Introgression of Wild Species Germplasm with Extreme Resistance to Cold Sweetening into the Cultivated Potato

Abstract

Potato (Solanum tuberosum L.) breeders are interested in developing chipping cultivars that can be stored at cold temperatures to reduce storage losses and increase profitability for potato producers. Commercial cultivars accumulate reducing sugars during cold storage, resulting in unacceptably dark chips when processed. In this study, we have identified diploid wild Solanum species accessions that are resistant to cold‐induced sweetening at very low storage temperatures (2°C). Selected accessions were crossed as males to haploids (2n = 2x) of S. tuberosum to produce adapted hybrids, some of which produce acceptable chips following 3 mo of storage at 2°C. Reconditioning for 6 d at 20 to 22°C increased the number of clones with acceptable chip scores by threefold. The best wild species parents were S. raphanifolium 296126, 310998, and 210048. While parental chip scores help to predict offspring performance, progeny testing is important to identify the best cross combinations. The best hybrids have been introgressed into diploid and tetraploid breeding clones. These hybrids produce good tuber type and low levels of reducing sugars under extremely low storage temperatures.

Suppression of the Vacuolar Invertase Gene Prevents Cold-Induced Sweetening in Potato

“…One way to improve existing traits or incorporate novel traits is to introduce germplasm from wild Solanum species into cultivated potato (Plaisted and Hoopes, 1989). Tubers of some wild potato relatives, including lines of S. raphanifolium, S. chacoense, and Solanum okadae, have been shown to produce light-colored fried chips after low-temperature storage (Hamernik et al, 2009;McCann et al, 2010). The differences between members of these species and cultivated S. tuberosum that resulted in light-colored chips were not known.…”

“…Potato chips processed from tubers of S. raphanifolium accessions stored for 3 months at 2°C showed acceptable color (Hamernik, 1998). This extreme cold-chipping phenotype was heritable when cold-chipping S. raphanifolium accessions were crossed with diploid potato clones (Hamernik, 1998;Hamernik et al, 2009).…”

“…Although slow progress has been made over the past several decades toward developing cultivars that maintain relatively low amounts of reducing sugars during cold storage (Love et al, 1998;Hamernik et al, 2009), none of the cultivars in production can be stored at cold temperatures without undergoing CIS. In contrast to S. tuberosum, several wild Solanum species, including some accessions of Solanum raphanifolium (2n = 2x = 24), show excellent potential as cold chippers (Hamernik, 1998;McCann et al, 2010). Potato chips processed from tubers of S. raphanifolium accessions stored for 3 months at 2°C showed acceptable color (Hamernik, 1998).…”

“…In contrast to S. tuberosum, several wild Solanum species, including some accessions of Solanum raphanifolium (2n = 2x = 24), show excellent potential as cold chippers (Hamernik, 1998;McCann et al, 2010). Potato chips processed from tubers of S. raphanifolium accessions stored for 3 months at 2°C showed acceptable color (Hamernik, 1998). This extreme cold-chipping phenotype was heritable when cold-chipping S. raphanifolium accessions were crossed with diploid potato clones (Hamernik, 1998;Hamernik et al, 2009).…”

Pairing analysis and in situ Hybridisation reveal autopolyploid-like behaviour in Solanum commersonii × S. tuberosum (potato) interspecific hybrids

“…The collection provides essential genetic traits for many of the biotic and abiotic threats to the crop (Jansky 2000;Solomon-Blackburn and Barker 2001;Jansky and Peloquin 2006;Hamernik et al 2009), which can be transferred to selected cultivars by introgressive hybridisation. The rich gene pool also contributes to allelic diversity for breeding programmes, and so determines the prospect for selecting desired allele combinations and maximizing heterozygosity, required for yield improvements (Mendoza and Haynes 1974).…”