Location: Vegetable Crops Research Unit
Title: Introgression of Wild Species Germplasm with Resistance to Cold Sweetening into the Cultivated Potato Authors
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 26, 2008
Publication Date: February 1, 2009
Citation: Hamernik, A.J., Hanneman Jr, R.E., Jansky, S.H. 2009. Introgression of Wild Species Germplasm with Resistance to Cold Sweetening into the Cultivated Potato. Crop Science. 49:529-542. Interpretive Summary: Most potatoes are stored before they are processed. Cold storage temperatures minimize storage losses and increase profitability for potato producers. However, potatoes stored in the cold accumulate sugars, resulting in dark chips when processed. We have identified wild relatives of potato that do not accumulate these sugars. Consequently, they produce light colored chips after cold storage. These wild species have been crossed to the cultivated potato. Some of the hybrids produce light chips after storage at very cold temperatures. Additional crosses have been made to produce several breeding lines with good tuber type and the ability to chip following cold storage.
Technical Abstract: Potato breeders are interested in developing chipping cultivars that can be stored at cold temperatures to reduce storage losses and increase profitability for potato producers. Commercial cultivars accumulate reducing sugars during cold storage, resulting in unacceptably dark chips when processed. In this study, we have identified diploid wild Solanum species accessions that are resistant to cold-induced sweetening at very low storage temperatures (2oC). Selected accessions were crossed as males to haploids (2n=2x) of S. tuberosum to produce adapted hybrids, some of which produce acceptable chips following three months of storage at 2oC. Reconditioning for six days at 20oC increased the number of clones with acceptable chip scores by three-fold. The best wild species parents were S. raphanifolium 296126, 310998, and 210048. While parental chip scores help to predict offspring performance, progeny testing is important to identify the best cross combinations. The best hybrids have been introgressed into diploid and tetraploid breeding clones. These hybrids produce good tuber type and low levels of reducing sugars under extremely low storage temperatures.