Efficiency of selecting strawberry genotypes resistant to fungal root and crown diseases while infecting germinating seeds

The most harmful strawberry pathogens are fungal diseases of root and crown, which are caused by Verticillium dahliae Kleban, V. albo-atrum Reinke & Berthold, Fusarium oxysporum Schltdl., Colletotrichum acutatum J.H. Simmonds. The main goal of our research was to determine the effectiveness of different ways of treatment for artificial infection of strawberry seed material. This will simplify the work in comparison to the traditional infection of seedlings by dipping roots into a pathogen spore suspension when transplanting. The most effective way of inoculating strawberries with the Verticillium is to infect seeds which germinated in a humid box by spraying them with a spore suspension. This method of inoculation with two pathogens (V. dahlia, V. albo-atrum) together killed 96.3-100% of the seedlings from the non-resistant maternal component and not more than 25.0-57.9% of those obtained from the resistant maternal form. In case of inoculation with Fusarium oxysporum (Fusarium wilt), the best options were spraying the seeds with the spore suspension and infecting the germinated seeds in a humid box with inoculum (the latter method is labor consuming). The symptoms of the disease were evident in 100% of seedlings from the non-resistant maternal component; 55.6 and 57.1% of seedlings from the resistant maternal form. The most effective methods of Colletotrichum acutatum (anthracnose crown rot) infection are sowing seeds in infected soil and infecting seeds by spraying with a pathogen spore suspension. The infection efficiency was up to 100% for seedlings from non-resistant maternal component; 62.5 and 25.0% of seedlings from the resistant maternal form. The investigated methods should be used to improve strawberry selection for disease resistance.