Pathogen Identification Causing Verticillium Wilt on Chinese Cabbage in Beijing Area

The pathogen causing verticillium wilt on Chinese cabbage in Beijing area was identified by morphological characteristics,pathogenicity test,and the sequence of ribosomal DNA-ITS in this study. Four isolates from diseased plants of four different varieties were obtained. Seedlings showed symptoms of yellowing,wilting of leaves,discoloration in vascular tissue of the stem and death after inoculating with isolates,which were consistent with the symptoms in the field. The fungus showed dark colonies that produced verticillate conidiophores with two to three layers with colorless,ovoid,conidia and small,black microsclerotia on PDA medium. When cultured under the temperature ranged from 14 ℃ to 32 ℃,hyphae showed fastest growth at 22 ℃;The rDNA-ITS sequence of the fungi which was 100% identity of the four isolates has been submitted to GenBank(GenBank accession number:JN564038).