First Report of Pseudomonas cichorii Causing Bacterial Leaf Blight of Plumeria pudica in Hawaii

Abstract

Bridal Bouquet Plumeria (Plumeria pudica) is a commonly grown ornamental in Hawaii. In November 2014, a nursery grower located in Panaewa on the eastern side of Hawaii Island noticed water-soaked, irregular greyish-black leaf spots and leaf blight followed by defoliation on potted plants of P. pudica. Two leaf samples were submitted to the University of Hawaii Agricultural Diagnostic Service Center located at the Komohana Research and Extension Center in Hilo, HI for diagnosis. Isolations were made on King’s Medium B agar (KMB) and bacteria were consistently isolated from diseased tissue. Culture plates were forwarded to the USDA-ARS facility in Hilo, HI for further purification and molecular identification. Isolations on KMB resulted in essentially pure cultures that were non-mucoid, cream and fluorescent under 365 nm UV light. Four representative bacterial isolates were examined and characterized as gram-negative, oxidase positive, and produced a hypersensitive reaction in tobacco. Colonies were identif...