Inheritance analysis and identification of SSR markers associated with fusarium wilt resistance in melon

Abstract

Fusarium wilt (FW), caused by Fusarium oxysporum Schlechtend f. sp. melonis (Leach & Currence) Snyd. & Hans (Fom) is a substantial threat to muskmelon (Cucumis meloL.) cultivation around the world. Identification of new sources of resistance and transfer of the resistance genes to elite cultivars is the effective breeding strategy to reduce the FW-associated crop losses in muskmelon. In the present study, inheritance studies and molecular mapping for FW resistance were conducted in a muskmelon inbred line KP4HM-15 with FW resistance introgressed from snapmelon. Inheritance studies in the F2 population derived from the cross Punjab Sunehri//KP4HM-15 indicated that FW resistance in KP4HM-15 is governed by a single dominant gene. Bulked segregant analysis was conducted to map the Fom-5(t) gene in KP4HM-15 using 527 SSR primers. Four primer pairs, CMCTN35, DM0096, CSWCTT02, and ECM181, were found to show differential polymorphism in the resistant and susceptible bulks and were analysed in the whole of the population. Two SSR markers, DM0096 and CSWCTT02, mapped close to the Fom-5(t) gene at a genetic distance of 1.4 and 2.5 cM, respectively. These markers can potentially be used to transfer Fom-5(t) in elite muskmelon genotypes through marker-assisted backcross breeding until more tightly linked markers are available.