title: High-resolution mapping and characterization of qRgls2, a major quantitative trait locus involved in maize resistance to gray leaf spot.
abstract: BACKGROUND
  Gray leaf spot (GLS) caused by Cercospora zeae-maydis (Czm) or Cercospora zeina (Cz) is a devastating maize disease and results in substantial yield reductions worldwide. GLS resistance is a quantitatively inherited trait. The development and cultivation of GLS-resistant maize hybrids are the most cost-effective and efficient ways to control this disease.
  
  
  RESULTS
  We previously detected a major GLS resistance QTL, qRgls2, in bin 5.03-04, which spans the whole centromere of chromosome 5 encompassing a physical distance of ~110-Mb. With advanced backcross populations derived from the cross between the resistant Y32 and susceptible Q11 inbred lines, a sequential recombinant-derived progeny testing strategy was adapted to fine map qRgls2. We narrowed the region of qRgls2 from an initial ~110-Mb to an interval of ~1-Mb, flanked by the markers G346 and DD11. qRgls2 showed predominantly additive genetic effects and significantly increased the resistance percentage by 20.6 to 24.6% across multiple generations. A total of 15 genes were predicted in the mapped region according to the 5b.60 annotation of the maize B73 genome v2. Two pieces of the mapped qRgls2 region shared collinearity with two distant segments on maize chromosome 4.
  
  
  CONCLUSIONS
  qRgls2, a major QTL involved in GLS resistance, was mapped to a ~1-Mb region close to the centromere of chromosome 5. There are 15 predicted genes in the mapped region. It is assumed that qRgls2 could be widely used to improve maize resistance to GLS.
authors.forename: Ling
authors.initials: L
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Siquan
authors.initials: S
authors.lastname: Shao
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Tan
authors.forename: Mang
authors.initials: M
authors.lastname: Zhu
authors.forename: Tao
authors.initials: T
authors.lastname: Zhong
authors.forename: Xingming
authors.initials: X
authors.lastname: Fan
authors.forename: Mingliang
authors.initials: M
authors.lastname: Xu
mesh_terms: D001203:Ascomycota / Q000502:physiology*; D060467:Disease Resistance / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology; D040641:Quantitative Trait Loci / Q000235:genetics*; D003313:Zea mays / Q000235:genetics* / Q000382:microbiology*