Bulked Segregant Analysis Revealed the Common Resistant QTLs Associated with Fusarium Ear Rot and Gibberella Ear Rot...

Maize ear rot, primarily caused by Fusarium verticillioides (Fusarium ear rot, FER) and Fusarium graminearum (Gibberella ear rot, GER), is a devastating disease that causes significant yield losses and mycotoxin contamination. Breeding resistant varieties is the most effective control strategy, but this requires the identification of stable genetic loci for resistance. In this study, we employed bulked segregant analysis (BSA) on two F₂ mapping populations to identify quantitative trait loci (QTLs) conferring resistance to FER and GER. We identified five and eleven QTLs for FER and GER, respectively. Notably, chromosome 4 was identified as a major hotspot for resistance to both diseases, and there was a co-localization of the FER QTL (qFER4.05) and GER QTL (qGER4.05-1) within a 58.58-71.34 Mb interval on bin 4.05, suggesting a potential locus for broad-spectrum resistance. Within this overlapping region, we identified 18 high-confidence candidate genes, including genes encoding leucine-rich repeat receptor-like kinases (LRR-RLKs), remorin, cytochrome P450 monooxygenases, and wall-associated receptor kinase-like (WAKL) protein, all with established roles in plant defense. These findings advance the understanding of the genetic architecture of ear rot resistance and provide critical resources for marker-assisted breeding to develop maize hybrids with durable resistance to both FER and GER.