海南桑树青枯病病原菌鉴定及其分子鉴定

Pathogen and Molecular Identification of Mubbery(Morus alba L.)Bacterial Wilt in Hainan

桑树青枯病是由青枯雷尔氏菌引起的细菌性病害,热带、亚热带地区发病严重,严重影响蚕桑产业的可持续发展。雷尔氏菌不同种间致病力和宿主各不相同,其防治策略也相应不同,准确地分离鉴定病原菌是青枯病有效防控的先决条件。本研究采集、分离了海南省琼中县桑青枯病发病桑园(‘桂桑优62’)桑树根部、茎部病原菌,并通过致病性、生理小种、生化变种测定,结合16SrDNA、特异性引物、复合PCR检测体系、序列变种等分子鉴定方法初步确定了病原菌的种类和分类地位。结果表明,引发海南省琼中县桑青枯病的病原菌属于青枯雷尔氏菌(Ralstonia solanacearum)、生理小种5(race 5)、生化变种Ⅴ(biovarⅤ),病原菌遗传进化分析结果显示病原菌属演化型Ⅰ(phylotypeⅠ)即亚洲分支菌株,序列变种12(sequevar 12)。这些结果将为海南桑青枯病的有效防控奠定基础。

Bacterial wilt of mulberry is a bacterial disease caused by Ralstonia solanacearum. It is serious in tropical and subtropical areas, which restricts the development of sericulture industry. The pathogenicity and host of R. solanacearum are different from each other, and the control strategy is also different. Accurate isolation and identification of the pathogen is the prerequisite for the effective control of bacterial wilt. In this study, we collected and isolated the pathogenic bacteria of mulberry(‘Guisangyou 62’) in Qiongzhong County, Hainan Province. The strains were selected and tested for pathogenicity, race and biovar, combined with 16 S rDNA molecular identification, specific primers, multiplex PCR detection system and sequence variation, and with phylogenetic analysis. All the three strains were R. solanacearum. According to the traditional classification the pathogen belongs to physiological race 5 and biovar V. The genetic evolution of the pathogen was further analyzed by molecular biology methods. The pathogen belonged to phylotype I(the Asiaticum division), sequevar 12. The results would lay a foundation for the effective control of mulberry bacterial wilt in Hainan.