Detection of Novel QTLs for Late Blight Resistance Derived from the Wild Potato Species Solanum microdontum and Solanum pampasense

• Published in: Genes Vol. 11; no. 7; p. 732
• Main Authors: Meade, Fergus, Hutten, Ronald, Wagener, Silke, Prigge, Vanessa, Dalton, Emmet, Kirk, Hanne Grethe, Griffin, Denis, Milbourne, Dan
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30.06.2020; MDPI
• Subjects: Breeding; Chromosome 10; Chromosomes, Plant - genetics; Cloning; Disease Resistance; Gene clusters; Gene mapping; Gene polymorphism; Genes; Genotype & phenotype; Late blight; Marker-assisted selection; Pathogens; Phenotypic variations; Phytophthora - pathogenicity; Plant Breeding - methods; Polymorphism, Single Nucleotide; Population; Population studies; Quantitative Trait Loci; Single-nucleotide polymorphism; Solanum; Solanum - genetics; Solanum - immunology; Solanum - microbiology; Species; Sprinkler systems; Argentina; Germany; Phytophthora infestans; QTL; marker-assisted selection; late blight; potato; breeding
• ISSN: 2073-4425; 2073-4425
• DOI: 10.3390/genes11070732

Wild potato species continue to be a rich source of genes for resistance to late blight in potato breeding. Whilst many dominant resistance genes from such sources have been characterised and used in breeding, quantitative resistance also offers potential for breeding when the loci underlying the resistance can be identified and tagged using molecular markers. In this study, F populations were created from crosses between blight susceptible parents and lines exhibiting strong partial resistance to late blight derived from the South American wild species and . Both populations exhibited continuous variation for resistance to late blight over multiple field-testing seasons. High density genetic maps were created using single nucleotide polymorphism (SNP) markers, enabling mapping of quantitative trait loci (QTLs) for late blight resistance that were consistently expressed over multiple years in both populations. In the population created with the source, QTLs for resistance consistently expressed over three years and explaining a large portion (21-47%) of the phenotypic variation were found on chromosomes 5 and 6, and a further resistance QTL on chromosome 10, apparently related to foliar development, was discovered in 2016 only. In the population created with the source, QTLs for resistance were found in over two years on chromosomes 11 and 12. For all loci detected consistently across years, the QTLs span known R gene clusters and so they likely represent novel late blight resistance genes. Simple genetic models following the effect of the presence or absence of SNPs associated with consistently effective loci in both populations demonstrated that marker assisted selection (MAS) strategies to introgress and pyramid these loci have potential in resistance breeding strategies.