Fernando W G Dilantha, Zhang Xuehua, Amarasinghe Chami C
Department of Plant Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
Plants (Basel). 2016 Mar 1;5(1):12. doi: 10.3390/plants5010012.
Blackleg, caused by Leptosphaeria maculans, is a major threat to canola production in Canada. With the exception of China, L. maculans is present in areas around the world where cruciferous crops are grown. The pathogen can cause trade barriers in international canola seed export due to its potential risk as a seed contaminant. The most recent example is China restricting canola seeds imported from Canada and Australia in 2009. Therefore, it is important to assess the level of Blackleg infection in Canadian canola seed lots and dockage (seeds and admixture). In this study, canola seed lots and dockage samples collected from Western Canada were tested for the presence of the aggressive L. maculans and the less aggressive L. biglobosa. Results showed that both L. maculans and L. biglobosa were present in seed lots and dockage samples, with L. biglobosa being predominant in infected seeds. Admixture separated from dockage had higher levels of L. maculans and L. biglobosa infection than samples from seed lots. Admixture appears to harbour higher levels of L. maculans infection compared to seeds and is more likely to be a major source of inoculum for the spread of the disease than infected seeds.
由大茎点菌引起的黑胫病是加拿大油菜籽生产的主要威胁。除中国外，大茎点菌存在于世界上种植十字花科作物的地区。由于该病原体作为种子污染物存在潜在风险，会导致国际油菜籽出口中的贸易壁垒。最近的例子是2009年中国限制从加拿大和澳大利亚进口油菜籽。因此，评估加拿大油菜籽批次和杂质（种子及混合物）中的黑胫病感染水平很重要。在本研究中，对从加拿大西部收集的油菜籽批次和杂质样本进行检测，以确定致病力强的大茎点菌和致病力较弱的双球大茎点菌的存在情况。结果表明，大茎点菌和双球大茎点菌均存在于种子批次和杂质样本中，双球大茎点菌在受感染种子中占主导地位。从杂质中分离出的混合物比种子批次样本的大茎点菌和双球大茎点菌感染水平更高。与种子相比，混合物似乎携带更高水平的大茎点菌感染，并且比受感染种子更有可能成为该病传播的主要接种源。
