Identification of Muskmelon Gummy Stem Blight Pathogen and Its Biological Characters

Gummy stem blight is an important disease of muskmelon in the middle and later growth season.The affected stems of muskmelon were collected from some areas of Jiangsu province,China,and four strains of the pathogenic fungi isolated from the sample stems were investigated for the morphological and biological characters.The optimal temperature for the fungal growth was 25 ℃,and there were no significant effects of the pH value in the media on the growth of the pathogen.The rDNA-ITS genes of 4 isolates were amplified and sequenced.Based on the Blast search and the alignment analysis in GenBank database combined morphological characters,the pathogen of muskmelon gummy stem blight was identified as Didymella bryoniae(Auersw.) Rehm.,anamorph being Ascochyta citrullina Smith.