Selection for cold chipping genotypes from three early generations in a potato breeding program

Chipping potatoes are an important market for the processing industry. Of the traits influencing chip quality, chip color is market limiting since other traits have diminished value without light chip color. Cold (4degreesC) storage can reduce storage losses and cultivars producing light colored chips directly from cold storage are needed for this reason. Selection for cold chipping cultivars is traditionally practiced by visual evaluation of progeny the first few years in the field, followed by selection for cold chipping in years 4-5. Early generation selection for cold chipping may reduce cultivar development time by identifying good chipping progeny, families and parents earlier in the breeding cycle. Progeny from 175 4x x 4x families were evaluated from three early generations. They were greenhouse grown tubers (GGT) evaluated after 6 mo. storage using randomly selected progeny, and field grown single hills propagated from either seedling transplants (FTR), or from greenhouse grown tubers (FGT). Progeny from field grown generations were selected first by visual evaluation, and then by random selection and chipped after 6 mo. ( visual selections) or 3 and 6 mo. storage ( random selections). Cold chipping progenies were found in all three early generations. The earliest generations for selection are GGT or FTR, but may be less efficient than FGT. Correlations suggest that reliable parent and family selection is possible using GGT data. Visual selection eliminated 4/5 of the good chipping progeny, while identifying 8 of 11,714 genotypes combining visual merit and cold chipping potential. Increased genetic variation and sexual polyploidization are possible strategies for increasing the number of desirable genotypes.