In vitro technology at the US Potato Genebank

The US Potato Genebank in Sturgeon Bay, Wisconsin, is the national germplasm collection for the world's most important vegetable crop. It contains about 6,000 accessions of 100 species of tuber-bearing relatives of Solanum tuberosum. The potato of commerce is a clonal crop susceptible to many systemic pathogens, so the genebank routinely uses in vitro clonal maintenance and distribution for named cultivars. In vitro management is also the tool of choice for various breeding and genetic stocks of interest to breeders and researchers. Long-term backup cryopreservation of clones is done at the base collection in Fort Collins, Colorado. In vitro techniques also play an important role in virus elimination from clones. Recently, in vitro propagation has expanded to the temporary safekeeping of meristem propagules in antimicrobial medium during plant collecting expeditions in the southwest USA. The genebank's mission includes promoting technology that supports expanded use of the germplasm, in particular, finding ways to overcome interspecific hybridization barriers. Thus, in vitro techniques such as pollen viability testing, ploidy manipulation, protoplast fusion, and embryo rescue have contributed technology for major advances in interspecific hybridization, utilization of noncommercial species, and introgression of genes from wild near-relatives. Finally, advancing in vitro technology holds promise as a tool for mass bioassay and selection of seeds, pollen, or somaclones for useful traits.