Late blight, caused by the oomycete Phytophthora infestans, is considered the most important and destructive disease of potato in Turkey. In this study, characterization of 367 isolates of P. infestans obtained from the potato‐growing areas of the country was carried out to evaluate the pathogen population structure over the 2017–2019 production seasons. The isolates were characterized by numerous features including mating type, in vitro mefenoxam sensitivity, simple‐sequence repeat (SSR) markers, and virulence against a set of potato differential lines. Most isolates were A2 mating type (353 isolates). Also, 68% of isolates were resistant to mefenoxam; the remainder were intermediate in their sensitivity and there were no sensitive isolates. SSR‐based genotypic analysis of P. infestans populations showed a low genetic diversity. The 13_A2 clonal lineage predominated with a frequency of 92.1%, followed by 34_A1 (3.3%) and 37_A2 (2.7%). Genotypes 34_A1 and 37_A2 were detected only in 2019. This is the first report of 34_A1 and 37_A2 clonal lineages causing late blight disease of potato in Turkey. The most abundant virulence type was one overcoming resistance genes R1, R2, R3, R4, R6, R7, R10, and R11. These results emphasized that the migration of individuals and the asexual generation of subclonal differences were the main factors driving the population structure of P. infestans in Turkey.

中文翻译：

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土耳其疫霉菌的种群结构显示优势克隆谱系和毒力的扩展和扩散

由卵菌疫霉疫霉引起的晚疫病被认为是土耳其马铃薯中最重要和最具破坏性的疾病。在本研究中，对从该国马铃薯种植区获得的367个无疫杆菌进行了鉴定，以评估2017-2019年生产季节的病原菌种群结构。分离株具有许多特征，包括交配类型，体外甲氧西am敏感性，简单序列重复（SSR）标记以及针对一组马铃薯差异系的毒力。大多数分离株是A2交配型（353个分离株）。另外，有68％的分离株对甲氧氟沙星有抗药性。其余的敏感性中等，没有敏感的分离株。基于SSR的基因型分析P. infestans种群显示出较低的遗传多样性。13_A2克隆谱系以92.1％的频率占主导地位，其次是34_A1（3.3％）和37_A2（2.7％）。基因型34_A1和37_A2仅在2019年被检测到。这是34_A1和37_A2克隆世系导致土耳其马铃薯晚疫病的首次报道。最丰富的毒力类型是一种克服抗性基因R1，R2，R3，R4，R6，R7，R10和R11。这些结果强调，个体的迁移和无性繁殖的亚克隆差异是驱动该种群结构的主要因素。P. infestans在土耳其。