Otero-Colina, G., Colegio de Postgraduados, Campus Montecillo, Montecillo, Edo. Mex., C.P. 56230, Mexico
Rodríguez-Alvarado, G., Laboratorio de Patología Vegetal, IIAF, Universidad Michoacana de San Nicolás de Hidalgo, Morelia-Zinapécuaro,Michoacán 58880, Mexico
Fernández-Pavía, S., Laboratorio de Patología Vegetal, IIAF, Universidad Michoacana de San Nicolás de Hidalgo, Morelia-Zinapécuaro,Michoacán 58880, Mexico
Maymon, M., Department of Plant Pathology and Weed Research, Agricultural Research Organization (ARO), Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Ploetz, R.C., Department of Plant Pathology, Tropical Research and Education Center, University of Florida, 18905 SW 280th Street, Homestead 33031-3314, United States
Aoki, T., NIAS Genebank (MAFF), National Institute of Agrobiological Sciences, 2-1-2, Kannondai, Tsukuba, Ibaraki 305-8602, Japan
ÓDonnell, K., Bacterial Foodborne Pathogens and Mycology Research Unit, United States Department of Agriculture-Agricultural Research Service-NCAUR, 1815 N. University St., Peoria, IL 61604, United States
Freeman, S., Department of Plant Pathology and Weed Research, Agricultural Research Organization (ARO), Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel

The primary objective of this study was to characterize Fusarium spp. associated with the economically devastating mango malformation disease (MMD) in Mexico. In all, 142 Fusarium strains were isolated from symptomatic mango inflorescences and vegetative tissues in eight geographically diverse Mexican states from 2002 through 2007. Initially, all the Mexican isolates were screened for genetic diversity using appolymerase chain reaction and random amplified polymorphic DNA markers and were grouped into seven distinct genotypes. Based on results of these analyses, evolutionary relationships and species limits of the genetically diverse MMD-associated Fusarium spp. were investigated using multilocus DNA sequence data and phylogenetic species recognition. Maximum parsimony analyses of a five-locus data set comprising 5.8 kb of aligned DNA sequence data indicated that at least nine phylogenetically distinct Fusarium spp. within the Gibberella fujikuroi species complex are associated with MMD, including one species within the African clade (Fusarium pseudocircinatum), two species within the Asian clade (F. mangiferae and F. proliferatum), and at least six species within the American clade (F. sterilihyphosum and five undescribed Fusarium spp.). Molecular phylogenetic analyses indicate that a novel genealogically exclusive lineage within the American clade was the predominant MMD associate in Mexico. This new Fusarium sp. caused MMD and could be distinguished from all other known species morphologically by the production of mostly sterile, coiled hyphae which are typically associated with sporodochial conidiophores together with unbranched or sparsely branched aerial conidiophores. Koch's postulates were completed for isolates of the new species on nucellar seedlings of mango cv. Ataulfo. This pathogen is formally described herein as F. mexicanum.