海南槟榔细菌性叶斑病病原鉴定

Identification of the bacterial leaf spot pathogen of betel palm in Hainan Province

槟榔（ArecacatechuL．）属棕榈科常绿乔木，是我国四大南药之一，具有固齿杀菌、消化积食、驱虫等功效。槟榔还是世界著名的三大口腔嗜物之一，为我国海南及湖南等部分地区群众所喜好。目前，海南省槟榔年产值超过30亿元．已发展为仅次于橡胶的第二大热带作物．是琼海、屯昌等地200多万农民的主要经济来源之一。

In 2008, a severe bacterial disease was observed in Wenchang, Hainan Province. Symptoms consis- ted of small circular to elongated brown lesions surrounded by yellow halos. All isolates, which formed white colonies, were gram-negative and each had a single, polar, sheathed flagellum. Isolates were oxidase and cata- lase positive, negative for arginine dihydrolase, gelatin hydrolysis and starch hydrolysis, and acid production from levan. Sequences of the 16S rDNA gene of the isolates shared 98% sequence identity with that of Burkhold- eria andropogonis strain LMG2129 （GenBank accession No. NR118985）. Pathogenicity tests were conducted and fulfilled Koch＇s postulates, indicating that these isolates are causative agent of the disease. The results led to the conclusion that the causal pathogen of betel palm bacterial leaf spot was B. andropogonis. It is the first report of B. andropogonis causing bacterial leaf spot of betel palm in China's Mainland.