title: A Novel Phytophthora sojae Resistance Rps12 Gene Mapped to a Genomic Region That Contains Several Rps Genes.
abstract: Phytophthora sojae Kaufmann and Gerdemann, which causes Phytophthora root rot, is a widespread pathogen that limits soybean production worldwide. Development of Phytophthora resistant cultivars carrying Phytophthora resistance Rps genes is a cost-effective approach in controlling this disease. For this mapping study of a novel Rps gene, 290 recombinant inbred lines (RILs) (F7 families) were developed by crossing the P. sojae resistant cultivar PI399036 with the P. sojae susceptible AR2 line, and were phenotyped for responses to a mixture of three P. sojae isolates that overcome most of the known Rps genes. Of these 290 RILs, 130 were homozygous resistant, 12 heterzygous and segregating for Phytophthora resistance, and 148 were recessive homozygous and susceptible. From this population, 59 RILs homozygous for Phytophthora sojae resistance and 61 susceptible to a mixture of P. sojae isolates R17 and Val12-11 or P7074 that overcome resistance encoded by known Rps genes mapped to Chromosome 18 were selected for mapping novel Rps gene. A single gene accounted for the 1:1 segregation of resistance and susceptibility among the RILs. The gene encoding the Phytophthora resistance mapped to a 5.8 cM interval between the SSR markers BARCSOYSSR_18_1840 and Sat_064 located in the lower arm of Chromosome 18. The gene is mapped 2.2 cM proximal to the NBSRps4/6-like sequence that was reported to co-segregate with the Phytophthora resistance genes Rps4 and Rps6. The gene is mapped to a highly recombinogenic, gene-rich genomic region carrying several nucleotide binding site-leucine rich repeat (NBS-LRR)-like genes. We named this novel gene as Rps12, which is expected to be an invaluable resource in breeding soybeans for Phytophthora resistance.
authors.affiliation: Department of Agronomy, Iowa State University, Ames, IA, United States of America.
authors.forename: Dipak K
authors.initials: DK
authors.lastname: Sahoo
authors.affiliation: Department Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States of America.
authors.forename: Nilwala S
authors.initials: NS
authors.lastname: Abeysekara
authors.affiliation: Department of Agronomy, Iowa State University, Ames, IA, United States of America.
authors.forename: Silvia R
authors.initials: SR
authors.lastname: Cianzio
authors.affiliation: Department Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States of America.
authors.forename: Alison E
authors.initials: AE
authors.lastname: Robertson
authors.affiliation: Department of Agronomy, Iowa State University, Ames, IA, United States of America.
authors.forename: Madan K
authors.identifier: http://orcid.org/0000-0002-5639-9706
authors.initials: MK
authors.lastname: Bhattacharyya
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000302:isolation & purification / Q000378:metabolism; D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D018895:Microsatellite Repeats / Q000235:genetics; D008969:Molecular Sequence Data; D010641:Phenotype; D010838:Phytophthora / Q000302:isolation & purification / Q000502:physiology*; D010935:Plant Diseases / Q000235:genetics / Q000469:parasitology; D010940:Plant Proteins / Q000235:genetics; D018517:Plant Roots / Q000469:parasitology; D013025:Glycine max / Q000235:genetics* / Q000254:growth & development / Q000469:parasitology
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins