RAPD markers efficiently distinguish heterogenous populations of wild potato (Solanum)

Genetic characterization of germplasm is important for setting objective gu idelines for conservation. One common problem found in genebanks is determi ning the value of populations with insufficient or unreliable data regardin g their geographic origin. In this study, a genetic analysis based on RAPD markers was conducted to characterize a 'mystery' population of Solanum suc rense, a polysomic tetraploid potato (2n=4x=48), for which adequate documen tation was lacking. The comparative analysis of genetic similarities betwee n this mystery population and each one of 30 other S. sucrense populations in the genebank revealed that all populations within this species, includin g the mystery population, are significantly different from being duplicates , and are therefore worthy of separate conservation. RAPD markers also dist inguished the mystery population from closely related tetraploid species S. oplocense, S. gourlayi and S. tuberosum ssp. andigena, suggesting that it is also not a duplicate of a population of these species. If RAPDs can clea rly differentiate populations within highly heterogeneous tetraploids like S. sucrense, they should be generally useful for determining germplasm orga nization within potato species.