Screening of potato breedung lines for the potato virus Y resistance genes Rychc and Ryadg

Abstract

Goal. Molecular identification of carriers of the potato virus Y (PVY) resistance genes Rychc and Ryadg among potato lines of the Polissia Research Station of the Institute of Potato Growing of the National Academy of Agrarian Sciences of Ukraine.
 Methods. Seventy potato lines produced by the Polissia Research Station of the Institute of Potato Growing were studied. We used molecular markers indicating the presence of specific Ry genes in the genome of the potato lines. Those genes are responsible for the plant’s response to the pathogen by the extreme resistance (ER) type: the Ryo186 marker for the identification of the Rychc gene, and RYSC-3 for the determination of the Ryadg resistance gene. The gene Ry chc, derives from Solanum chacoense, and the Ryadg gene from S. tuberosum ssp. andigena. For determining the PVY resistance genes, PCR analysis was used, and PCR products were analyzed by electrophoresis in an agarose gel supplemented with ethidium bromide to visualize amplicons.
 Results. Screening of carriers of resistance alleles with the molecular marker Ruo186 showed that 53 lines (75.72%) carried the resistance gene Rychc. The Ryadg resistance allele was identified in 7 lines (10%) using the RYSC-3 marker. Among the analyzed sample, there were three lines (4.2%) which simultaneously carried both PVY resistance genes: P.17.36-8, P.16.21-8, and P.17.21/36. When compared with the studies of other authors, in our sample of potato breeding lines we have mostly a similar percentage of occurrence of the Ryadg gene and a much higher frequency of the Rychc gene.
 Conclusions. Thus, the potato lines of the Polissia Research Station of the Institute of Potato Growing with the identified resistance genes have the potential for extreme resistance to most PVY strains, including the PVYNTN strain.