QTL validation via systematic development of near-isogenic wheat lines from existing breeding populations.

摘要

The objectives of this research were to develop QTL near-isogenic lines (NILs) for a major Fusarium head blight (FHB) resistance QTL, Qfhs.ndsu-3BS, and determine if this QTL consistently enhances FHB resistance across multiple wheat genetic backgrounds. Microsatellite markers flanking the QTL region were selected to develop 30 QTL-NIL pairs from 16 different genetic backgrounds. Each pair was tested in point-inoculation experiments and field FHB resistance screening nurseries. Across point-inoculation experiments, 11 of the 16 different populations had at least one QTL-NIL pair with significantly reduced disease spread. In two field FHB screening nurseries, Qfhs.ndsu-3BS significantly reduced disease severity and percentage of visually scabby kernels in harvested grain samples by an average of 21 and 24%, respectively. The combination of field and point-inoculation results indicates that Qfhs.ndsu-3BS should enhance FHB resistance largely independent of genetic background. Furthermore, the outlined QTL validation methodology should be broadly applicable to other traits and crop species.