Resistance of potato varieties to X, Y viruses using molecular markers

The aim of research is to identify and study potato varieties with resistance to the main potato viruses (PVY; PVX) for further use of the varieties in the potato breeding and seed production program. During the molecular screening of potato breeding genotypes, DNA markers were used: the SCAR marker RYSC3 was used to identify the Rуadg gene. The presence of the Rysto gene was determined using the STS marker YES3-3. The Rychc gene was detected using the STS marker RY186 of resistance to the PVX virus - the STS marker PVX of the Rx1 gene. PCR primers and reaction conditions were selected from literature sources. An instrumental line was used to perform PCR analysis. PCR amplifications were performed in a total volume of 25 μl containing 10X Taq DNA polymerase buffer (Synthol), 2.5 mM dNTP mix (Helikon), 2.5 mM aqueous magnesium chloride solution (Fermentas), 5-10 pmol of each primer (Synthol), 0.2 U Taq DNA polymerase (Synthol), 20 ng DNA sample and 13-15 μl autoclaved bidistilled water. All PCR products were separated by electrophoresis on 1.5 % agarose gel in 1× TAE buffer and visualized with ultraviolet (UV). DNA GeneRuler, Thermo FS was used as molecular weight markers. The breeding material was preliminarily assessed in laboratory and field conditions in accordance with the recommendations for the breeding process for potatoes. Total DNA was isolated from the leaves of field potato plants collected during the growing season using the CTAB method. DNA isolated from the leaves of field potato plants was used for analysis using a protocol based on the CTAB method. As a result of the analysis of the potato resistance gene, varieties with R-genes of potato virus resistance were isolated: with the Rysto gene linked to the YES3-3A marker with an expected fragment size of 341 bp (noted in 4 potato samples Darenka, Farn, Rocco). The Rx1 gene, which controls resistance to the virus (PVX), was detected in 2 potato samples.