苦瓜枯萎病病原的鉴定及植株体内菌量测定

Identification and Determination of Fusarium Pathogen inside the Tissue of Momordica charantia

从福建省福州市的苦瓜枯萎病病株上分离到19个镰刀菌菌株,经Booth镰刀菌鉴定方法及尖孢镰刀菌特异性引物(FOF1/FOR1)PCR鉴定,确定19个菌株均为尖孢镰刀菌(Fusarium oxysporum)。将该菌株回接健康苦瓜幼苗,植株表现枯萎症状,重新分离又获得相同的病原物。采用分段取不同病株样本的方法研究了该菌在植株体内的数量分布,结果表明无症植株、中度病株和重度病株体内均存在尖孢镰刀菌,无症植株含菌量最低,中度病株含菌量最高,重度病株含菌量次之,但均表现为茎基部含菌量最高,根部次之,茎中部则低于根部,茎顶部和叶片均未分离到病原菌。

The objectives of this study were to isolate and identify the pathogen which caused wilt disease of Momordica charantia, and to determine the amount of this pathogen inside the plant. Plants showing wilt symptom were collected from Fuzhou, Fujian Province. Nineteen isolates of microorganism were isolated and identified as Fusarium oxysporum by Booths method and specific detection using primer FOF1/FOR1. The results of pathogenicity testing confirmed that these isolates were pathogen of M. charantia, through re-inoculated the young plants and re-isolated the pathogen. Meanwhile, comparative investigation was conducted on the amount of F. oxysporum inside the symptomatic and asymptomatic plants of M. charantia. It was found that the pathogen existing in both asymptomatic and symptomatic plants. The pathogens in the medium symptomatic plants were significantly more than those in the serious symptomatic and asymptomatic plants. The amounts of the pathogen in the bottom stems were higher than those in the roots, and no pathogen was found in the leaves and top stems.