Core collections of potato (Solanum) species native to the USA

Authors: Bamberg, John; DEL RIO, A - University Of Wisconsin; KINDER, D - Ohio Northern University; LOUDERBACK, L - University Of Utah; PAVLIK, B - University Of Utah; FERNANDEZ, C - University Of Wisconsin

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2016
Publication Date: 10/17/2016
Publication URL: http://handle.nal.usda.gov/10113/5642506
Citation: Bamberg, J., del Rio, A., Kinder, D., Louderback, L., Pavlik, B., Fernandez, C. 2016. Core collections of potato (Solanum) species native to the USA. American Journal of Potato Research. 93(6):564-571. doi: 10.1007/s12230-016-9536-2.

Interpretive Summary: Potato (Solanum tuberosum) is the most important vegetable crop in the US and world, and has a rich resource of about 100 wild relative species that can be used for breeding and research to improve the crop. Our national genebank responsible for keeping this resource is the US Potato Genebank, near Sturgeon Bay, Wisconsin. While most wild potato species originate in Latin America, two species are native to the USA, and the genebank has collected hundreds of samples of them over the past 50 years. We would like to know which samples have the most genetic richness. Those would obviously have priority for preservation at the genebank and be the most promising for evaluation for useful breeding traits. The origin sites for samples with the most genetic richness would also be most promising for additional sampling, and those sites would deserve the most emphasis for habitat protection. We produced genetic markers for all USA samples, and thus were able to rank samples for genetic richness. This information can now be used by genebank staff and germplasm users. We now also have an opportunity to ask "why?"-- how might climate, habitat, location, and human, and other influences be linked with the sites with the most genetic richness?

Technical Abstract: Potato has two wild relatives native to the USA, Solanum jamesii (jam) and S. fendleri (fen). Core collections are a useful tool for genebanks, identifying a ranked minimum number of samples that together encompass most of the total diversity. With diversity measured as presence of AFLP bands, core collections were made for each species such that > 90% of diversity was captured in a minimum of populations. For fen, bulks containing about 25% of populations accomplished that standard. For jam, a single "mega-population" at Mesa Verde, CO, consisting of several thousand ramets was found to encompass 82% of the AFLP bands detected in all samples across the entire USA range. Core members for both jam and fen originated mostly from the northern part of the range. That suggests that these areas merit more collecting. If resources for germplasm preservation and evaluation are limited, samples in the core collections should take top priority.