Solanum acaule (acl) and Solanum commersonii (cmm) represent the extremes of frost tolerance and cold acclimation ability among potato species. We have combined these species with cultivated S. tuberosum (tbr) to develop a potato with desired tuber traits and a high degree of frost tolerance. For this purpose diploid cmm was made 4x and crossed with naturally 4x acl. The F1 and F2 appear to exhibit hybrid vigor for vine growth for flowering, but none had frost tolerance greater than the parents. The F1 and F2 were crossed with S. tuberosum ssp. andigena and Katahdin via 2n eggs resulting in 6x 3-way hybrids. These hybrids were evaluated both in the field and laboratory for frost tolerance and acclimation ability. Results showed an increase of 1°C of frost tolerance and 2°C increase in cold acclimation capacity in the hybrids as compared to the sensitive tbr parents. Some of the 6x (3-way) hybrids produced significant tubers but yield and earliness needs much improvement. These results demonstrate that it should be possible to move both non acclimated freezing tolerance and cold acclimation ability from wild to cultivated species and offer exciting opportunities to enhance potato production in frost prone areas in the world.
Supported by USDA/NRI grant 91-3700-6636 to J.P.P. and J.B.B..