Identification of potato pathogens using different diagnostic methods

Abstract. Potato diseases have far reaching implications for the agricultural industry as they not only reduce productivity and quality of potato crop but also negatively affect the livelihood of farmers. The purpose of the studies detection and identification of potato phytopathogens by visual assessment, real time polymerase chain reaction (PCR) and molecular genetic screening for phytopathogen resistance genes. Methods. Visual evaluation of each potato variety for major fungal, viral and bacterial diseases was carried out during the period of full sprouting, at plant height of 15–20 cm and in the phase of full flowering. The percentage of plants affected by diseases in relation to the total number of inspected plants was calculated. Diagnosis of resistance of potato samples to diseases was carried out on the basis of PCR. DNA markers of phytopathogen resistance genes YES3-3A, RYSC3, Ry186, TG 689, Gro1-4-1, Gpa2-2, PVX were used for molecular screening of potato. Infection of samples by PCR-RV (real-time) was determined using reagent kits of Syntol LLC Potato Virus X and Potato Virus Y, Potato spindle tuber viroid-PB, Clavibacter michiganensis subsp. sepedonicus-PB, Dickeya spp-PB. Results. According to the results of visual evaluation, the absence of symptoms of wrinkle mosaic in 20% of hybrids, mottle mosaic in 40%, mosaic leaf curl in 96 %, leaf curl in 72 hybrids, black leg in 100%, phytophthorosis in 88% of hybrids, alternaria in 84 %, rhizoctoniosis in 96 % of hybrids were observed. According to the results of PCR-RV analysis in 21 samples detected virus Y. The scientific novelty consists in the diagnosis of potato viruses using traditional visual assessment with the use of molecular markers that allow to identify correlation relationship between trhis methods.