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.

KEYWORDS:

• Bulked segregant analysis
• Fom gene
• snapmelon
• internal transcribed regions
• muskmelon
• wilt resistance

Acknowledgments

The contributions in the development and maintenance of breeding material utilised in this study by Dr V.K. Vashisht and Dr T. Lal, Vegetable Breeders (Retd) are duly acknowledged. The authors are also thankful to the team of Cucurbit Genome Database for utilising the information about a set of SSR primers in this study. The authors acknowledge the financial support provided by the Punjab Agricultural University, Ludhiana.

Disclosure statement

No potential conflict of interest was reported by the author(s).