Centre de Recherche en Innovation des Végétaux, Université Laval, Québec, G1V 0A6 Canada.
Agriculture and Agri-Food Canada, Brandon Research and Development Centre, Brandon, Manitoba, R7A 5Y3 Canada.
Plant Dis. 2021 Dec;105(12):4006-4013. doi: 10.1094/PDIS-04-21-0762-RE. Epub 2021 Nov 30.
The large-scale deployment of resistance to () genes in soybean has led to the rapid evolution of the virulence profile (pathotype) of . populations. Determining the pathotypes of . isolates is important in selecting soybean germplasm carrying the proper , but this process is fastidious and requires specific expertise. In this work, we used a molecular assay to assess the pathotypes of . isolates obtained throughout the provinces of Québec, Ontario, and Manitoba. In preliminary assays, the molecular tool showed equivalent prediction of the pathotypes as a phenotyping assay and proved to be much faster to apply while eliminating intermediate values. Upon analysis of nearly 300 isolates, 24 different pathotypes were detected in Québec and Ontario, compared with only eight in Manitoba, where soybean culture is more recent. Pathotypes 1a, 1c, and 1d was predominant in Québec, while 1a, 1b, 1c, 1d, and 1k pathotypes were the most common in Manitoba. Overall, the results showed that 98 and 86% of the isolates carried pathotype 1a or 1c, respectively, suggesting that and were no longer effective in Canada. Based on the history of soybean varieties used in surveyed fields, it was found that 84% of them contained genes that were no longer resistant against the pathotypes of the isolates found in the fields. While highlighting an easier and more precise option to assess pathotypes, this study presents the first pan-Canadian survey of . and stresses the importance of carefully managing the declining sources of resistance.
大豆中（）基因的大规模应用导致了大豆疫霉菌毒力谱（致病型）的快速进化。确定大豆疫霉菌分离株的致病型对于选择携带适当抗性的大豆种质至关重要，但这一过程繁琐，需要特定的专业知识。在这项工作中，我们使用分子测定法评估了在魁北克、安大略和马尼托巴省获得的大豆疫霉菌分离株的致病型。在初步试验中，该分子工具对致病型的预测与表型测定法相当，并且证明在消除中间值的同时，应用速度更快。在对近 300 个分离株进行分析后，在魁北克和安大略省检测到 24 种不同的致病型，而在马尼托巴省只有 8 种，因为那里的大豆种植时间较晚。1a、1c 和 1d 致病型在魁北克省占优势，而 1a、1b、1c、1d 和 1k 致病型在马尼托巴省更为常见。总体而言，结果表明，98%和 86%的分离株分别携带 1a 或 1c 致病型，表明和 不再在加拿大有效。根据调查田间使用的大豆品种历史，发现 84%的品种含有不再能抵抗田间分离株致病型的基因。虽然该研究强调了评估致病型的更简单、更精确的方法的重要性，但它首次对加拿大的大豆疫霉菌进行了全面调查，并强调了仔细管理抗性不断下降的来源的重要性。
