Brar G S, Kutcher H R
Crop Development Centre, Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada.
Plant Dis. 2016 Aug;100(8):1744-1753. doi: 10.1094/PDIS-12-15-1410-RE. Epub 2016 Jun 7.
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, has been common across Saskatchewan, Canada since 2000. Fifty-nine isolates of P. striiformis f. sp. tritici, the majority of which were collected between 2011 and 2013 from Saskatchewan and southern Alberta, were analyzed for virulence frequency and diversity and compared with isolates characterized in the Pacific Northwest and Great Plains regions of the United States. In all, 31 wheat differentials, including 20 near-isogenic lines and 1 triticale variety, differentiated 59 P. striiformis f. sp. tritici isolates into 33 races, of which one race, C-PST-1, represented 31% of the isolates. None of the races were virulent on Yr5, Yr15, or YrSP. Virulence frequency ranged from 65 to 98% on YrA, Yr2, Yr8, Yr9, Yr27, Yr29, Yr32, YrSu, 'Heines VII', and 'Nord Deprez'. Race C-PST-6 was virulent on the greatest number of the differentials (n = 25) and C-PST-18 on the fewest (n = 14). Discriminant analysis of principal components and multivariate cluster analyses detected three and four major groups, respectively, which differed from each other in terms of virulence spectrum and year of collection. The diversity of the P. striiformis f. sp. tritici population in southern Alberta was greater than in Saskatchewan, which indicated that, although P. striiformis f. sp. tritici is primarily windborne over great distances and does not usually overwinter, there are detectable differences in virulence between these regions of western Canada. Comparative analyses of virulence frequency of Saskatchewan or southern Alberta isolates with isolates representing races from the Great Plains and the Pacific Northwest of the United States indicated greater similarity of Saskatchewan races to the Great Plains despite strong correlations with both parts of the United States. This suggests that the P. striiformis f. sp. tritici population in Saskatchewan is a mixture of inoculum from both parts of the United States.
由条形柄锈菌小麦专化型（Puccinia striiformis f. sp. tritici）引起的小麦条锈病，自2000年以来在加拿大萨斯喀彻温省普遍发生。对59个条形柄锈菌小麦专化型分离株进行了毒力频率和多样性分析，其中大部分分离株于2011年至2013年从萨斯喀彻温省和艾伯塔省南部采集，并与美国太平洋西北地区和大平原地区鉴定的分离株进行了比较。总共31个小麦鉴别品种，包括20个近等基因系和1个小黑麦品种，将59个条形柄锈菌小麦专化型分离株区分为33个小种，其中一个小种C-PST-1占分离株的31%。没有一个小种对Yr5、Yr15或YrSP具有毒性。在YrA、Yr2、Yr8、Yr9、Yr27、Yr29、Yr32、YrSu、“Heines VII”和“Nord Deprez”上，毒力频率范围为65%至98%。小种C-PST-6对最多数量的鉴别品种（n = 25）具有毒性，而C-PST-18对最少数量的鉴别品种（n = 14）具有毒性。主成分判别分析和多变量聚类分析分别检测到三个和四个主要组，它们在毒力谱和采集年份方面彼此不同。艾伯塔省南部条形柄锈菌小麦专化型群体的多样性大于萨斯喀彻温省，这表明，尽管条形柄锈菌小麦专化型主要通过风力远距离传播且通常不能越冬，但加拿大西部这些地区之间在毒力方面存在可检测到的差异。将萨斯喀彻温省或艾伯塔省南部分离株的毒力频率与代表美国大平原和太平洋西北地区小种的分离株进行比较分析表明，尽管与美国两地都有很强的相关性，但萨斯喀彻温省小种与大平原地区的小种更相似。这表明萨斯喀彻温省的条形柄锈菌小麦专化型群体是来自美国两地接种体的混合物。
