红花三叶草中产苦马豆素豆类丝核菌的分离与鉴定

为了确认中国红花三叶草中是否存在产苦马豆素（SW）的豆类丝核菌，用改良的真菌分离方法从植物样品中分离豆类丝核菌。根据豆类丝核菌的形态特征对分离的真菌进行初步筛选，然后对初步筛选所得真菌的5.8S rDNA ITS序列进行扩增、测序并构建系统发育树以确定初步筛选真菌的种属，经薄层色谱和气相色谱对豆类丝核菌菌丝体提取物进行SW检测。最终，筛选出一株符合豆类丝核菌形态特征的丝核菌属真菌RL2012，薄层色谱和气相色谱检测到其菌丝体提取物中含有SW。综上分析最终确认红花三叶草中存在产苦马豆素的豆类丝核菌。

Isolation and Identification of Swainsonine producing Rhizoctonia leguminicola from Red Clover

The study was to confirm whether red clover was infected by the swainsonine producing Rhizoctonia leguminicola in China. Rhizoctonia leguminicola was isolated from red clover by modified method. Firstly, Rhizoctonia leguminicola was screened by observing the morphology of the fungi. Secondly, the 5.8S rDNA ITS sequence of the screened fungi was amplified by PCR and sequenced, the phylogenetic tree was established based on the 5.8S rDNA ITS sequence. The species of screened fungi was identified by analyzing the phylogenetic tree. At last, swainsonine was detected in extraction of mycelium of Rhizoctonia leguminicola by TLC and GC. The results showed that a Rhizoctonia fungus RL202 which had morphological characteristics of Rhizoctonia leguminicola was isolated; swainsonine was found in the extraction of mycelium of RL2012 by TLC and GC. In summary we determined that the swainsonine producing Rhizoctonia leguminicola exist in the red clover.