我国烟草青枯菌的种下多样性及统一用名问题商榷

The Sequevar Diversity of Tobacco Bacterial Wilt Pathogen in China and Recommendation of the Standardized Nomenclature for It

烟草青枯病在我国许多烟区普遍发生,17个主要烟草种植区中有14个发生了青枯病,近年来,该病的危害范围有逐渐向北和冷凉地区扩展蔓延之势,造成了严重的经济损失.在传统分类中烟草青枯菌属于生理小种1号;在生化变种及演化型分类中,我国大多数烟草菌株为生化变种3(但也有部分为生化变种4),演化型Ⅰ,而美洲的烟草青枯菌则属于生化变种1,演化型Ⅱ;烟草青枯菌具有序列变种多样性,美洲菌株可聚类为序列变种7和25等,中国烟草青枯菌则属于序列变种13,14,15,17,34,44,54和55.学者们基于DNA-DNA杂交、基因组、蛋白质组及代谢组等证据提议将青枯菌这一复合种重新划分为3个新的种,即Ralstonia solanacearumsp.nov.(原本的演化型Ⅱ菌株),R.syzygii sp.nov.(原本的演化型IV菌株,包括苏门答腊病的病原及香蕉血液病细菌),R.pseudosolanacearumsp.nov.(原本的演化型Ⅰ和演化型Ⅲ菌株).基于此,美洲烟草青枯菌菌株为R.solanacearum,而我国的烟草青枯菌菌株为R.pseudosolanacearum,建议将我国烟草青枯病菌的中文名称为:假茄科雷尔氏菌.

Tobacco bacterial wilt occurs widely in tobacco-growing areas in China,in 14 of the 17 tobacco-growing provinces.In recent years,the disease has been spreading from the warm lowlands to the cool highlands or the north areas of China,resulting in great economic losses.Traditionally,the pathogen of Chinese tobacco bacterial wilt(Ralstonia solanacearum species complex)belongs to Race 1,Biovar 3(some are Biovar 4),Phylotype I,in taxonomy,while the pathogen of American and Brazilian tobacco bacterial wilt belongs to Race 1,Biovar 1,Phylotype II.This pathogen has sequevar diversity:American strains can be clustered into Sequevars 7 and 25,but Chinese strains belong to Sequevars 13,14,15,17,34,44,54 and 55.Based on the evidences obtained in DNA-DNA hybridization,genomic comparison,proteomic analysis and metabolic characterization,R.solanacearum species complex is reclassified into three new species:R.solanacearum sp.nov.(containing the original Phylotype Ⅱ strains),R.syzygii sp.nov.(including the original Phylotype Ⅳ strains,the pathogen of Sumatran disease and Banana Blood Disease Bacteria),and R.pseudosolanacearum sp.nov.(containing the original Phylotypes Ⅰ and Ⅲ strains).According to the new classification,the pathogen of tobacco bacterial wilt from Americas is R.solanacearum,and the strain of Chinese tobacco bacterial wilt is R.pseudosolanacearum.Therefore,the authors of this paper recommend that the strain of Chinese tobacco bacterial wilt be re-named R.pseudosolanacearum-假茄科雷尔氏菌in Chinese.