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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #318129
Title: QTL mapping of potato chip color and tuber traits within an autotetraploid family

Author
item RAK, KYLE - University Of Wisconsin
item Bethke, Paul
item PALTA, JIWAN - University Of Wisconsin

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2017
Publication Date: 1/24/2017
Publication URL: http://handle.nal.usda.gov/10113/5742468
Citation: Rak, K., Bethke, P.C., Palta, J.P. 2017. QTL mapping of potato chip color and tuber traits within an autotetraploid family. Molecular Breeding. 37(2):15. doi: 10.1007/s11032-017-0619-7.

Interpretive Summary: The methods used to produce new varieties of potato have changed little over the past century. New tools for plant breeding are becoming available, and many of these relate variation in DNA sequences between individuals with differences in desirable traits. We identified 41 regions within the DNA of cultivated potato that contributed to commercially important traits including total yield, potato shape, and potato chip color. Each of these regions has an associated DNA marker that can be used as an identifier for tracking regions contributing favorably to potato tuber quality as part of a molecular breeding program. A combination of conventional and molecular breeding for the selection of parents and evaluation of offspring is likely to increase the efficiency of potato breeding efforts. This will make it possible to bring new potato varieties to market more rapidly and will allow the potato industry to respond more quickly to consumer demands and changes in production practices that impact profitability.

Technical Abstract: Cultivated potato (Solanum tuberosum L.) is a highly heterozygous autotetraploid crop species, and this presents challenges for traditional line development and molecular breeding. Recent availability of a single nucleotide polymorphism (SNP) array with 8303 features and software packages for linkage and association mapping in autotetraploid species, present new opportunities for the identification of genomic regions that contribute to high-value traits in cultivated potato. A biparental tetraploid potato population was evaluated across three field seasons and storage trials in order to identify quantitative trait loci (QTL) for multiple tuber traits including fried chip color after 5.5-7.2°C storage. Tetra-allelic dosage information was used to construct a genetic linkage map that covered 1041 cM and contained 2095 SNP markers with a median marker interval of 0.4 cM. A total of 41 QTL were identified for flower color, tuber yield, tuber number per plant, tuber weight, tuber size, and chip color after various storage regimes. Moderate effect QTL for chip color at 3 months were identified that co-localized with candidate genes vacuolar invertase (VInv), invertase inhibitor (INH2), and apoplastic invertase (Invap-b). A separate QTL for chip color after 6 months of storage was identified in the short arm of chromosome 2, and this locus may contribute to variation in senescent sweetening resistance. QTL for tuber weight, length, and width co-localized with a known QTL for plant maturity on chromosome 5. Genome-wide association mapping (GWAS) using a polyploid model detected the tuber size QTL and identified a number of candidate SNPs, but was unable to detect markers significantly associated with chip color.