中国丽赤壳属Calonectria种类及系统发育研究

The genus Calonectria is one of the most important pathogens causing extensive damage of numerous plant hosts worldwide. Many researchers have done much work on the genus Calonectria overseas, while limited research on Calonectria has been conducted in China. In this project, several isolates of Calonectria will be identified through morphological characteristics and DNA sequences comparisons based on the collection of Calonectria isolates from several hosts in various geographic regions. The genome information of one isolate HSMZH01 was acquired by Illumina/Solexa sequencing and bioinformatics analysis hence several unique genes using for identification of doubtful species and similar species will be obtained through comparative genomics method. Furthermore, phylogenetic relationships among several Calonectria spp. will be achieved by multigene analyses. This study focuses on identification of the Calonectria species pathogen in China and figuring out their phylogenetic relationships. The results of this study are constructive to enrich fungal pathogen resources in China and the taxonomy of Calonectria spp., additionally this research will be helpful to identification of plant pathogens and controls of the plant diseases.

丽赤壳属（Calonectria De Not.）是一类重要的植物病原菌，该属真菌在生产上可造起严重的危害，引起重大的经济损失。国外学者对Calonectria进行了深入、系统的研究，国内相关研究则较少。本项目拟对中国丽赤壳属真菌开展系统研究，在广泛采集样品和分离菌株的基础上，通过形态学和DNA序列分析对丽赤壳属真菌进行种类鉴定；在对实验室已获得菌株HSMZH01进行全基因组测序的基础上，通过基因组比较分析，筛选获得疑难种和近似种的鉴别基因；进一步通过多基因联合分析的方法对相关种群进行系统发育分析。本研究可明确中国丽赤壳属真菌的种类和相关种群的亲缘关系，丰富我国真菌资源库，完善丽赤壳属的分类体系，并可为生产上病害的正确诊断和科学防治提供理论指导。

丽赤壳属（Calonectria）是一类重要的植物病原菌，该属真菌在生产上可造程严重危害，引致重大的经济损失。国外学者对该属真菌进行了深入系统的研究，国内相关研究较少，主要集中在桉树相关的种类上。本项目对中国丽赤壳属真菌开展系统研究，主要结果如下：.研究采集丽赤壳属疑似样品737份，共分离获得82个丽赤壳属菌株。通过标准培养条件下的形态学特征观察及DNA序列分析，将82个菌株鉴定为20个种，包括8个新种：C. callistemonii，C. cassiana ，C. ficusia，C. huoluensis ，C. melaeucae，C. spathiphyllicola，C. tibouchinae 和C. yushaensis 。联合CAL、TEF-1α和TUB2构建多基因系统发育树，进行系统发育分析，20个种聚为6大分支，归属于6个复合群：C. colhounii 复合群，C. cylindrospora 复合群，C. kyotensis 复合群，C. reteaudii 复合群，C. brassicae 复合群 和C. spathiphylii 复合群。同时致病性测定发现，20个种中18个种分别为21个寄主的新致病菌，包括生产上为害严重的花生黑腐病和白掌褐腐病分别发现2个新致病种类。以上研究不仅丰富了我国丽赤壳属真菌的资源库，揭示了中国丽赤壳真菌丰富的多样性，还可为我国该属真菌引致病害的诊断和防控提供理论指导。.研究对33个菌株的DNA序列分析发现，已有5个基因中，CAL、TEF-1α和TUB2对丽赤壳属种类的鉴别能力较强，而三者中，TEF-1α和TUB2又较CAL更能有效的区分物种。进一步选取7个种进行全基因组测序，经基因组组装和基因预测，获得了7个种的全基因组序列。结合已有菌株HSMZH01，与丛赤壳科83个真菌基因组进行比较，获得丽赤壳属特异基因255个。该研究有助于分类体系的进一步完善。