Characterization of Fusarium race 1.2 resistance in melon and mapping of a major QTL for this trait near a fruit netting locus 1

An Israeli breeding line, BIZ, resistant to all fou r races of Fusarium oxysporum f.sp. melonis (FOM), has been characterized regarding its respon se to FOM race 1.2. The infection process of a FOM 1.2 strain that expr esses the GFP reporter protein was monitored, suggesting the timing and sites in which fungal progression differs between a resistant and a susceptible genotype. A m apping 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 m ajor locus controlling net development.