Linkage and QTL mapping for tuber shape and specific gravity in a tetraploid mapping population of potato representing the russet market class

Authors: PARK, JAEBUM - Oak Ridge Institute For Science And Education (ORISE); Massa, Alicia; DOUCHES, DAVID - Michigan State University; COOMBS, JOSEPH - Michigan State University; AKDEMIR, DENIZ - University College Dublin; YENCHO, G - North Carolina State University; Whitworth, Jonathan; Novy, Richard - Rich

Submitted to: BMC Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2021
Publication Date: 11/3/2021
Citation: Park, J., Massa, A.N., Douches, D., Coombs, J., Akdemir, D., Yencho, G.C., Whitworth, J.L., Novy, R.G. 2021. Linkage and QTL mapping for tuber shape and specific gravity in a tetraploid mapping population of potato representing the russet market class. Biomed Central (BMC) Plant Biology. 21. Article 507. https://doi.org/10.1186/s12870-021-03265-2.
DOI: https://doi.org/10.1186/s12870-021-03265-2

Interpretive Summary: Tuber shape and starch content are important traits for the potato processing industry. Identification of regions of potato chromosomes that impact these traits would benefit potato breeders in developing improved potato varieties. Data on tuber shape and starch content was collected over a 2 year period in Idaho and North Carolina and in one year in Minnesota on a russet potato population consisting of 205 individuals and their parents. Collected data was then used in conjunction with molecular marker data on each individual comprising the population to identify chromosome regions associated with these two traits. Regions on chromosomes 4,7, and 10 were identified as contributing to tuber shape and regions on chromsomes 1 and 5 were associated with contributing to starch content. These finding will be used in developing molecular markers to aid in the selection of individuals having desirable shape and starch content to facilitate the development of new potato varieties.

Technical Abstract: Background: Tuber shape and specific gravity (dry matter) are important agronomic traits in potato processing 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 to facilitate breeding efforts in the russet market class. Two parents, Rio Grande Russet (female) and Premier Russet (male) and their 205 F1 progenies 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. Progenies and parents were previously genotyped using the Illumina SolCAP Infinium 8303 Potato SNP array, with ClusterCall and MAPpoly (R-packages) subsequently used for autotetraploid SNP calling and linkage mapping in this study. The 12 complete linkage groups and phenotypic data were then imported into QTLpoly, an R-package designed for polyploid QTL analyses. Results: Significant QTL for tuber shape were detected on chromosomes 4, 7, and 10, with heritability estimates ranging from 0.09 to 0.36. Significant tuber shape QTL on chromosomes 4 and 7 were specific to Idaho and North Carolina environments, respectively, whereas the QTL on chromosome 10 was significant regardless of growing environment. Single marker analyses identified alleles in the parents associated with QTL on chromosomes 4, 7, and 10 that contributed to significant differences in tuber shape among progenies. Significant QTL were also identified for specific gravity on chromosomes 1 and 5 with heritability ranging from 0.12 to 0.21 and were reflected across environments. Conclusion: Fully automated linkage mapping and QTL analysis were conducted to identify significant QTL for tuber shape and dry matter in a tetraploid mapping population representing the russet market class. The findings are important for the development of molecular markers useful to potato breeders for marker-assisted selection for the long tuber shape and acceptable dry matter required by the potato industry within this important market class.