Laboratory determination of brown rot potato defeating of different varieties

Goal. To determine resistance or susceptibility to brown rot potato in controlled laboratory terms with the perspective for usage receiving data in practice for new varieties breeding by breeding institutions. Methods. The following laboratory methods were used for planting material defeating by brown rot potato causative agent suspense — potato pieces in tubes and potato plant aboveground part grow on artificial substrate. These methods allowed to perform the standard terms during the repeated experiments. Results. The tissue darkening was observed in tuber’s vascular part by the defeating results. It run from the pathogen penetrating place. The defeating degree of development reached 3—4 points. The following varieties: Volodarka, Zvizdal, Opillya, Povin, Rodynna, Schedryk in 2019 and Misteria Soncedar in 2020 were the most defeated by disease causative agent. The defeated plant’s aboveground part withered, changed colour on brown or bronze, curled and slowly dead, the potato’s stem through vascular bundle became brown. This process run slowly from inoculation place. The plant’s slow wither caused by water transport breach on pathogen — defeated vascular. This process expressed on varieties Vendrusha and Soncedar. The less defeated aboveground part were on Glazurna, Knyazha, Poliske dzerelo. Prolisok in 2019, Slauta and Strumok in 2020. Conclusions. The tuber’s and aboveground potato part defeating level of national breeding was determined during the artificial inoculation by brown rot potato causative agent. There were no determined samples with enough resistance to disease. The technique of growing and saving of researched plants in controlled laboratory conditions (with artificial substance usage) adapted for practical usage.