MARKER-ASSISTED SELECTION FOR VIRUS RESISTANCE IN POTATO: OPTIONS AND CHALLENGES

Abstract

Viruses are one of the major problems in potato cultivation. Resistance breeding is the only effective method to control viruses in a potato crop. The conventional breeding methods, however, are slow and cumbersome due to tetraploid and heterozygous status of cultivated potatoes. A number of genes for resistance to viruses, such as PLRV, PVY, PVX, PVS, PVM and PVA derived from wild/cultivated Solanum species have been identified and mapped using molecular markers. The genes/QTLs conferring extreme resistance or hypersensitivity response to viruses, for which markers are available, have been successfully introgressed into potato. Some of the easy assay markers for virus resistance genes Ry_adg, Ry_sto (=Ry-f_sto), Rychc, Ny-1, Rx, Nb, Ns, Rm, Gm, Plrv.1 (QTL) and Plrv.4 (QTL) have been developed for marker-assisted selection (MAS) in potato breeding. Agarose-based diagnostic PCR markers like ISSR, CAPS, RAPD, SCAR and STS have the potential for faster and accurate potato breeding for virus resistance through MAS.