Evolution and biology of colletotrichum truncatum in Canada

加拿大元宝炭疽病的进化和生物学

• 批准号: 261586-2011
• 负责人: Banniza, Sabine
• 金额: $ 1.97万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=547817
• 关键词: Evolution; biology; colletotrichum; truncatum; Canada

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.

真菌的性相容性和繁殖是多种多样的，范围从自体受精且不需要伴侣进行有性繁殖的生物体到具有高度复杂的交配系统的其他群体。了解真菌的交配系统对于理解这些生物体作为生物物种、它们交换遗传信息的潜力、它们的生态和进化至关重要。在子囊菌（包括许多重要植物病原体的一组真菌）中，物种往往要么自花受精，要么需要具有不同交配类型（MAT）基因的交配。这些基因通常有两种形式：MAT1-1 和 MAT1-2。具有这种交配系统的子囊菌真菌群体由两组组成，一组具有 MAT1-1，另一组具有 MAT1-2，并且有性繁殖需要每组中的一组。然而，并非所有子囊菌都具有该系统，包括元宝炭疽病（Colletotrichum truncatum），它是叶枯病或炭疽病的病原体，可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，这种真菌也需要基因上不同的伴侣进行交配，但所有分离株都具有 MAT1-2，并且没有一个具有 MAT1-1 基因。该项目的首要目标是通过进行交配实验并分析 MAT1-2 基因是否参与有性生殖，从而揭示这种真菌交配的遗传控制。据报道，这种真菌有两个种族，更具攻击性的种族似乎与两个性相容性群体之一特别相关。因此，另一个目标是查明交配和毒力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，但尚未在扁豆田中见到过。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，这种真菌的种群在基因上非常相似，这就提出了这种真菌的起源问题。一种选择是从国外引入受感染的扁豆种子，以属于豆科植物的一种或几种本地物种（如扁豆）为生。所以第三个目标是阐明其起源于加拿大。