨树林分进行了采样，共获取641株真菌分离物，并利用10个微卫星标记（microsatellite markers）对其进行了遗传分析。结果显示，野生杨树林分中无性繁殖的遗传信号仅在较低层级的采样单元（叶片与枝条）中被检出。本研究观测到的克隆结构变化表现为基因多样性与基因型多样性均有所提升，这表明尽管锈病流行阶段仅存在无性繁殖，但新基因型仍可对……