Occurrence of bacterial brown stripe of creeping bentgrass on golf course green in Kyushu

A bacterial disease of creeping bentgrass (Agrostis stolonifera L.) was observed in golf course in Fukuoka Prefecture, Kyushu, Japan in 2000. It was characterized by brown stripes of the leaf sheaths. A non-fluorescent, aerobic, Gram-negative bacterium was consistently isolated from the infected plants. Infiltration of ten of the isolates into tobacco leaves resulted in a typical hypersensitive reaction. When creeping bentgrass plants were inoculated with the suspect isolates, typical bacterial brown stripe symptoms similar to those after natural infections were reproduced. The pathogen was reisolated from infected leaves two weeks after inoculation, thereby fulfilling the Koch's postulates. A sequence analysis of the genes coding for 16S rDNA revealed that the bacterium closely related to Acidovorax sp. On the basis of biochemical and physiological tests, the bacterium was identified as A. avenae subsp. avenae. The bacterium was pathogenic to Sorghum sudanense, S. vulgare, Zea mays, Avena sativa, Lolium multiflorum, Tricum aestivum, and Hordeum vulgare. It was only weakly pathogenic to Oryzae sativa and Panicům maximum. It was not pathogenic to P color atum, Astragalus sinicus, Desmodium intortum, Medicago sativa and Lotus cornicolatus. This is the first report of bacterial brown strip of creeping bentgrass caused by A. avenae subsp. avenae occurred in Kyusyu.