Use of a single probe CP58 for simultaneous selection of resistance genes to potato virus Y (PVY), PVA and cyst nematode (GCN) in the tuber - bearing Solanum Hamalainen 1 , J . H . , Valkonen 1 , J . P . T . , Pineda 2 , O . , Slack 2 , S . , Gebhardt 3 , C . , and Watanabe 4 , K . N . 1 . Swedish Univ . Agr . Sci . , Uppsala, Sweden; 2 . Mendel Biotechnology, 21375 Cabot Blvd . ,Hayward, CA, 94546, USA;   3 . Max - Planck Inst . - Koln, Germany; 4 . Fac . Biosci . , Kinki Univ . , Japan Potato virus Y(PVY) is the major viral pathogen of potato in most temperate areas in the world, e . g .   Northern Europe, North Eastern region of USA and Canada, and Hokkaido, Japan . Potential yield loss could be 70% or even higher . PVA is also a causal agent for the viral disease commonly occurring in temperate zones . Cultivars with resistance to PVY and PVA have promise as a persistent and cost - effective means of control augmented by a strict seed certification system .    Potato golden cyst nematode   (GCN, Globodera rostochiensis ), pathotype Ro1 occurs in the same regions as PVY, and also causes serious damage to potato production . Extreme resistances (ER) are available against both PVY and GCN, and hypersensitive resistance is available against PVA . The ERs to PVY are available from several cultivated and wild relative species: S . tubersum ssp . andigena ( Ryadg ), S . stoloniferum ( Rysto ), S . chacoense ( Rychc ) and putative resistance loci were reported on S . brevidens and S . phureja . Ryadg and Rysto are single dominant genes . The ER genes to GCN are also available from a couple of sources: the major source is H1 gene from S . tubersum ssp . andigena . The HR gene against PVA is also located on Chrom XI of potato (Hamalainen et al . 2000) with the same region as Ryadg . To facilitate potato breeding for the resistances, molecular markers have been employed on these traits . Ryadg is located on Chromosome XI at the proximal end, closely linked with RFLP markers such as TG508, GP125, CD17, and CT168 . CP58(A) on Chrom XI was successful in distinguishing Ryadg (R) and S genotypes in 96% out of 200 cultivars and breeding lines from the Americas and