Characterization of Fusarium race 1.2 resistance in melon and mapping of a major QTL for this trait near a fruit netting locus

An Israeli breeding line, BIZ, resistant to all four races of Fusarium oxysporum f.sp. melonis (FOM), has been characterized regarding its response to FOM race 1.2. The infection process of a FOM 1.2 strain that expresses the GFP reporter protein was monitored, suggesting the timing and sites in which fungal progression differs between a resistant and a susceptible genotype. A mapping population derived from the cross PI 414723 and BIZ was used to construct a linkage map with ~90 traits and markers, and QTL analysis of FOM1.2 resistance was initiated. Other traits such as flesh color and rind netting were mapped as well. A major recessive QTL for FOM1.2 resistance was located in linkage group 2, near a major locus controlling net development.