Diversity of tree-infecting Botryosphaeriales on native and non-native trees in South Africa and Namibia

Abstract

The Botryosphaeriales includes serious plant pathogens with a broad host and geographic distribution globally. In South Africa and Namibia, these fungi include important pathogens of native and non-native woody plants, and have consequently been studied extensively. Here we synthesize the information from the previous studies, particularly in the last decade, that report 62 species in the Botryosphaeriales from 66 hosts across South Africa and Namibia. Of these, 52 species have been reported from native hosts, 17 are from non-native hosts and twelve of these species occur on both native and non-native trees in the region.Much of the diversity of the Botryosphaeriales can be ascribed to native species that have fairly limited host and geographic ranges. Neofusicoccum parvum is amongst the most common species on both native and non-native hosts and it is thought to be native to the region. In contrast, Botryosphaeria dothidea, which is certainly an introduced species, is also widespread, and is very common on both native and non-native plants. Overall this synthesis underscores the growing understanding of the diversity of an important group of tree pathogens, their apparently common global spread as latent agents of disease, as well as their apparently common movement between commercial and native ecosystems.