周口地区油菜核盘菌分离鉴定及侵染分析

从河南省周口市采集感染菌核病的油菜,对菌核进行分离和鉴定.采用单孢分离法分离得到1个单菌系,对该单菌系进行了菌落和显微形态分析,初步鉴定该菌系为Sclerotinia sclerotiorum.利用真菌通用引物ITS1和ITS4对所分离的单菌系内转录间隔区(inter transcribed spacer,ITS)进行PCR扩增,得到540bp大小的片段,经过克隆测序和在GenBank中进行BLASTn分析,发现与部分S.sclerotiorum的ITS序列同源性达到100%,进一步鉴定该分离菌株为S.sclerotiorum.进化树分析显示,该菌系与来自意大利、日本及我国武汉地区的菌系聚为一支,说明周口菌系来源广泛.对该菌系侵染油菜叶片的细胞学和组织化学分析表明,该菌系对耐病和感病油菜品种的细胞反应相似,都没有H2O2积累,差别主要表现在耐病油菜上菌丝长度较短.

Identification of Sclerotinia sclerotiorum on Oilseed Rape in Zhoukou and Analysis of Its Infection on Plants

With the method of single-spore isolation an fstrain of Sclerotinia sclerotiorum was isolated from oilseed rape(Brassica napus)in Zhoukou city of Henan province,The morphology and microscopic analysis indicated that the isolated stain was S.sclerotiorum.Universal PCR primers ITS1and ITS4for fungi were used to amplify the internal transcribed spacer(ITS)of the isolated strain,which resulted in PCR fragment with 540bp.The PCR product was sequenced and analyzed by using BLASTn,which showed 100%homology to ITS sequences of some S.sclerotiorumstains.It further proved that the isolated strain was S.sclerotiorum.Phylogenetic tree analysis demonstrated that the isolated strain of S.sclerotiorum in Zhoukou was close to stains from Italy,Japan and Wuhan of China,suggesting that the origin of S.sclerotiorumin Zhoukou may be diverse.