Endonuclease restriction of SCAR amplicons SC811 is required to identify Ns-false-positive markers in PVS-susceptible potato cultivars.

The Ns gene confers resistance of potato to Potato virus S (PVS). Sixteen German and Dutch potato cultivars, all registered in Poland, were found to be susceptible to PVS infection. However, scoring of the cultivars for the presence of the Ns-linked SCAR marker SC811(454) revealed additional amplicons with a similar electrophoretic migration rate as that of SC811(454), which resulted in ambiguous determination of the genotype at the Ns locus. MboI or FokI treatment of the PCR products allowed to detect their Ns-unspecificity in PVS-susceptible potato cultivars.