Functional Interactions Between Major Rice Blast Resistance Genes, Pi-ta and Pi-b, and Minor Blast Resistance Quantitative Trait Loci

• DOI: 10.1094/phyto-02-18-0032-r
• Publication Date: 2018-04-16T13:31:29Z
• Authors: Xinglong Chen; Yulin Jia; Melissa H. Jia; Shannon R. M. Pinson; Xueyan Wang; B. M. Wu
• Keywords: R gene; Genetic linkage; Epistasis; Inbred strain

Major blast resistance (R) genes confer in a gene-for-gene manner. However, little information is available on interactions between R genes. In this study, two rice genes, Pi-ta and Pi-b, other minor quantitative trait loci (QTLs) were investigated recombinant inbred line (RIL) population comprising 243 RILs from Cybonnet (CYBT) × Saber (SB) cross. CYBT has the gene SB Pi-b. Ten differential isolates of four Magnaporthe oryzae races (IB-1, IB-17, IB-49, IE-1K) used to evaluate disease reactions under greenhouse conditions. Five QTLs mapped chromosomes 2, 3, 8, 9, 12 with linkage map 179 single nucleotide polymorphism markers. Among them, qBR12 (Q1), was at locus accounted for 45.41% phenotypic variation while qBR2 (Q2) located Pi-b 24.81% reactions. The additive-by-additive epistatic interaction Q1 (Pi-ta) Q2 (Pi-b) detected; they can enhance by an additive 0.93 using 0 9 standard phenotyping method. These results suggest that interacts synergistically