Prosopidicola mexicana gen. et sp. nov., causing a new pod disease of Prosopis species

Abstract

Species of Prosopis introduced into South Africa from the Americas for fuel wood, shade and fodder, have become naturalized and widespread in the dry northwestern areas of this country. Invasive Prosopis species have been the target of a biological control programme in South Africa since 1985. During a survey for potential fungal biological control agents in Mexico and Texas in 2001, a pod disease was recorded on Prosopis glandulosa in both countries. The disease is characterized by black/grey pycnidia, flattening of the pods, and seed decay. Morphological investigations of the causal organism showed it to be a Coniothyrium-like, coelomycete. However, based on conidiogenous cell morphology and proliferation, we concluded that the organism is not congeneric with Coniothyrium s. str. Phylogenetic analysis of the SSU gene placed this fungus in the Diaporthales. Parsimony analysis of the ITS region (ITS-1, 5.8S, ITS-2) revealed it to group closely to Cryphonectria and Endothia. Consequently, a new genus, Prosopidicola, with type species Prosopidicola mexicana, is proposed