Exploring resistance mechanisms in the S. musiva - Populus interaction

在过去几十年中，世界对木材和纤维等森林产品的需求增加，而可用于帮助满足这些需求的相应土地面积减少。因此，林业公司已开始探索种植园林，作为抵消可用土地减少的一种手段，同时保持稳定的纤维生产。快速生长的杂交白杨种植园一直是加拿大各地的首选树种。然而，这些树种种植园的增加往往伴随着虫害和疾病爆发的增加。特别令人感兴趣的是一种叫做壳针孢溃疡病病原体的疾病。虽然这种疾病感染叶子，引起叶斑，和木质组织，引起溃疡，但大多数经济上重要的损害是木质组织上的溃疡的结果。显然需要研究杨树-壳针孢属病原体相互作用的基本和应用方面，以及对加拿大杂交白杨人工林潜在的短期和长期成功的明显影响。我们建议进行多项研究，以更好地了解壳针孢-杨树相互作用，减少对白杨人工林的损害，从而提高纤维生产的质量和数量。本研究主要包括以下几个方面：（1）对毛壳针孢病原菌及不同株系的人工杂种杨树进行了广泛的遗传分析。这将提供在其范围内的病原体群体遗传学的描述，然后可以将其与病原体的疾病严重性进行比较，（2）描述壳针孢属病原体进入宿主组织并引起疾病的模式，以及（3）通过比较抗性和敏感树木在暴露于不同菌株后产生的防御化学物质，研究白杨的抗性机制。病原体我们预计，该项目的结果将有助于更广泛的社区参与白杨疾病管理和更有针对性的社区壳针孢病原体调查和白杨种植者在加拿大，以及由此产生的信息将支持纤维管理策略的发展，旨在减少因壳针孢溃疡病的损失。

Over the last several decades world demand for forest products such as timber and fiber have increased and the corresponding land area available to help meet these demands has decreased. As a result forest companies have begun to explore plantation forestry as a means of offsetting the reduction in land available while maintain a steady fiber production. Plantations of fast growing hybrid poplar have been the species of choice across Canada. However, the increased plantation of these tree species is often accompanied by an increased insect and disease outbreaks. Of particular interest is a disease called Septoria canker pathogen. While this disease infects leaves, causing leaf spots, and woody tissue, causing cankers, the majority of the economically important damage is a result of cankers on woody tissues. Studies focusing on both fundamental and applied aspects of poplar-Septoria pathogen interaction in combination with clear impacts on the potential short- and long- term success of hybrid poplar plantations in Canada are clearly needed. We propose multiple studies to develop a better understanding of Septoria-poplar interactions and reduce damage to poplar plantations, and thus improve quality and quantity of fiber production. In our studies, we will (1) investigate a range-wide genetic analysis of the Septoria pathogen and artificially inoculate hybrid poplars with different strains of the pathogen. This will provide a description of the pathogen population genetics across its range, which can then be compared with disease severity of the pathogen, (2) describe the mode by which the Septoria pathogen enters into host tissue and causes disease, and (3) examine the resistance mechanism employed by poplar trees by comparing the defensive chemicals produced by resistant and susceptible trees after exposure to different strains of the pathogen. We expect that the outcome of this project will be useful to a broader community involved in poplar disease management and a more targeted community of Septoria pathogen investigators and poplar growers in Canada, as well as the resulting information will support the development of fiber management strategies that are aimed at reducing losses due to Septoria canker.