Development of Oriental Melon (Cucumis melo L.)-Derived SSR Markers Using a PCR-Based Method and Polymorphic Application for the Genotyping of Commercial Lines

摘要

The simple sequence repeat (SSR) system is generally regarded as one of the most practical marker systems for the genotyping and variety description of diverse crops. This study was conducted in order to develop Oriental melon-derived SSR markers which could be utilized in the detection of polymorphisms for a variety of commercial C. melo lines. 'Gganchi', a Korean landrace, was employed as a basic material for development. For the isolation of SSR clones, 5' anchored PCR utilizing the degenerate primer, PCT4, and a semi-genomic library construction accommodating the microsatellite-rich PCR profiles were employed. The sequence information was obtained from the primary SSR clones, and gene-specific primers (GSP1) were developed for terminal microsatellites harboring more than eight repeat units. A chromosome-walking procedure was followed in an effort to develop another gene-specific primer (GSP3) on the opposite side of the target microsatellites. Eventually, both locus-specific primers were constructed for the 16 contiged SSR clones. Among these, the unique polymorphism was observed in 7 of the primer sets. The observation of polymorphisms was extended to 44 C. melo accessions, including both types of Oriental melon and western cultivars, therebyindicating the specificity of the developed primer sets at the given SSR loci, as well as the general utility of the markers for the genetic evaluation of a variety of melon accession types.