Key messageSNPs in candidate genesPain-1,InvCD141(invertases),SSIV(starch synthase),StCDF1(transcription factor),LapN(leucine aminopeptidase), and cytoplasm type are associated with potato tuber yield, starch content and/or starch yield.AbstractTuber yield (TY), starch content (TSC), and starch yield (TSY) are complex characters of high importance for the potato crop in general and for industrial starch production in particular. DNA markers associated with superior alleles of genes that control the natural variation of TY, TSC, and TSY could increase precision and speed of breeding new cultivars optimized for potato starch production. Diagnostic DNA markers are identified by association mapping in populations of tetraploid potato varieties and advanced breeding clones. A novel association mapping population of 282 genotypes including varieties, breeding clones and Andean landraces was assembled and field evaluated in Northern Spain for TY, TSC, TSY, tuber number (TN) and tuber weight (TW). The landraces had lower mean values of TY, TW, TN, and TSY. The population was genotyped for 183 microsatellite alleles, 221 single nucleotide polymorphisms (SNPs) in fourteen candidate genes and eight known diagnostic markers for TSC and TSY. Association test statistics including kinship and population structure reproduced five known marker–trait associations of candidate genes and discovered new ones, particularly for tuber yield and starch yield. The inclusion of landraces increased the number of detected marker–trait associations. Integration of the present association mapping results with previous QTL linkage mapping studies for TY, TSC, TSY, TW, TN, and tuberization revealed some hot spots of QTL for these traits in the potato genome. The genomic positions of markers linked or associated with QTL for complex tuber traits suggest high multiplicity and genome wide distribution of the underlying genes.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-016-2665-7) contains supplementary material, which is available to authorized users.

We have used 19 SSR markers to fingerprint 41 local potato cultivars from 10 locations of Tenerife Island. These varieties represent relicts of the early introductions originating from South America and have been characterised previously morphologically and ecophysiologically. The SSR primers generated a varying degree of polymorphisms. A total of 67 alleles were observed, 12 of them were present in all cultivars. Several accession and group specific alleles were detected. Similarity coefficients were computed from the molecular data and cluster analyses were performed. Generally, cultivar groups with identical or related common names showed the same SSR patterns or clustered closely together. According to the molecular patterns misleading or confounded names were evident for four accessions. The dendrogram clusters were generally in good agreement with previous classifications of the accessions as Solanum tuberosum subsp. andigena, S. tuberosum subsp. tuberosum and Solanum chaucha genotypes. However in four cases the molecular patterns showed discrepancies with previous species assignments suggesting the need for a more detailed and comparative study of these accessions.

Native potato species (NPS) are cultivated potatoes which do not belong to S. tuberosum ssp. tuberosum. They are maintained by the farmers of the Andes for subsistence under harsh environmental conditions where other potatoes cannot compete. Within the huge phenotypic variability between and within these species certain accessions possess resistances to different pests and diseases, remarkable culinary and processing quality and favourable nutritional properties. We present first evaluation results of a set of NPS for these characters and discuss prospects for exploiting this valuable germplasm for breeding and for developing novel products for niche markets.

DNA markers have a large potential to improve efficiency and precision of conventional plant breeding programmes based on marker‐assisted selection (MAS). In our study, we have evaluated the predictive abilities of the SCAR marker RYSC3 and the CAPS marker GP122564 with regard to the PVY resistance genes Ryadg and Rysto, respectively, and of marker TG689 linked to H1 conferring resistance to Globodera rostochiensis and marker HC associated with high levels of G. pallida resistance. The evaluations were made in 28 cultivars and accessions and in 219 progeny genotypes descending from ten different crosses. We observed in all evaluated cultivars and accessions the expected marker patterns according to their phenotypic classification into resistant and susceptible genotypes. However, in part considerable discrepancies were observed when analysing progeny of controlled crosses involving these resistance sources, particularly with respect to H1. Based on these results, practical aspects for the efficient implementation of marker‐assisted selection are discussed, which consider the genetic origin of the material, costs aspects and methodology applied.