Identification of pathogen of leaf spots in Strelitzia reginae and its biological characteristics

The pathogen of leaf spots found in Strelitzia reginae was identified as Cylindrocladium colhounii peerall colhounii. Its hypha grew differently on different media. Richards medium was found the best. Conidia were not produced on Richards medium and PCA medium. The optimum temperature and pH value for hypha growth were 15-35℃ and 5.01-6.49. The optimum temperature for conidium growth was 25-35℃. Among 7 carbon sources, D-glucose, sucrose and amylum were better than maltose, D-fructose and lactose. Among 6 nitrogen sources, yeast extract, beef extract and ammonium nitrate were better than peptone, ammonium sulphate and Laspartic acid.