Abstract Outbreaks of blossom blight in coriander (Coriandrum sativum) and caraway (Carum carvi) are common in western Canada, particularly when cool, wet conditions prevail during flowering, which can lead to total crop loss. Earlier attempts to identify the causal organisms were inconclusive, which has hampered blossom blight management and been a barrier for effective resistance breeding in these two crops. In order to address this knowledge gap, the pathogenicity of organisms isolated from coriander and caraway blossoms collected during blossom blight surveys in Saskatchewan in 2015 and 2016 was tested under controlled environment conditions. Isolates of Didymella cari, an undescribed fungus tentatively identified as a Heterosphaeria sp., Fusarium avenaceum, F. graminearum, Botrytis cinerea, as well as an isolate of Sclerotinia sclerotiorum obtained from the USA, were all shown to be pathogenic to coriander blossoms. An isolate of Septoria carvi was isolated from diseased caraway foliage and identified based on spore morphology, disease symptoms and sequence data. This is the first report of Septoria carvi in Canada. Isolates of Heterosphaeria sp. were shown to be pathogenic on caraway blossoms, whereas Septoria carvi and Aureobasidium pullulans failed to cause disease on caraway blossoms under the study conditions.

中文翻译：

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加拿大西部香菜和芫荽花的病原体

摘要 芫荽 (Coriandrum sativum) 和香菜 (Carum carvi) 的花枯病在加拿大西部很常见，尤其是在开花期间凉爽潮湿的条件下，这可能导致作物完全损失。早期识别致病生物的尝试尚无定论，这阻碍了花枯病管理，并成为这两种作物有效抗性育种的障碍。为了解决这一知识差距，在受控环境条件下测试了 2015 年和 2016 年在萨斯喀彻温省花枯病调查期间从香菜和葛缕子花中分离出的生物的致病性。Didymella cari 的分离物，一种未描述的真菌，暂时鉴定为 Heterosphaeria sp.，Fusarium avenaceum，F. graminearum，Botrytis cinerea，以及从美国获得的核盘菌分离物，均显示对香菜花具有致病性。从患病的葛缕子叶中分离出一种香芹菜分离物，并根据孢子形态、疾病症状和序列数据进行鉴定。这是Septoria carvi在加拿大的第一份报告。Heterosphaeria sp. 的分离物。被证明对香菜花具有致病性，而在研究条件下，香菜花和 Aureobasidium pullulans 未能在香菜花上引起疾病。