2005年，我国欧美杨上发现一种新的危害非常严重的溃疡病，国内外均无相关报道，为区别于传统的杨树溃疡病，现将其命名为欧美杨细菌性溃疡型烂皮病。该病害不仅病斑扩展速度快，且2-3周内能导致树皮的大面积腐烂，其如何致病？机制是什么？是否存在多种协同致病菌？为回答上述问题，本项目将开展以下两方面的研究：.1)利用分离鉴定和现代分子生物学技术（基因文库分析）相结合的方法分析病组织中微生物多样性状况,包括以下3项研究内容：①病组织不同部位的微生物多样性分析；②接种病原细菌的植株病组织中微生物多样性随时间的动态变化分析；③可培养未知种细菌的分类鉴定。.2)利用接种和宏基因组学方法开展病组织中各类微生物的作用及其协同致病机制研究。.本研究旨在弄清欧美杨细菌性溃疡型烂皮病病组织中协同致病菌的种类及其在致病作用，探明其致病机制，为该病害防治方法和针对性地防治对策的制定奠定基础。

A new disease of poplar trees (Populus×euramericana) showing serious bark cankers with copious exudations was first oberved in China in 2005. And no related reports obout the disease were found in all the world. The disease extended at a very fast speed, and the large area of rotten bark would be oberved within 2-3 weeks from the very beginning. What is mechanism the pathogen? Are there other pathogenic microbiology? To understanding key issues, two studies will be carried out in present project. .1) Micorbial diversity of barker canker tissues, including micorbial diversity of different parts of canker tissues and fluctuations of microbial diversity of the tissue after inoculation of pathogen, will be performed by the integration of 16S rRNA and 18S rRNA gene libary - and culture-based approaches. And, the unpublished bacterial species will be classified. .2) The potential roles of the micorbiology in the canker tissue and their pathogenesis will be analyzed by the integration of metagenomics- and inoculation-based approaches with the poplar trees. The present research will ascertain how many species are potential pathogen, and what are their collaborative roles. And the results of this study will contribute the research about disease contol and ocurrence of disease.