수박 品種의 國內外 덩굴쪼김병 分離菌株에 대한 抵抗性 反應

Reaction of watermelon collections to domestic and alien isolates of fusarium oxysporum f. sp. niveum

Thirty two cultivars and inbred lines of watermelon were inoculated with one domestic and alien isolates to investigate their desease rates and resistance for Fusarium oxysporum f. sp. niveum. The disease rate of tested cultivars and inbred lines for domestic isolate of F. oxysporum f. sp. niveum showed wide range of resistance from less than 20% high resistance to 100% of susceptibility. As results of dipping method for screening using 1×10⁸ cell/㎖ inoculum, two inbred lines showed high resistance and 14 varieties showed moderate one. By the difference of agronomic characteristics and disease response to domestic and three alien isolates for nine selected varieties and inbreedings, it was indicated some possibility that domestic isolate is a new race of F. oxysporum f. sp. niveum. Six F₁’s from the cross combination of selected resistant one showed no diseased plant and high resistant to F. oxysporum f. sp niveum. Five cross combinations among them could be useful for breeding of resistant cultivars. By the result of disease reaction of the cross combinations between six selected cultivars and inbred lines, progenies from the combination of Pony 19-5 or Crimson Sweet showed high resistance to the disease. It was concluded that these two lines may be useful for the source of resistance to F. oxysproum f. sp. niveum. The disease rate and resistance to the disease were largely depend on both genotypes of watermelon and pathogen and the interaction between them.