Pathogenic, genetic and molecular characterization and differentiation of races in Colletotrichum truncatum from lentil

由真菌病原体截形炭疽菌（Colletotrichum truncatum）引起的炭疽病是加拿大大草原中小扁豆的主要疾病，通过施用杀真菌剂、产量损失和由于质量差而导致的种子降级，控制炭疽病使小扁豆生产者花费大量资金。使用对这两个鉴定的小种具有抗性的品种被认为是控制该疾病的最经济和环境安全的方式。由于缺乏对田间真菌致病多样性的了解，病原体适应抗性品种的潜力，以及控制真菌对小扁豆中特定抗性基因的毒力的因素，阻碍了抗性育种的长期成功。使用已知的种族身份的隔离，我们将确定分子标记的毒力和使用这些来确定小扁豆领域的种族分布。为此目的收集的分离物也将用于分子种群研究，以确定真菌在自然界中是否是远系繁殖，从而可以通过有性重组发展新的种族。在两个小种杂交的后代群体的帮助下，我们将进行遗传研究，以确定该真菌毒力的遗传。将开发一个遗传连锁图谱的炭疽菌truncatum。我们还打算通过显微镜和分子工具研究两个种族对敏感和抗性扁豆基因型的感染生物学，以确定相互作用中的关键点，并确定病原体的毒力机制。在此过程中，我们将从受感染的扁豆叶片中开发一个cDNA文库，这将使我们能够鉴定病原体中与毒力有关的基因，以及将来与抗性有关的基因。靶基因的潜在功能将通过基因破坏突变体来确认。该项目的结果将使行业合作伙伴与植物育种家和病理学家一起制定长期战略，以发展对炭疽病的持久抗性，并在未来使用该项目开发的技术和研究工具以有效的方式监测病原体。

Anthracnose caused by the fungal pathogen Colletotrichum truncatum is a major disease of lentil in the Canadian Prairies, control of which is costing lentil producers a significant amount of money through fungicide applications, yield loss and downgrading of seed due to poor quality. Use of cultivars resistant to the two identified races is considered to be the most economical and environmentally safe way of controlling the disease. Long-term success in resistance breeding has been hampered by a lack of knowledge of the pathogenic diversity of the fungus in the field, the potential of the pathogen to adapt to resistant cultivars, and factors that govern virulence in the fungus to specific resistance genes(s) in lentil. Using isolates with known race identity, we will identify molecular markers for virulence and use those to determine the distribution of races in lentil fields. Isolates collected for that purpose will also be used for a molecular population study to determine whether the fungus is outbreeding in nature and thus could develop new races through sexual recombination. With the help of a progeny population from a cross of the two races, we will conduct a genetic study to determine inheritance of virulence in this fungus. A genetic linkage map for Colletrotrichum truncatum will be developed. We also intend to investigate the infection biology of the two races on susceptible and resistant lentil genotypes by microscopy and with molecular tools to identify critical points in the interaction, and to determine virulence mechanisms in the pathogen. In doing so we will develop a cDNA library from infected lentil leaves that will allow us to identify genes involved in virulence in the pathogen, and in future those involved in resistance. Potential function of targeted genes will be confirmed by gene-disrupted mutants. The results of this project will allow the industry partner, together with plant breeders and pathologists, to develop a long-term strategy for the development of durable resistance to anthracnose, and to monitor the pathogen in an efficient way in future using technology and research tools developed in this project.