Evolution and biology of colletotrichum truncatum in Canada

真菌的性相容性和繁殖是多种多样的，从自我繁殖的生物体，不需要有性繁殖的伴侣，到其他具有高度复杂交配系统的群体。了解真菌的交配系统是了解这些生物作为生物物种的基础，它们交换遗传信息的潜力，它们的生态和进化。在子囊菌中，一组真菌包括许多重要的植物病原体，物种往往是自花受精，或需要一个不同的交配型（MAT）基因的配偶。这些基因通常有两种形式：MAT 1 -1和MAT 1 -2。具有这种交配系统的子囊菌真菌种群由两组组成，一组具有MAT 1 -1，另一组具有MAT 1 -2，并且需要其中的一个进行有性生殖。然而，并不是所有的子囊菌都有这个系统，包括截形炭疽菌，它是叶枯病或炭疽病的病原体，可以导致加拿大大草原上的主要作物扁豆产量损失高达70%。交配实验表明，这种真菌也需要遗传上不同的配偶进行交配，但所有分离株都有MAT 1 -2，没有一个有MAT 1 -1基因。该项目的第一个目标是通过进行交配实验和分析MAT 1 -2基因是否参与有性生殖来解开这种真菌交配的遗传控制。据报道，这种真菌中有两个种族，更具侵略性的种族似乎与两个性相容性群体之一有关。因此，另一个目标是找出交配和毒性之间是否确实存在联系。在实验室中诱导这种真菌进行有性繁殖很简单，但在扁豆田中还没有发现。相容的分离株出现在同一株植物上，因此在田间发生交配的可能性很高。然而，这种真菌的种群在遗传上非常相似，这就提出了这种真菌起源的问题。从国外引进受感染的小扁豆种子是一种选择，生活在一个或几个属于豆科植物的许多本地物种上，如小扁豆，另一种。所以第三个目的是阐明它在加拿大的起源。

Sexual compatibility and reproduction in fungi is varied and ranges from organisms that are self-fertile and do not require a partner for sexual reproduction, to other groups that have highly complicated mating systems. Understanding the mating system of fungi is fundamental to understanding these organisms as biological species, their potential to exchange genetic information, their ecology and evolution. Among the ascomycetes, a group of fungi including many important plant pathogens, species tend to be either self-fertile, or require a mate with a different mating type (MAT) gene. These genes typically have two forms: MAT1-1 and MAT1-2. Populations of ascomycetous fungi with this mating system consist of two groups, one with the MAT1-1 and the other with the MAT1-2, and it requires one of each for sexual reproduction. However, not all ascomycetes have this system, including Colletotrichum truncatum, causal agent of leaf blight or anthracnose that can cause yield losses of up to 70% on lentil, a major crop on the Canadian prairies . Mating experiments have shown that this fungus also requires genetically different partners for mating, but all isolates had the MAT1-2, and none had the MAT1-1 gene. The first objective of this project is to unravel the genetic control of mating in this fungus by conducting mating experiments and by analyzing whether the MAT1-2 gene is involved in sexual reproduction. Two races have been reported in this fungus, and the more aggressive race appears to be associated specifically with one of the two sexual compatibility groups. Hence another objective is to find out if there is indeed a connection between mating and virulence. Inducing this fungus to sexually reproduce in the laboratory is simple, but has not been seen in lentil fields. Compatible isolates occur on the same plant, so there is a high likelihood for mating to happen in the field. However, the population of this fungus is genetically very similar, and this raises the question of the origin of this fungus. Introduction on infected lentil seed from abroad is one option, living on one or several of the many native species belonging to the legume family like lentil, the other. So the third objective is to elucidate its origin in Canada.