Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/1998
Publication Date: N/A
Interpretive Summary: Fusarium wilt is a devastating fungal disease of melons throughout the world. The only effective way to control the disease is through the use of resistant varieties of melon. Currently, development of these varieties in a breeding program is made very complicated and time consuming because of the necessity to artificially inoculate each plant in the program so as to identify those that are genetically resistant to the disease. The use of molecular markers to identify those plants that carry the genes for resistance to the disease would make the breeding and selection process more efficient. In the present work, molecular markers were developed that accurately identify resistant plants. These markers can be used to identify resistant plants and eliminate the current requirement for artificial inoculations. The use of these markers in breeding programs will improve the accuracy and efficiency of these programs in the development of Fusarium wilt resistant melon varieties.
Technical Abstract: Fusarium wilt caused by Fusarium oxysporum f.sp. melonis is one of the most devastating diseases in melon production worldwide. Resistant varieties are the only efficient control measures for this soil-borne pathogen. Tagging resistance genes with molecular markers facilitates the cloning of the gene and marker-assisted selection in a breeding program targeted at development of these resistant varieties. Resistant and susceptible bulks constructed from F2 progenies of resistant x susceptible parents were screened using AFLP techniques with PstI/MseI and EcoRI/MseI primer combinations. Markers potentially linked to Fom-2 (responsible for resistance to races 0 and 1 of the fungus) have been identified and mapped relative to the gene. Based on the mapping population a RAPD marker was found to cosegregate with the gene and other two AFLP markers flanked Fom-2. A survey of diverse melon genotypes showed that these markers can be used to predict resistant phenotypes. The markers are being converted to codominant PCR markers for easier use in a breeding and selection program.