Neonectria ditissima , the causal agent of European Canker and Neonectria fruit rot, is a quarantine apple pathogen in Brazil, restricted to some production areas of Rio Grande do Sul, Santa Catarina, and Paraná states. The quarantine rests on a product certification based on the absence of symptoms but it is not known whether the pathogen could be moving around in quiescent infections. In this work, we detected N. ditissima after incubation of asymptomatic commercial fruit. The identity of the pathogen was confirmed using morphological and molecular tools, and Koch’s postulates were fulfilled on “Gala” apples. We demonstrated that fruits are weak links in quarantine efforts. Fruit stored at low temperatures present quiescent N. ditissima infections, which may develop rapidly with abundant sporulation when exposed to more suitable conditions, as those of commercialization. Revised management strategies for flower and fruit treatment, as well as studies on efficient detection methods are strongly recommended.

中文翻译：

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巴西商品苹果果实中 Neonectria ditissima 静息侵染的检测与表征

Neonectria ditissima 是欧洲溃疡病和 Neonectria 果实腐烂的病原体，是巴西的一种检疫性苹果病原体，仅限于南里奥格兰德州、圣卡塔琳娜州和巴拉那州的一些产区。隔离取决于基于没有症状的产品认证，但尚不清楚病原体是否会在静止感染中四处移动。在这项工作中，我们在无症状的商业水果孵化后检测到了 N. ditissima。使用形态学和分子工具确认了病原体的身份，科赫的假设在“嘎啦”苹果上得到了满足。我们证明了水果是检疫工作中的薄弱环节。在低温下储存的果实会出现静止的 N. ditissima 感染，当暴露在更合适的条件下时，这种感染可能会迅速发展并形成大量孢子，作为商业化的那些。强烈建议修订花卉和果实处理的管理策略，以及研究有效的检测方法。