Quantitative Trait Loci for Resistance to Common Scab and Cold‐Induced Sweetening in Diploid Potato

Abstract

The development of germplasm with resistance to common scab and cold-induced sweetening is a high priority for the potato (Solanum tuberosum L.) industry. A mapping population was developed from mating two individuals of a diploid family generated by crossing the susceptible cultivated potato clone US-W4 to the highly resistant wild relative (Solanum chacoense Bitter) clone '524-8'. Progeny were evaluated in replicated field trials. Tubers were scored for percentage of surface area with scab lesions, scab lesion type, cold-induced sweetening, average tuber weight, and dry matter. Plants were evaluated for vine maturity. A genetic map was constructed, quantitative trait loci (QTLs) were identified, and the gene action of significant QTLs was characterized using 1606 single nucleotide polymorphisms (SNPs). Significant QTLs for common scab percentage of surface area covered with lesions and lesion type were identified in overlapping regions on chromosome 11 (R 2 = 21.0 and 18.2%, respectively). Quantitative trait loci were identified on chromosomes 4 (R 2 = 17.1%) and 6 (R 2 = 19.4%) for cold-induced sweetening, chromosome 5 for maturity (R 2 = 29.8%), and chromosome 1 (R 2 = 26.3 and 22.0%) for average tuber weight. Identification of QTLs is the first step toward developing molecular markers for breeders to efficiently integrate these desirable traits into cultivars.

Linkage analysis and QTL mapping in a tetraploid russet mapping population of potato

“…A recent study on cold-induced sweetening in diploid potato, Braun et al [ 22 ] reported two QTLs associated with resistance to the accumulation of reducing sugars, one on chromosome 4 and another on chromosome 6. The flanking SNP markers of these QTLs (Table 3 in Braun et al [ 22 ]) encompass the SNPs solcap_c2_12976 and solcap_snp_c2_56145 reported here for chromosomes 4 and 6, respectively.…”

“…A recent study on cold-induced sweetening in diploid potato, Braun et al [ 22 ] reported two QTLs associated with resistance to the accumulation of reducing sugars, one on chromosome 4 and another on chromosome 6. The flanking SNP markers of these QTLs (Table 3 in Braun et al [ 22 ]) encompass the SNPs solcap_c2_12976 and solcap_snp_c2_56145 reported here for chromosomes 4 and 6, respectively. Considering the high degree of concordance between linkage maps based on the Infinium 8303 Potato Array and the reference potato genome sequence [ 2 , 31 ], it is reasonable to assume that these are homologous QTL regions.…”

“…Considering the high degree of concordance between linkage maps based on the Infinium 8303 Potato Array and the reference potato genome sequence [ 2 , 31 ], it is reasonable to assume that these are homologous QTL regions. Yet, the SNP alleles underlying positive effects in Braun et al [ 22 ] need to be determined.…”

“…Soltis-Kalina et al [ 21 ] identified two major QTLs for chip color on chromosomes 1 and 6 in a diploid mapping population. More recently, Braun et al [ 22 ] reported two QTLs for resistance to cold-induced sweetening on chromosomes 4 and 6 of diploid potato. Most of these studies have been performed on diploid potato germplasm.…”

Quantitative trait loci for starch-corrected chip color after harvest, cold storage and after reconditioning mapped in diploid potato

“…Mapping of quantitative trait loci (QTLs) has been performed in a number of experimental populations of diploid potatoes (Douches and Freyre 1994;Menendez et al 2002, Werij et al 2012Sołtys-Kalina et al 2015;Śliwka et al 2016;Braun et al 2017;Xiao et al 2018) in addition to a few association studies (Li et al 2008(Li et al , 2010Schreiber et al 2014). The genes involved in starch synthesis and degradation, the Calvin cycle and photorespiration, the glycolysis, oxidative pentose phosphate pathway, and the Krebs cycle are distributed across all twelve potato chromosomes (Chen et al 2001).…”