Molecular Characterization of Resistance to Soybean Rust (Phakopsora pachyrhizi Syd. & Syd.) in Soybean Cultivar DT 2000 (PI 635999)

PLoS One. 2016 Dec 9;11(12):e0164493. doi: 10.1371/journal.pone.0164493. eCollection 2016.

Abstract

Resistance to soybean rust (SBR), caused by Phakopsora pachyrhizi Syd. & Syd., has been identified in many soybean germplasm accessions and is conferred by either dominant or recessive genes that have been mapped to six independent loci (Rpp1 -Rpp6), but No U.S. cultivars are resistant to SBR. The cultivar DT 2000 (PI 635999) has resistance to P. pachyrhizi isolates and field populations from the United States as well as Vietnam. A F6:7 recombinant inbred line (RIL) population derived from Williams 82 × DT 2000 was used to identify genomic regions associated with resistance to SBR in the field in Ha Noi, Vietnam, and in Quincy, Florida, in 2008. Bulked segregant analysis (BSA) was conducted using the soybean single nucleotide polymorphism (SNP) USLP 1.0 panel along with simple sequence repeat (SSR) markers to detect regions of the genome associated with resistance. BSA identified four BARC_SNP markers near the Rpp3 locus on chromosome (Chr.) 6. Genetic analysis identified an additional genomic region around the Rpp4 locus on Chr. 18 that was significantly associated with variation in the area under disease progress curve (AUDPC) values and sporulation in Vietnam. Molecular markers tightly linked to the DT 2000 resistance alleles on Chrs. 6 and 18 will be useful for marker-assisted selection and backcrossing in order to pyramid these genes with other available SBR resistance genes to develop new varieties with enhanced and durable resistance to SBR.

MeSH terms

  • Alleles
  • Chromosome Mapping
  • Chromosomes, Plant / chemistry*
  • Disease Resistance / genetics
  • Genetic Loci
  • Genetic Markers / immunology
  • Genome, Plant*
  • Genotype
  • Glycine max / genetics*
  • Glycine max / immunology
  • Glycine max / microbiology
  • Microsatellite Repeats / immunology
  • Phakopsora pachyrhizi / pathogenicity
  • Phakopsora pachyrhizi / physiology*
  • Plant Diseases / genetics*
  • Plant Diseases / immunology
  • Plant Diseases / microbiology
  • Polymorphism, Single Nucleotide
  • Spores, Fungal / pathogenicity
  • Spores, Fungal / physiology*

Substances

  • Genetic Markers

Grants and funding

This study was partially funded by the United Soybean Board [http://unitedsoybean.org/] as a part of the project “Identification and utilization of resistance to soybean rust” (USB # 1235) and by the National Center for Soybean Biotechnology (USDA-CSREES Award No. 2008-34555-19305). The United Soybean Board had read the manuscript and has indicted their approval of the manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.