Discrimination among 136 Tetraploid Potato Varieties by Fingerprints Using Highly Polymorphic DNA Markers

Abstract

The identification of a variety has an important role in the protection of plant breeders' rights and for monitoring seed production and marketing. The objective of our study was to examine whether or not a large number of registered cultivars of European potato ( Solarium tuberosum subsp, tuberosum) could be distinguished using RFLPs (restriction fragment length polymorphisms) as genetic fingerprints. Genomic Southern blots with TaqI‐restricted DNA of 136 tetraploid potato varieties were hybridized to highly polymorphic potato RFLP markers. The use of four markers was sufficient to identify 130 of 136 varieties. Three pairs of varieties were identical with all markers evaluated. One marker, GP35, was the most effective: out of 134 varieties analyzed with this probe, 122 had unique RFLP patterns. The remaining 12 varieties were divided into six pairs, each showing an identical pattern. Sequence analysis showed that GP35 was not homologous to minisatellite sequences. The probability of finding a random match of RFLP patterns between two tetraploid varieties with marker GP35 was estimated to be 0.63 × 10 −4 . Variety identification by RFLP fingerprints is therefore feasible in potato.