Fine mapping of a Phytophthora-resistance locus RpsGZ in soybean using Genotyping-by-Sequencing

Abstract Background Phytophthora root rot (PRR), caused by Phytophthora sojae is one of the most important soil-borne diseases in many soybean-production regions in the world. Identification of resistant gene(s) and incorporating them into elite varieties are an effective way for breeding to prevent soybean from being harmed by this disease. A valuable mapping population of 228 F8:11 recombinant inbred lines (RILs) derived from a cross of resistant cultivar Guizao1 and susceptible cultivar BRSMG68 and a high-density genetic linkage map with an average distance of 0.81 centimorgan (cM) between adjacent bin markers in this population were used to map and explore the candidate genes. Results In this study, the PRR resistance in Guizao1 was controlled by a single Mendelian locus, and was fine mapped to a 460.702-kb genomic region on chromosome 3 that harbours 20 genes, including 8 disease resistance (R)-like genes in the reference Willliams 82 genome. These 8 candidate genes potentially involved in programmed cell death, cell death, apoptosis and ADP binding by adopting Gene Ontology (GO) enrichment analysis. Conclusions These findings of fine mapping of a novel Rps locus will serve as a basis for cloning, transferring of resistant genes and breeding of P. sojae resistant soybean cultivars through marker-assisted selection.