Comparison of reputed duplicate populations in the Russian and US potato genebanks using RAPD markers

The Association of Potato Intergenebank Collaborators (APIC) produced a glo bal inventory of wild potato genetic resources that is available on the Int ernet (www.potgenebank.org/ipd). This database shows that, in many cases, s everal genebanks have samples of the progeny from a single original germpla sm collection. The assumption has been that these samples are genetically e quivalent, so all the characterization and evaluation data gathered on a se edlot from one genebank can be applied to all the other "duplicate" seedlot s in other genebanks. This assumption was tested by comparing 25 pairs of r eputed duplicates in the VIR (St. Petersburg, Russia) and US (Sturgeon Bay, USA) potato genebanks using RAPDs. In 23 of 25 populations, reputed duplic ates among genebanks had significantly less similarity than replicate sampl es taken from a single population. The average genetic similarity of repute d duplicates was 93%, and the lowest was 81%. Thus, users of germplasm shou ld be aware that reputed duplicate populations from these genebanks may not be genetically identical.