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 on #Erythrina indica# var. #fastigiata# trees, commonly used as windbreaks in banana plantations in Martinique (French West Indies). Browning of the bark surface was consistently observed at the base of defoliated branches. Bacteria were isolated as nearly pure cultures from typical necrotic lesions on the bark. Results of Gram stain, staining of flagella and biochemical tests indicated that all isolates belonged to the #Enterobacteriaceae#, and to the genus #Erwinia#. Numerical analysis of the results of 48 biochemical properties showed that #Erwinia# isolates from diseased erythrina trees constituted a homogenous phenotypic cluster, and that, although weakly pectolytic, these isolates were closely related to pectolytic #Erwinia# species : #E. carotovora# ssp. #betavasculorum# and ssp. #wasabiae#, and #E. cacticida#. However, they could be clearly distinguished by different biochemical characteristics from type strains of known plant pathogenic species of #Erwinia#, #Pantoea# and #Enterobacter#. Under greenhouse conditions, the isolates were pathogenic to #Erythrina indica# var. #fastigiata# cuttings, but not to banana and pineapple, which are major crops in Martinique. (Résumé d'auteur