Departamento de Protección Vegetal, Facultad de Agronomía, Universidad de la República, Paysandu, Uruguay.
Fungal Biol. 2013 Feb;117(2):94-102. doi: 10.1016/j.funbio.2012.12.002. Epub 2012 Dec 21.
Mycosphaerella species are well-known causal agents of leaf diseases on many economically and ecologically important plant species. In Uruguay, a relatively large number of Mycosphaerellaceae and Teratosphaeriaceae are found on Eucalyptus, but nothing is known of these fungi on native Myrtaceae. The aim of this study was to identify Mycosphaerellaceae and Teratosphaeriaceae species associated with leaf diseases on native Myrtaceae in Uruguay and to consider whether host jumps by the pathogen from introduced Eucalyptus to native Myrtaceae have occurred. Several native forests throughout the country were surveyed with special attention given to those located close to Eucalyptus plantations. Five species belonging to the Mycosphaerellaceae and Teratosphaeriaceae clades were found on native Myrtaceous trees and three of these had previously been reported on Eucalyptus in Uruguay. Those occurring both on Eucalyptus and native Myrtaceae included Pallidocercospora heimii, Pseudocercospora norchiensis, and Teratosphaeria aurantia. In addition, Mycosphaerella yunnanensis, a species known to occur on Eucalyptus but not previously recorded in Uruguay, was found on leaves of two native Myrtaceous hosts. Because most of these species occur on Eucalyptus in countries other than Uruguay, it appears that they were introduced in this country and have adapted to be able to infect native Myrtaceae. These apparent host jumps have the potential to result in serious disease problems and they should be carefully monitored.
球腔菌属物种是许多经济和生态上重要植物物种叶片病害的已知致病因子。在乌拉圭，桉树的叶部病害上存在相对数量较多的球腔菌科和突脐孢科真菌，但对当地桃金娘科植物上的这些真菌却知之甚少。本研究的目的是鉴定与乌拉圭本地桃金娘科植物叶片病害相关的球腔菌科和突脐孢科真菌，并考虑病原体是否从引入的桉树跳跃到本地桃金娘科植物。对全国各地的几个原生林进行了调查，特别关注那些靠近桉树种植园的原生林。在本地桃金娘科树上发现了属于球腔菌科和突脐孢科的五个物种，其中三个以前在乌拉圭的桉树中报道过。既在桉树又在本地桃金娘科植物上发生的包括苍白尾孢、假尾孢和橘色突脐孢。此外，以前在乌拉圭未见报道，但已知在桉树发生的云南球腔菌，也在两个本地桃金娘科植物的叶片上发现。由于这些物种中的大多数在乌拉圭以外的国家都发生在桉树上，因此它们似乎是被引入该国的，并已适应能够感染本地桃金娘科植物。这些明显的寄主跳跃有可能导致严重的疾病问题，应仔细监测。
