Abstract Blackleg, caused by Leptosphaeria maculans, is a serious disease on canola or rapeseed in Canada, Australia and Europe. Disease levels have increased in western Canada recently and additional tools are needed to improve blackleg management. Seed treatment can be a cost-effective approach against blackleg, but there is currently no registered seed-treatment product targeting aboveground blackleg infection. In this study, a range of fungicides was evaluated for control of cotyledon infection by L. maculans and blackleg of canola. Under controlled environmental conditions, fluopyram showed greater efficacy than fluquinconazole (used against blackleg in Australia) in limiting cotyledon infection, while Prosper® EverGol and Helix® Vibrance (industry standards) were ineffective. Fluopyram at a rate of 30–150 g/100 kg seed generally inhibited cotyledon infection and this efficacy was not affected by delayed soil moisture for 3 weeks after planting. This indicates that the efficacy will unlikely be affected by a slight delay in germination due to a soil moisture deficit after seeding. In addition to typical mechanisms of succinate dehydrogenase inhibitor fungicides, fluopyram also induced expression of the indicator gene coding PR-1 proteins substantially, indicating the potential for inducing disease resistance. In field trials at 75 and 150 g/100 kg seed, fluopyram reduced the infection on cotyledons resulting from pricking inoculation on both susceptible and resistant canola cultivars, potentially limiting the infection into the stem. These seed treatment rates reduced the disease severity index (DSI) substantially on the susceptible cultivar, while DSI was low on a resistant cultivar with or without fluopyram treatment.

中文翻译：

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用杀真菌剂氟吡菌酰胺进行种子处理可限制黄斑钩端螺旋体对子叶的感染并减少油菜的黑脚病

摘要 黑腿病是由黄斑钩端螺旋体引起的，是加拿大、澳大利亚和欧洲油菜或油菜籽上的严重病害。最近加拿大西部的疾病水平有所增加，需要额外的工具来改善黑腿病管理。种子处理可能是一种具有成本效益的对抗黑腿病的方法，但目前没有针对地上黑腿病感染的注册种子处理产品。在这项研究中，评估了一系列杀菌剂用于控制 L. maculans 和油菜黑腿病的子叶感染。在受控环境条件下，氟吡菌酰胺在限制子叶感染方面表现出比氟喹康唑（在澳大利亚用于治疗黑脚病）更大的功效，而 Prosper® EverGol 和 Helix® Vibrance（行业标准）则无效。氟吡菌酰胺以 30-150 g/100 kg 种子的比例通常抑制子叶感染，并且这种功效不受种植后 3 周延迟土壤水分的影响。这表明，由于播种后土壤水分不足，发芽稍微延迟不太可能影响功效。除了琥珀酸脱氢酶抑制剂杀真菌剂的典型机制外，氟吡菌酰胺还大量诱导编码 PR-1 蛋白的指示基因表达，表明具有诱导抗病性的潜力。在 75 和 150 g/100 kg 种子的田间试验中，氟吡菌酰胺减少了对易感和抗性双低油菜品种进行针刺接种所导致的子叶感染，从而可能限制了对茎的感染。