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

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.