Description of a new disease on Erythrina sp. in Martinique (French West Indies) and preliminary characterization of the causal agent as a novel Erwinia species

In spring 1995, symptoms of partial defoliation were observed an Erythrina indica var. fastigiata trees, commonly used as windbreaks in banana plantat ions in Martinique (French West Indies). Browning of the bark surface was c onsistently observed at the base of defoliated branches. Bacteria were isol ated as nearly pure cultures from typical necrotic lesions an the bark. Res ults of Gram stain, staining of flagella and biochemical tests indicated th at all isolates belonged to the Enterobacteriaceae, and to the genus Erwini a. Numerical analysis of the results of 48 biochemical properties showed th at Erwinia isolates from diseased erythrina trees constituted a homogenous phenotypic cluster, and that, although weakly pectolytic, these isolates we re closely related to pectolytic Erwinia species: E. carotovora ssp. betava sculorum and ssp. wasabiae, and E, cacticida. However, they could be clearl y distinguished by different biochemical characteristics from type strains of known plant pathogenic species of Erwinia, Pantoea and Enterobacter. Und er greenhouse conditions, the isolates were pathogenic to Erythrina indica var. fastigiata cuttings, but not to banana and pineapple, which are major crops in Martinique.