Characteristics of Pseudomonas syringae pv. mori, Causal Agent of Bacterial Blight of Mulberry (Morus Spp.) in Indonesia

Abstract

Pathogenic bacteria were consistently isolated from diseased leaves and twigs of mulberry. On leaves, water-soaked spots occurred firstly, which later changed into brown lesions. Leaf spots were irregularly shaped, and often surrounded by a yellow halo. On attached twigs, dark brown streaks developed, occassionally exuding bacterial ooze from the infected tissues. More than thirty isolates were collected from different mulberry areas in Indonesia. The bacteria were isolated by using standard dilution plating technique on King's medium B. Lopat tests indicated that mulberry isolates had the features of a fluorescent Pseudomonas sp. On the basis of carbon source utilization, pathogenicity tests and other features the pathogen has been tentatively identified as Pseudomonas syringae pv. mori.