qRfg3, a novel quantitative resistance locus against Gibberella stalk rot in maize

Theor Appl Genet. 2017 Aug;130(8):1723-1734. doi: 10.1007/s00122-017-2921-5. Epub 2017 May 29.

Abstract

A quantitative trait locus qRfg3 imparts recessive resistance to maize Gibberella stalk rot. qRfg3 has been mapped into a 350-kb interval and could reduce the disease severity index by ~26.6%. Gibberella stalk rot, caused by the fungal pathogen Fusarium graminearum, severely affects maize yield and grain quality worldwide. To identify more resistance quantitative trait loci (QTLs) against this disease, we analyzed a recombinant inbred line (RIL) population derived from a cross between resistant H127R and susceptible C7-2 inbred lines. Within this population, maize resistance to Gibberella stalk rot had high broad-sense heritability. A major QTL, qRfg3, on chromosome 3 was consistently detected across three field trials, accounting for 10.7-19.4% of the total phenotypic variation. Using a progeny-based sequential fine-mapping strategy, we narrowed qRfg3 down to an interval of ~350 kb. We further demonstrated that qRfg3 is a recessive resistance locus to Gibberella stalk rot that reduced the disease severity index by ~26.6%. Both the gene location and recessive genetic mode distinguish qRfg3 from other stalk rot resistance loci. Hence, qRfg3 is valuable as a complement to existing resistance QTLs to improve maize resistance to Gibberella stalk rot.

MeSH terms

  • Chromosome Mapping
  • Crosses, Genetic
  • Disease Resistance / genetics*
  • Genetic Linkage
  • Genetic Markers
  • Genotype
  • Gibberella*
  • Phenotype
  • Plant Diseases / genetics*
  • Plant Diseases / microbiology
  • Quantitative Trait Loci*
  • Zea mays / genetics*
  • Zea mays / microbiology

Substances

  • Genetic Markers