title: The effect of pyramiding Phytophthora infestans resistance genes R Pi-mcd1 and R Pi-ber in potato.
abstract: Despite efforts to control late blight in potatoes by introducing R(pi)-genes from wild species into cultivated potato, there are still concerns regarding the durability and level of resistance. Pyramiding R(pi)-genes can be a solution to increase both durability and level of resistance. In this study, two resistance genes, R(Pi-mcd1) and R(Pi-ber), introgressed from the wild tuber-bearing potato species Solanum microdontum and S. berthaultii were combined in a diploid S. tuberosum population. Individual genotypes from this population were classified after four groups, carrying no R(pi)-gene, with only R (Pi-mcd1), with only R(Pi-ber), and a group with the pyramided R(Pi-mcd1) and R (Pi-ber) by means of tightly linked molecular markers. The levels of resistance between the groups were compared in a field experiment in 2007. The group with R(Pi-mcd1) showed a significant delay to reach 50% infection of the leaf area of 3 days. The group with R ( Pi-ber ) showed a delay of 3 weeks. The resistance level in the pyramid group suggested an additive effect of R (Pi-mcd1) with R(Pi-ber). This suggests that potato breeding can benefit from combining individual R(pi)-genes, irrespective of the weak effect of R(Pi-mcd1) or the strong effect of R(Pi-ber).
authors.affiliation: Laboratory of Plant Breeding, Wageningen University and Research Centre, P.O. Box 386, 6700 AJ, Wageningen, The Netherlands.
authors.forename: M Y Adillah
authors.initials: MY
authors.lastname: Tan
authors.forename: Ronald C B
authors.initials: RC
authors.lastname: Hutten
authors.forename: Richard G F
authors.initials: RG
authors.lastname: Visser
authors.forename: Herman J
authors.initials: HJ
authors.lastname: van Eck
mesh_terms: D001947:Breeding; D018556:Crops, Agricultural / Q000235:genetics / Q000382:microbiology; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D007113:Immunity, Innate / Q000235:genetics*; D008969:Molecular Sequence Data; D055750:Phytophthora infestans / Q000276:immunology* / Q000472:pathogenicity; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D011198:Solanum tuberosum / Q000235:genetics / Q000382:microbiology
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers