香蕉染病植株的病原真菌分离及分子鉴定

Isolation and molecular identification of pathogenic fungi from infected Banana

香蕉枯萎病是一种毁灭性真菌病害,对香蕉的种植和产业发展危害严重,其病原为尖孢镰孢菌古巴专化型(Fusarium oxysporum f.sp.cubense)。为了研究该病原菌的致病机理和香蕉的枯萎病抗性机制,对病原菌进行分离。通过组织分离法,分离纯化真菌菌株,提取真菌DNA、PCR扩增ITS序列、测序及生物信息学分析等手段,对病原菌进行分子鉴定,确定引起香蕉枯萎病的致病菌。结果分离得到了8个真菌菌株,提取了各菌株的DNA;PCR扩增了8个菌株的ITS序列,并测序和生物信息学分析,根据8个菌株的ITS序列,进行了序列的多重比较分析,建立了各个菌株的分子进化树。通过形态观察、ITS序列的分析及病原接种致病实验,确认1、7、8号菌株为尖孢镰刀菌,能引起香蕉发生枯萎病症状,是香蕉枯萎病的致病真菌。

Fusarium wilt of banana is a destructive fungus disease caused by Fusarium oxysporum f.sp.cubense. This disease had harmful effects on banana planting and its industry development. In order to study the disease-causing mechanism of pathogen and the disease-resistant mechanism of banana, it was necessary to isolate and identify the pathogenic fungus. Tissue isolation method, DNA extraction, PCR amplification of ITS, sequencing and bioinformatic analysis were applied in this research. The results were as follow： eight fungi strains were isolated, and its DNA were extracted; ITS fragments of eight fungi strains were amplified and sequenced, a molecular phylogenic evolutionary tree was made base on ITS sequences. Based on morphological observation, ITS sequence analysis and banana inoculation experiment, the No. 1, No. 7 and No. 8 fungi strains were confirmed as the pathogenic fungi of banana wilt disease, it was Fusarium oxysporum f.sp.cubense.