|Jaebum Park||USDA-ARS, Aberdeen, ID|
|Deniz Akdemir||University College Dublin|
|Jonathan L. Whitworth||USDA-ARS|
|Richard G. Novy||USDA-ARS|
Potato tuber shape and specific gravity are important agronomic traits in processed food industries and impact production costs, quality, and consistency of the final processed food products such as French fries and potato chips. In this study, linkage and QTL mapping were performed for these two traits to allow for the implementation of marker-assisted selection. Two parents, Rio Grande Russet (female) and Premier Russet (male) and their 205 F1 progeny were initially phenotyped for tuber shape and specific gravity in field trials conducted in Idaho and North Carolina in 2010 and 2011, with specific gravity also being measured in Minnesota in 2011. Progeny and parents were genotyped using the SolCAP 8303 SNP chip, with ClusterCall and MAPpoly (R-packages) subsequently used for autotetraploid SNP calling and linkage mapping. The 12 complete linkage maps and phenotypic data were then imported into QTLpoly, an R-package designed for polyploid QTL analyses. Significant QTL peaks for the tuber shape were detected on chromosomes 2, 4, and 10, with QTL heritabilities (h2QTL) ranging from 0.09 to 0.28. Significant QTL peaks for specific gravity were also identified on chromosome 1, 2, 5, 7, 11, and 12, with h2QTL ranging from 0.12 to 0.26. Unlike the previous software developed for autotetraploid QTL analysis, the MAPpoly and QTLpoly helped us to conduct fully automated linkage mapping and QTL analysis.