Phylogeny of some cercosporoid fungi from Citrus
This study examines several cercosporoid species that are known to cause foliar diseases of Citrus. A cercosporoid fungus causing a new fruit and leaf spot disease on Citrus in South Africa was identified. From morphological and rDNA sequence data (ITS1, 5.8S and ITS2), it was concluded that the new disease was caused by Cercospora penzigii, belonging to the Cercospora apii species complex. It was subsequently compared with a similar organism, Pseudophaeoramularia angolensis, which is of quarantine significance to the citrus industry. The genus Pseudophaeoramularia is regarded as synonym of Pseudocercospora, and subsequently a new combination is proposed in Pseudocercospora as P. angolensis. Cercospora gigantea was shown to not represent a species of Cercospora, while Mycosphaerella citri was found to be morphologically variable, suggesting that it could represent more than one taxon. A key is also provided to the cercosporoid species occurring on Citrus.