Disease Note.

First Report of Bacterial Gall of Wisteria sinensis Caused by Erwinia herbicola pv. milletiae in California.. D. C. Opgenorth, California Department of Food and Agriculture, Sacramento 95814. M. Hendson and E. Clark, University of California, Berkeley 94720. Plant Dis. 78:1217. Accepted for publication 21 September 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-1217C.

Three samples of Wisteria sinensis (Sims) Sweet with stem galls were submitted to the California Department of Food and Agriculture in 1993. Samples were collected from a single backyard plant with galls along the stem; numerous large galls (10-20 cm dia) initiated from spring pruning in an established planting; and container grown plants from a nursery. A yellow-pigment bacterium was consistently isolated from the galls on Miller-Schroth medium. Analysis using the BIOLOG system (BIOLOG Inc., Hayward, CA) identified the bacterial strains as Pantoea dispersa (74.6%). This species is included in the recently proposed name Pantoea agglomerans, which includes Enterobacter agglomerans, Erwinia herbicola, and Erwinia herbicola pv. milletiae. Nutritional characteristics of the strains isolated in California closely resemble those strains of E. herbicola pv. milletiae isolated from galls on Wisteria floribunda (Willd.) DC in Japan (2). Six strains of E. herbicola pv milletiae from California and fifty strains from Japan were inoculated onto W. sinensis and W. floribunda; all produced noticeable sellings of 4-5 mm in 14 days. The pathogen was consistently reisolated from gall tissue on inoculated plants. HPLC analysis (1) of culture supernatants from California and Japanese strains demonstrated that the plant growth regulator indoleacetic acid was produced by all strains. W. floribunda was previously considered as the only host of E. herbicola pv. milletiae (2).