广东火龙果果柄腐烂病病原菌的分离及鉴定

Isolation and identification of the pathogen causing fruit stalk rot of Hylocereus undatus in Guangdong

在广东省广州市从化区一火龙果种植基地发现了一种火龙果新病害,命名为火龙果果柄腐烂病。通过病原菌分离与纯化培养、柯赫氏法则验证、形态学观察和分子生物学鉴定,对引起火龙果果柄腐烂病的病原菌进行鉴定。病原菌菌落呈圆形,白色,大型分生孢子镰刀状,其形态特征与木贼镰刀菌(Fusarium equiseti)相似。病原菌接种后,火龙果果柄出现白色菌丝,与自然发病果实症状一致。病原菌的核糖体DNA内转录间隔区(rDNA-ITS)序列与已有木贼镰刀菌的rDNA-ITS序列同源性高达100%。结合形态学分析和rDNA-ITS基因序列鉴定结果,最终确定木贼镰刀菌(F.equiseti)为火龙果果柄腐烂病的病原菌。

Fruit stalk rot of dragon fruit（Hylocereus undatus） was found in one planting base in Conghua District,Guangzhou City,Guangdong Province. The pathogen was identified by isolation and purification,Koch’s postulate,morphological characteristic and sequence analysis. The colony of the pathogen was circular,white,and the shape of macroconidium was falciform. The morphology of the colony and spores were similar to Fusarium equiseti. The inoculated fruit showed the symptom of white mycelium,which was consistent with the symptom of natural occurrence disease in fruits. The rDNA-ITS sequence of the pathogen showed 100% identity to that of F. equiseti. Therefore,we concluded that the pathogen of fruit stalk rot on dragon fruit was F. equiseti,based on the morphological characteristics and the analysis of rDNA-ITS sequence.