Suppression of bacterial blight by a bacterial community isolated from theguttation fluids of anthuriums

Growth and survival of Xanthomonas campestris pv. dieffenbachiae in guttati on fluids (xylem sap exuded from leaf margins) of anthuriums were suppresse d by several bacterial strains indigenous to leaves of various anthurium cu ltivars Inhibition of growth was not observed in filter-sterilized guttatio n fluids and aas restored to original levels only by reintroducing specific mixtures of bacteria into filter-sterilized guttation fluids. The inhibito ry effect was related to the species in the bacterial community rather than to the total numbers of bacteria in the guttation fluids. One very effecti ve bacterial community consisted of five species isolated from inhibitory g uttation fluids of two susceptible anthurium cultivars. The individual stra ins in this community had no effect on the pathogen, but the mixture was in hibitory to X. campestris pv. dieffenbachiae in guttation fluids. The popul ations of the individual strains remained near the initial inoculum levels for at least 14 days. The effect of the five inhibitory strains on reducing disease in susceptible anthurium plants was tested by using a bioluminesce nt strain of X. campestris pv. dieffenbachiae to monitor the progression of disease in leaves nondestructively, Invasion of the pathogen through hydat hodes at leaf margins was reduced by applying the strain mixture to the lea ves. When the strain mixture was applied directly to wounds created on the leaf margins, the pathogen failed to invade through the wounds. This bacter ial community has potential for biological control of anthurium blight.