Two New Species of Fusarium Section Liseola Associated with Mango Malformation

Abstract

AbstractMango malformation is an economically important disease of Mangifera indica globally. A recent DNA-based study indicated that two distinct, phylogenetic lineages previously identified as Fusarium subglutinans are associated with this disease in South Africa. The objective of this study was to characterize Fusarium isolates associated with mango malformation, including the two different F. subglutinans groups, based on morphological characteristics. For this purpose we examined Fusarium strains isolated from diseased mango inflorescences from diverse geographical origins. We also used sexual compatibility tests to determine whether sexual reproduction among the strains was possible. The morphological characters considered were shape of the conidia, presence of mono- and/or polyphialides, origin of the conidiophores from the substrate, presence of chlamydospores and the presence of sterile coiled hyphae. Three unique Fusarium spp. were identified. In this paper, we provide formal descriptions for the two new taxa in the section Liseola that we have named F. mangiferae and F. sterilihyphosum. Fusarium mangiferae is conspecific with strains that were previously identified as F. subglutinans and reported to be the causal agent of malformation in mango growing areas throughout the world. Fusarium sterilihyphosum, on the other hand, has been isolated only from malformed mango tissue in South Africa.KeywordsGibberella fujikuroi complexmangotaxonomy We thank the National Research Foundation (NRF) and members of the Tree Pathology Co-operative Programme (TPCP) for financial support. We are grateful to Dr. John F. Leslie for supplying Fusarium isolates from mango malformation in Malaysia and Egypt, Dr. Randy Ploetz for supplying Fusarium isolates from mango malformation in Florida, and Dr. S. Freeman for supplying Fusarium isolates from mango malformation in Israel. We also appreciate the suggestions of two anonymous reviewers and the associate editor that were useful in improving our manuscript.