Coffee leaf rust, caused by the fungus Hemileia vastatrix, became a major concern for coffee-producing countries. Additionally, there is an increase in the resistance of certain races of the fungus to fungicides and breeding cultivars, making producers to use alternative control methods. In this work, we transplanted the leaf surface microbiota of rust-resistant coffee species (Coffea racemosa and Coffea stenophylla) to Coffea arabica and tested whether the new microbiota would be able to minimize the damage caused by H. vastatrix. It was seen that the transplant was successful in controlling rust, especially from C. stenophylla, but the protection depended on the concentration of the microbiota. Certain fungi such as Acrocalymma, Bipolaris, Didymella, Nigrospora, Setophaeosphaeria, Simplicillium, Stagonospora, Torula and bacteria such as Chryseobacterium, Sphingobium and especially Enterobacter and have their populations increased and may be related to the antagonism seen against H. vastatrix. Interestingly, relative population of bacteria from genera Pantoea, Methylobacterium and Sphingomonas decreased after transplant, suggesting a positive interaction between them and H. vastatrix development. Our findings may help to better understand the role of the microbiota in coffee leaf rust as well as help to optimize the development of biocontrol agents.

中文翻译：

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叶表面微生物群移植赋予易受影响的小粒咖啡抗咖啡叶锈病的能力

由真菌 Hemileia badatrix 引起的咖啡叶锈病成为咖啡生产国的一个主要问题。此外，某些真菌品种对杀菌剂和育种品种的抗性有所增加，使得生产者不得不使用替代控制方法。在这项工作中，我们将抗锈病咖啡品种（Coffea racemosa 和 Coffea stenophylla）的叶面微生物群移植到小粒咖啡中，并测试新的微生物群是否能够最大程度地减少 H. badatrix 造成的损害。结果表明，移植成功地控制了锈病，尤其是窄叶 C. stenophylla 的锈病，但这种保护作用取决于微生物群的浓度。某些真菌，例如 Acrocalymma、Bipolaris、Didymella、Nigrospora、Setophaeosphaeria、Simplicillium、Stagonospora、Torula 和细菌，例如 Chryseobacter、Sphingobium，尤其是 Enterobacter，其种群数量增加，可能与 H. badatrix 的拮抗作用有关。有趣的是，移植后泛菌属、甲基杆菌属和鞘氨醇单胞菌属的细菌相对数量减少，表明它们与 H.ivastatrix 的发育之间存在正相互作用。我们的研究结果可能有助于更好地了解微生物群在咖啡叶锈病中的作用，并有助于优化生物防治剂的开发。