甘肃大葱贮藏期镰孢菌腐烂病病原鉴定

【目的】大葱在贮藏期频繁发生镰孢菌腐烂病,损失严重。明确该病害病原种类对病害防治具有重要意义。【方法】利用组织分离法对采集自甘肃省兰州市(区)蔬菜市场的16份大葱贮藏期镰孢菌腐烂病病样进行病原物的分离、纯化培养,经单孢分离后根据形态学特征,再结合r DNA-ITS、EF-1a(tef)基因序列分析的方法进行鉴定。【结果】共分离得到80株镰孢菌,经鉴定分属3个种,即层出镰孢菌(Fusarium proliferatum)、尖孢镰孢菌(F.oxysporum)和燕麦镰孢菌(F.avenaceum),其中层出镰孢菌为大葱镰孢菌腐烂病的优势致病菌,分离频率为52.50%。对兰州白葱不同部位进行致病性测定,结果表明层出镰孢菌对大葱鳞茎的致病力最强,而燕麦镰孢菌对大葱鳞茎的致病力最弱。【结论】3种镰孢菌作为该病害的病原,属国内首次报道。

Identification of pathogens causing shallot storage Fusarium rot disease in Gansu province, China

Objective] Shallot Fusarium rot disease occurred constantly during storage. It was important for controlling the disease to confirm the pathogenic Fusarium species of the disease. Methods] The pathogens of shallot storage Fusarium rot disease were isolated and cultured purely by tissue isolation method from 16 samples collected from Lanzhou markets in Gansu province, China. The generated Fusarium strains were identified by morphological characteristics and analysis of rDNA-ITS, EF-1a(tef) gene sequences after single spore isolation. Results] The generated 80 Fusarium strains belonged to three species including F. proliferatum, F. oxysporum and F. avenaceum. F. proliferatum with 52.50 percentage isolation frequencies was the dominant pathogen of shallot Fusarium rot disease. The pathogenicity test showed that the pathogenicity of F. proliferatum was the strongest in shallot bulbs among the three Fusarium species, F. avenaceum was the weakest. Conclusion] Three pathogenic Fusarium species were firstly reported as the pathogens of shallot storage Fusarium rot disease in Ganshu province, China.