Maria A. Ferreira,
Thomas C. Harrington,
Acelino C. Alfenas, and
Eduardo S. G. Mizubuti
First, third, and fourth authors: Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil; and second author: Department of Plant Pathology, Iowa State University, Ames 50011.
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Accepted for publication 5 April 2011.
Ceratocystis wilt on eucalyptus, caused by Ceratocystis fimbriata, was first recognized in 1997 in the state of Bahia, Brazil, but is now known in five other states and in four other countries. C. fimbriata is a native, soilborne pathogen in some parts of Brazil but we hypothesized that genotypes of the pathogen have been moved among plantations in rooted cuttings collected from diseased trees and within plantations on cutting tools. We used six microsatellite markers to identify 78 genotypes of C. fimbriata among 177 isolates from individual trees in 20 eucalyptus plantations. The highest gene and genotypic diversity values were found in plantations on formerly wild Cerrado forest in Minas Gerais, suggesting that the fungus was in the soil prior to planting eucalyptus. In contrast, one or only a few genotypes were found in plantations on previous pastureland (with no woody hosts) in Bahia and São Paulo, and most of these genotypes were found in a Bahian nursery or in one of two Bahian plantations that were sources for rooted cuttings. Sources of cuttings tended to be dominated by one or a few genotypes that may have been spread within the plantation on cutting tools.
© 2011 The American Phytopathological Society