title: Gene pyramiding enhances durable blast disease resistance in rice.
abstract: Effective control of blast, a devastating fungal disease of rice, would increase and stabilize worldwide food production. Resistance mediated by quantitative trait loci (QTLs), which usually have smaller individual effects than R-genes but confer broad-spectrum or non-race-specific resistance, is a promising alternative to less durable race-specific resistance for crop improvement, yet evidence that validates the impact of QTL combinations (pyramids) on the durability of plant disease resistance has been lacking. Here, we developed near-isogenic experimental lines representing all possible combinations of four QTL alleles from a durably resistant cultivar. These lines enabled us to evaluate the QTLs singly and in combination in a homogeneous genetic background. We present evidence that pyramiding QTL alleles, each controlling a different response to M. oryzae, confers strong, non-race-specific, environmentally stable resistance to blast disease. Our results suggest that this robust defence system provides durable resistance, thus avoiding an evolutionary "arms race" between a crop and its pathogen.
authors.affiliation: National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Fukuoka
authors.affiliation: Aichi Agricultural Research Center, Mountainous Region Institute, Inahasi, Toyota, Aichi 441-2513, Japan.
authors.forename: Norikuni
authors.initials: N
authors.lastname: Saka
authors.affiliation: Aichi Agricultural Research Center, Mountainous Region Institute, Inahasi, Toyota, Aichi 441-2513, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Mizukami
authors.affiliation: Faculty of Bioresources and Environmental Sciences, Ishikawa Prefectural University, Suematsu 1-308, Nonoichi, Ishikawa 921-8836, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Koga
authors.affiliation: National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Utako
authors.initials: U
authors.lastname: Yamanouchi
authors.affiliation: NARO Institute of Vegetable and Tea Science, 360 Kusawa, Ano, Tsu, Mie 514-2392, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Yoshioka
authors.affiliation: National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Nagao
authors.initials: N
authors.lastname: Hayashi
authors.affiliation: National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Kaworu
authors.initials: K
authors.lastname: Ebana
authors.affiliation: National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Mizobuchi
authors.affiliation: National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yano
mesh_terms: D000483:Alleles; D060467:Disease Resistance / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D020082:Magnaporthe / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D012275:Oryza / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology*; D018515:Plant Leaves / Q000276:immunology / Q000382:microbiology; D040641:Quantitative Trait Loci / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction