Molecular mapping of nuclear male-sterility gene ms-1 in muskmelon (Cucumis melo L.)

ABSTRACT

Five recessive and non-allelic genes, ms-1, ms-2, ms-3, ms-4 and ms-5 possessing unique phenotypes govern male sterility in muskmelon. An inbred MS-1, having recessive ms-1 gene, refined at Punjab Agricultural University, Ludhiana (India) has been successfully utilised for the development of commercial F₁ hybrids. Since the transfer of a recessive gene is tedious and time-consuming, it is very difficult to incorporate the male-terility gene, ms-1 in different backgrounds. The current study was conducted to construct a simple sequence repeat (SSR) marker-based linkage map for ms-1 locus using F₂ population derived from a cross ‘MS-1 // KP₄HM-15ʹ. A total of 506 SSR primer pairs was screened followed by bulked segregant analysis (BSA). Linkage analysis of 150 F₂ plants mapped three SSR markers, DM0187, DM0038 and TJ14 linked to the ms-1 gene on chromosome 6. The marker, DM0187 was closest to the gene at a genetic distance of 4.8 cM. The identified marker can be effectively used to transfer ms-1 gene into elite muskmelon genotypes through marker-assisted backcross breeding, till more tightly linked markers are available. Further, determination of its chromosomal position will be useful for the fine mapping and also provide a basis for cloning of the gene, ms-1.

Abbreviation: BSA, Bulked Segregant Analysis; GMS, Genic Male-Sterility; Logarithm of the Odds, LOD; NMS, Nuclear Male-Sterility; PAGE, Polyacrylamide Gel Electrophoresis; PCR, Polymerase Chain Reaction; RAPD, Random Amplified Polymorphic DNA; SCAR, Sequence Characterized Amplified Region; SSRs, Simple Sequence Repeats

KEYWORDS:

• DNA markers
• genetic male sterility (GMS)
• heterosis breeding
• linkage map
• marker assisted selection
• phenotype prediction

Acknowledgments

The maintenance of breeding material utilised in this study by Dr VK Vashisht, Vegetable Breeder (Retd.), is duly acknowlegded. 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 help from Dr Anu Kalia, EMN Lab. for imaging of flowers is also appreciated. The authors acknowledge the financial support provided by the university.

Disclosure statement

No potential conflict of interest was reported by the authors.