title: Fine-mapping of qRfg2, a QTL for resistance to Gibberella stalk rot in maize.
abstract: Stalk rot is one of the most devastating diseases in maize worldwide. In our previous study, two QTLs, a major qRfg1 and a minor qRfg2, were identified in the resistant inbred line '1145' to confer resistance to Gibberella stalk rot. In the present study, we report on fine-mapping of the minor qRfg2 that is located on chromosome 1 and account for ~8.9% of the total phenotypic variation. A total of 22 markers were developed in the qRfg2 region to resolve recombinants. The progeny-test mapping strategy was developed to accurately determine the phenotypes of all recombinants for fine-mapping of the qRfg2 locus. This fine-mapping process was performed from BC(4)F(1) to BC(8)F(1) generations to narrow down the qRfg2 locus into ~300 kb, flanked by the markers SSRZ319 and CAPSZ459. A predicted gene in the mapped region, coding for an auxin-regulated protein, is believed to be a candidate for qRfg2. The qRfg2 locus could steadily increase the resistance percentage by ~12% across different backcross generations, suggesting its usefulness in enhancing maize resistance against Gibberella stalk rot.
authors: National Maize Improvement Center of China, China Agricultural University, 2 West Yuanmingyuan Road, Beijing, 100193, People's Republic of China.
authors: Dongfeng
authors: D
authors: Zhang
authors: Yongjie
authors: Y
authors: Liu
authors: Yanling
authors: Y
authors: Guo
authors: Qin
authors: Q
authors: Yang
authors: Jianrong
authors: J
authors: Ye
authors: Shaojiang
authors: S
authors: Chen
authors: Mingliang
authors: M
authors: Xu
mesh_terms: D001947:Breeding / Q000379:methods*; D002874:Chromosome Mapping; D017931:DNA Primers / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics; D005838:Genotype; D005874:Gibberella; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology*; D040641:Quantitative Trait Loci / Q000235:genetics*; D003313:Zea mays / Q000235:genetics* / Q000382:microbiology
chemical_list: D017931:DNA Primers; D005819:Genetic Markers