A core subset of the ex situ collection of S. demissum at the US Potato Genebank

Authors: DEL RIO, ALFONSO - University Of Wisconsin; Bamberg, John

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/2020
Publication Date: 9/1/2020
Citation: Del Rio, A.H., Bamberg, J.B. 2020. A core subset of the ex situ collection of S. demissum at the US Potato Genebank. American Journal of Potato Research. 97:505–512. https://doi.org/10.1007/s12230-020-09799-9.
DOI: https://doi.org/10.1007/s12230-020-09799-9

Interpretive Summary: Potato is the nation's top vegetable, so improving it has value to US agriculture and consumers. An important way to improve the crop is through breeding using exotic relatives of the cultivated potato. For this purpose, the nation maintains gene-banks of many samples. It is difficult and expensive in time and money to screen all these stocks for useful traits. It helps to identify a smaller subset "core" group of samples that represent most of the traits within the whole species. We did this for the wild potato species Solanum demissum, identifying 38 samples that capture 96% of the genetic markers in the entire set of the 149 samples available at the gene-bank. Now we are able to offer breeders and researchers the obvious efficiency of a pond that is much smaller than the whole lake, but has almost as many fish.

Technical Abstract: Useful genetic diversity found in wild potato germplasm is important for progress in potato breeding and science. An effective way to maximize its utilization is through characterization of ex situ collections. For example, marker-based core subsets from large collections are an effective strategy to accelerate evaluation, utilize germplasm and, enhance cost-effectiveness. This project used AFLP markers to create a core subset for the US Potato Genebank’s collection of S. demissum. This species from Mexico and Guatemala is known for excellent levels of late blight resistance and frost tolerance. A total of 149 accessions with diverse geographic origin were characterized with 1403 AFLP markers; these markers were effective on determining genetic associations among the accessions. For the core subset, the AFLP loci were considered as traits, with the presence of the marker as the required state to include in a core. The results of the analyses identified that 10 of the accessions of demissum captured 83% of all the markers detected in the whole collection. The inclusion of 28 additional accessions, which had between 1 to 5 unique markers, resulted in a core set of 38 accessions that captured 96% of all the marker diversity. We expect this can benefit the genebank and the potato community by opening opportunities for research, trait screenings and, marker association studies