Genetic similarity of four strawberry cultivars in respect to Verticillium wilt susceptibility under in vitro selection

Abstract

Verticillium wilt caused by pathogenic soil fungus – Vertcillium dahliae Kleb. is one of the most serious strawberry diseases not treated chemically. The strawberry is a species more or less susceptible to Verticillium sp., hence the need to select new genetically resistant cultivars. In this study, susceptibility of four strawberry cultivars to Verticillium wilt was examined under in vitro selection conditions as regards the genetic similarity of selected resistant plants. Microplants of 4 strawberry subclones obtained by in vitro cloning of each cultivar were inoculated in vitro with liquid mycelial homogenate of the pathogen. Development of disease symptoms was observed after 15, 30, 45, 60 and 75 days post inoculation. Results revealed differences of susceptibility to V. dahliae which depended on the subclone. The least susceptible to Verticillium wilt turned out to be ‘Plena’ subclone, followed by the ‘Elsanta’, ‘Feltar’ and ‘Teresa’ subclones. The highest genetic similarity of 59% was found between ‘Elsanta’ and ‘Teresa’ subclones, which after 75 days from inoculation were also characterized by a very similar percentage of resistant plants.