本研究尝试采用国际上新兴的青枯菌演化型分类框架并结合传统的生化变种鉴定方法,旨在探究福建省烟草青枯病菌系的构成,从而揭示青枯病的流行规律,为指导烟草青枯病的抗病育种提供理论依据。2008~2009年,分别于福建省南平、三明以及龙岩地区田间烟草病株上分离获得了45个烟草青枯病菌株。经青枯菌演化型复合PCR检测,45个菌株均能够扩增得到片段大小分别为144 bp和280 bp的两条特异性扩增条带,从而表明全部分离菌株均系青枯菌演化型I型即亚洲分支菌株。继而基于45个分离菌株对3种双糖和3种己醇氧化利用能力的检测结果,鉴定出其中43个菌株属于青枯菌生化变种III,1个菌株属于生化变种IV,1个菌株属于非标准型生化变种(能利用山梨醇和甜醇,不能利用3种双糖和甘露醇)。该研究结果部分揭示了造成国外引进的烟草品种青枯病抗性水平下降或丧失的可能原因。
Rising phylotype identification system and traditional biovar determination method was combined to determine the structure of tobacco Ralstonia solanacearum strains from Fujian province and the epidemic pattern so as to provide theoretic guidance to disease-resistant breeding.45 Ralstonia solanacearum strains,isolated from wilted tobacco plants in Sanming,Nanping,and Longyan region of southeast China's Fujian province,were collected from 2008 to 2009.Phylotype specific multiplex PCR(Pmx-PCR) revealed that all 45 isolates,producing both 144 bp and 280 bp amplicons,belonged to R.solanacearum phylotype I(the Asiaticum division).Furthermore,on the basis of the ability of isolated strains to oxidize three hexose(lactose,maltose and cellobiose) and three disaccharides(mannitol,sorbitol and dulcite),43 strains were identified as biovar III,1 as biovar IV,and 1 as atypical biovar on account of the ability to utilize sorbitol and dulcite.The results explained the possible reason why tobacco cultivars introduced from abroad lost their resistance or showed lower resistant level to bacterial wilt.