First Report Ofquambalaria Eucalyptiin Youngeucalyptusplants In Field Conditions In Brazil

The genusQuambalariaincludes several important pathogens ofEucalyptusandCorymbiaspp., mainly those that cause leaf and shoot blight. The speciesQuambalaria eucalyptihas been reported to be an aetiological agent of this disease in Brazil only in nurseries involved in the production ofEucalyptusminicuttings, where climatic conditions are more favourable for the pathogen. The aim of this study was to identify the pathogen that causes a similar disease in youngEucalyptustrees. For this, we used morphological characteristics, pathogenicity tests and DNA sequence data. Sequences of five isolates obtained from leaves and cankers were compared to 21 (Twenty five isolates of Quambalaria spp. and one outgroup) sequences deposited in GenBank. Twenty six isolates were subjected to multilocus analyses of internal transcribed spacer (ITS) and rDNA large subunit (LSU) sequence information. The resulting consensus tree showed that isolates in this study could be grouped withQ. eucalyptiinto one distinct clade, and the morphological characteristics were similar to those described in the literature. The pathogenicity was confirmed, and the pathogen was re-isolated from inoculated plants, confirming Koch's postulates. This is the first record ofQ. eucalypticausing leaf and shoot blight on youngEucalyptusplants in field conditions in Brazil. The presence of this disease in nurseries and its occurrence in the field is cause for alarm inEucalyptusbreeding programmes in Brazil.