Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2008
Publication Date: 9/1/2008
Citation: Haynes, K.G. 2008. Heritability of Chip Color and Specific Gravity in a Long-Day Adapted Solanum phureja-S. stenotomum Population. American Journal of Potato Research. 85:361-366. Interpretive Summary: Potato varieties for processing into chips must produce tubers with high dry matter content and light colored chips when fried. There is very limited genetic variation for high dry matter content in commercial potato varieties. We have bred related potato species for high dry matter content, but until now, it was unknown how well they might chip. This study found that about 1/3 of the individuals in the high dry matter population we have developed produce a satisfactory chip color. This population will provide additional genetic variation for developing new potato varieties for the chipping industry.
Technical Abstract: Acceptable chip color and high specific gravity are important characteristics for chipping potatoes. High specific gravity in U.S. chipping varieties traces back to B5141-6 (‘Lenape’). In an effort to expand the germplasm base for high specific gravity, a long-day adapted diploid hybrid Solanum phureja – S. stenotomum population with high specific gravity was developed. The purposes of this study were to evaluate this population for its chipping potential and estimate heritability for chip color and specific gravity. The population consisted of four clones from each of 72 maternal half-sib families and represents the third cycle of selection for high specific gravity in this population. Clones were grown in a randomized complete block design at Presque Isle, Maine in 2004 and 2005 along with the check variety ‘Atlantic’. Five tubers from each clone per replicate were processed into chips in early December following 10 C storage both years. Individual chips were rated on a 1-10 scale, with < 7 considered an acceptable color. The average chip scores of the diploid clones and Atlantic were 7.3 and 6.8, respectively. The average specific gravities of the diploid clones and Atlantic were 1.099 and 1.091, respectively. Four diploid clones had significantly higher specific gravity and lighter chip color than Atlantic; 93 diploid clones had significantly higher specific gravity and chip color equal to Atlantic. Broad-sense heritabilities and their 95% confidence interval for chip color and specific gravity were 0.68 (0.59-0.74) and 0.78 (0.70-0.81), respectively. Narrow-sense heritabilities for chip color and specific gravity were 0.24 + 0.26 and 0.32 + 0.26, respectively. About one-third of the population possesses both high specific gravity and acceptable chip color and could prove useful in expanding the tetraploid germplasm base for processing traits.