The Population Structure Of Pathogen Of Eggplant Verticillium Wilt In Ya'an Mountain Area In Western Sichuan Province

Verticillium wilt has been a serious disease of eggplant around the world. The disease caused by Verticillium species reduces yield and the quality of eggplant. Verticillium wilt is also one of the three important diseases of eggplant in Sichuan. To determine population structure of Verticillium species causing wilt of eggplant, and to provide the scientific base for forecasting, controlling and resistance breeding, we conducted the research and collected eggplant samples showing symptoms of Verticillium wilt from 43 sample-collecting spots covering 5 Counties in Ya'n district.In this study, by performing culture isolation and single-spore isolation, 66 isolates of Verticillium, containing an isolate from cotton, were obtained. These isolates were then subjected to species identification, and studies on pathogenicity and vegetative compatibility were also conducted. The population structure of pathogen of eggplant Verticillium wilt was therefore disclosed in this research. The results of the research showed as follow:Isace and LI's methods were used in identifying .species of pathogen of eggplant Verticillium wilt according to several indexes, such as the ability of producing microsclerotial, growth rate planted on PDA at 25℃ and 30℃, color of conidiophore base in stems, and PCR amplification of genomic DNA as well. 66 isolates were able to produce microsclerotial, conidiophore of all the isoaltes was colorless with multi-whorled branches, each whorl contained 3 or 4 branchlets, and its growth was rather slow planted on PDA at 30℃ while fast at 25℃. A DNA fragment with a length of 140bp belonged to Verticillium dahliae was amplified with specific primers. As a result, all the 66 isolates were V. dahliae.Based upon origination of isolates and symptom of Verticillium wilt in field, 47 representative isolates along with 3 controls (JY2, JY3 and JY4) were used for differentiation test of pathogenicity, so as to unveil pathogenicity differentiation features in Ya'an. At the 3rd-leaf stage, eggplant seedlings were inoculated with pathogens of eggplant...