Identification of host gene conferring resistance to Potato virus Y using Ry gene-based molecular markers

Abstract

Potato (Solanum tuberosum L.) is the third most important food crop of the world and vegetatively propagated mainly through tubers. Tuber yield mainly depends on the quality of potato ‘seed tubers’ especially free from viral diseases, otherwise it proliferates over the successive clonal generations. More than 30 different viruses infect potato, and potato virus Y (PVY) is the most important one in the north-western/ north-eastern parts and plateau regions of India. So, in this study breeding for virus resistance, seventy-one exotic potato germplasm were evaluated for the host-resistance gene using molecular makers linked to the Ry genes. Germplasm were also examined for the extreme resistance to PVY by Ry gene-linked markers and confirmatory results of resistance by ELISA testing. Among all, 26 germplasm (group I) showed the presence of Ryadg gene as revealed by SCAR (RYSC3) and CAPS (ADG2/BbvI) markers and also exhibited resistance to PVY by ELISA testing after mechanical inoculation of PVYO isolate. This group I germplasm appear to be future research materials for the introgression of resistant gene Ryadg derived from S. tuberosum spp. andigena using marker-assisted selection (MAS) in the Indian potato breeding. In addition, 45 germplasm (group II) did not amplify any of the markers of Ry genes available to date derived from wild Solanum species and their resistance/susceptibility is also not known. Thus, these research findings highlighted the use of the Ryadg gene-based molecular markers to accelerate the potato breeding through MAS.