Abstract: The symptoms of plant wilt were found in the regional planting test of Musa ×paradisiaca ‘Tiancheng No. 1’, which is a new banana variety developed through space breeding using ‘Baxijiao’. In this study, samples were taken from the typical plants of ‘Tiancheng No. 1’ with fusarium wilt. The pathogenic fungus was isolated and purified by tissue isolation method, and then the pathogenicity test was conducted by inoculating the roots of ‘Tiancheng No.1’ seedlings. At the same time, the pathogen were identified by combining morphological characteristics and rDNA-ITS sequence detection. The results showed that the pathogenic strain LWZ-XJ-4 was identified as F. oxysporum according to its morphological characteristics. The phylogenetic tree based on rDNA-ITS sequence showed that the pathogen closed to physiological race 4 of F. oxysporum Cuban specialization. The study identified the type of pathogen causing the wilt of banana ‘Tiancheng No. 1’. The results were suggestive to the control of the fusarium wilt and the promotion of ‘Tiancheng No. 1’.

Key words: fusarium wilt of banana, Fusarium oxysporum f. sp. cubense, morphological characteristics, ITS sequence

摘要： ‘天成1号’香蕉Musa ×paradisiaca ‘Tiancheng No. 1’是利用‘巴西蕉’通过航天育种选育的香蕉新品种，在区域种植试验中出现植株枯萎症状。取其枯萎病植株组织，经分离、纯化、培养病原菌，并将病原菌灌根回接蕉苗进行致病性测定，同时结合形态学特征和rDNA-ITS序列检测的方法鉴定病原菌类型。根据形态特征鉴定‘天成1号’枯萎病病原菌株LWZ-XJ-4为尖孢镰刀菌，基于rDNA-ITS序列构建的系统发育树显示该病原菌与尖孢镰刀菌古巴专化型4号生理小种进化距离最近。研究结果明确了引起太空香蕉‘天成1号’枯萎病的病原菌类型，对该香蕉品种枯萎病防控及推广种植有重要意义。

关键词: 香蕉枯萎病, 尖孢镰刀菌古巴专化型, 形态特征, ITS序列