Crown canker caused by Paramyrothecium roridum on greenhouse muskmelon (Cucumis melo) in China

A crown canker disease causing yellowing and wilting of the leaves was observed on muskmelon (Cucumis melo) plants in a number of greenhouses in Shouguang county, Shandong province, China, during April 2014 to July 2015, resulting in serious economic losses. Black sporodochia with white mycelial tufts emerged on surfaces of lesions at the base of the stem. Eleven fungal strains were isolated from infected tissues. On the basis of morphological features, ITS-5.8S rDNA and TEF1 sequence analysis, the isolates were identified as Paramyrothecium roridum (Tode) L. Lombard & Crous (syn. Myrothecium roridum Tode). The pathogenicity of the isolates was confirmed. The morphological characteristics of reisolated strains from inoculated muskmelon plants showing symptoms of crown canker were consistent with the original strains. A host range test indicated that strains had a wide range of hosts. To the best of our knowledge, this is the first report of muskmelon crown canker caused by P. roridum in China. Thi...