炭疽病,受Colletotrichumsublineola的煽动,是高粱最具破坏性的叶面病,在恶劣条件下,易感品种的产量损失可能超过80%。尽管存在几种抗性来源,但病原体的高度可变性质使其管理具有挑战性。在这项研究中,140株C.sublineola分离株的遗传变异性和致病性,使用限制性位点相关测序(RAD-Seq)进行测序,导致1244个质量SNP。基于SNP数据的遗传关系显示出基于分离株起源的低至高遗传多样性。来自佐治亚州和北卡罗来纳州的分离株被分为多个簇,彼此之间具有一定程度的遗传关系。即使一些来自德克萨斯州的分离株形成了一个集群,其他人聚集在波多黎各的分离株中。波多黎各的分离株分布分散,表明这些分离株的多样性。种群结构和聚类分析显示,遗传变异分为八个种群和一个混合组。在18个高粱差异品系上的30个测序分离株的毒力模式揭示了27个新的致病型。SC748-5、SC112-14和Brandes对所有测试的分离株都有抗性,而BTx623易感。品系TAM428易感所有的病理类型,除了病理型26。未来使用本研究中采用的18个差异,其中包含在美洲使用的品种/品系,亚洲,非洲,可以在全球范围内更好地表征C.sublineola致病型,从而加速了对炭疽病病原体具有稳定抗性的高粱系的发展。
Anthracnose, incited by Colletotrichum sublineola, is the most destructive foliar disease of sorghum and, under severe conditions, yield losses can exceed 80% on susceptible cultivars. The hyper-variable nature of the pathogen makes its management challenging despite the occurrence of several resistant sources. In this study, the genetic variability and pathogenicity of 140 isolates of C. sublineola, which were sequenced using restriction site-associated sequencing (RAD-Seq), resulted in 1244 quality SNPs. The genetic relationship based on the SNP data showed low to high genetic diversity based on isolates\' origin. Isolates from Georgia and North Carolina were grouped into multiple clusters with some level of genetic relationships to each other. Even though some isolates from Texas formed a cluster, others clustered with isolates from Puerto Rico. The isolates from Puerto Rico showed scattered distribution, indicating the diverse nature of these isolates. A population structure and cluster analysis revealed that the genetic variation was stratified into eight populations and one admixture group. The virulence pattern of 30 sequenced isolates on 18 sorghum differential lines revealed 27 new pathotypes. SC748-5, SC112-14, and Brandes were resistant to all the tested isolates, while BTx623 was susceptible to all. Line TAM428 was susceptible to all the pathotypes, except for pathotype 26. Future use of the 18 differentials employed in this study, which contains cultivars/lines which have been used in the Americas, Asia, and Africa, could allow for better characterization of C. sublineola pathotypes at a global level, thus accelerating the development of sorghum lines with stable resistance to the anthracnose pathogen.