Resistance to Fusarium head blight in wheat: molecular mapping and validation of QTLs for horizontal resistance, implications for resistance breeding

摘要

Fusarium head blight (FHB) is a cereal disease leading to yield losses and, more importantly, quality losses due to mycotoxin contamination. A doubled haploid population derived from the cross CM-82036/Remus was extensively evaluated in field experiments artificially inoculated with two Fusarium species. Resistance to fungal spread was measured by single-spikelet inoculations and resistance to penetration and spread by spray inoculations. A molecular linkage map was produced which enabled us to map of two major QTLs for horizontal FHB resistance: Ofhs.ndsu-3BS and Qfhs.ifa-SA. In order to assess the non-specific or horizontal nature of the identified QTLs in more detail we evaluated a subset of 96 doubled haploid lines from the CM-82036/Remus population by inoculation with eight isolates from four Fusarium species and Microdochium nivale. Results indicate that resistance was horizontal to all tested isolates so far. Marker assisted selection for FHB resistance is feasible and should lead to a significant improvement in horizontal FHB resistance.