Development of new DNA markers linked to the Fusarium wilt resistance locus Fom-1 in melon

With 5 figures and 2 tables Abstract Use of resistance genes would be the most effective way to address Fusarium wilt caused by Fusarium oxysporum f.sp. melonis in melon. In this study, based on the BAC 31O16 sequence which contains the cluster of melon resistance gene homologue, we developed four new DNA markers linked to Fom-1, a dominant resistance gene against F. oxysporum f.sp. melonis races 0 and 2. Linkage analysis using 125 F2 plants derived from the cross between P11 (fom-1fom-1) and MR-1 (Fom-1Fom-1) indicated that Fom-1 was located between CAPS markers C-MRGH12 and 62-CAPS at a distance of 0.4 and 1.2 cM, respectively. Map position of Fom-1 was confirmed using another mapping population consisting of 104 recombinant inbred lines derived from the cross P11 × MR-1. The analysis of 43 fixed lines and 27 commercial F1 hybrids showed that the developed DNA markers linked to Fom-1 correctly predicted the genotype in relation to the variety, suggesting that the region around the Fom-1 locus is very polymorphic or there is no linkage disequilibrium between the locus and the marker loci.