ARS | Publication request: USING RAPD MARKERS TO RELATE AN UNDOCUMENTED MYSTERY SOLANUM SUCRENSE POPULATION TO OTHER GERMPLASM IN THE US POTATO GENEBANK

Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 12, 1999
Publication Date: N/A

Interpretive Summary: The goal of potato genebanks is to efficiently acquire, preserve, characterize and distribute genetic material that will be useful to breeders. To serve the broadest possible range of breeding needs, genebanks need to offer the broadest possible range of genetic diversity. But some items which entered genebanks long ago have poor documentation which makes it difficult to judge their genetic relationship to other items. Some might even be duplicates, needlessly taking up limited resources for their maintenance. A case study was done using an undocumented "mystery" population of S. sucrense in the US Potato Genebank to determine if DNA analysis could effectively reveal its genetic relationship to other populations. Random Amplified Polymorphic DNA (RAPD) tests showed that the mystery population was not a duplicate of any other S. sucrense in the genebank, so it should be maintained as a potentially unique source of valuable genes for breeding. Incidentally, no case of duplication existed among any of the 30 other populations tested. Thus RAPD analysis was found to be an easy and precise way to reveal genetic relationships among potato populations and could be a powerful tool for assessing and efficiently managing genetic diversity in potato genebanks.

Technical Abstract: Genetic characterization of germplasm is important for setting objective guidelines for conservation. One regular problem found in genebanks is determining the value of populations with insufficient or unreliable data regarding their geographic origin. In this study, a genetic analysis based on RAPD markers was conducted to characterize a "mystery" population of Solanum sucrense, a polysomic tetraploid potato (2n=4x=48), for which adequate documentation was lacking. The comparative analysis of genetic similarities between this mystery population and each one of 30 other S. sucrense populations in the genebank revealed that it is unique and therefore worthy of conservation. RAPD markers also distinguished 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 differentiate populations within highly heterogeneous tetraploids like S. sucrense, they should be generally useful for determining germplasm organization within potato species.