A linkage map of cultivated cucumber (Cucumis sativus L.) with 248 microsatellite marker loci and seven genes for horticulturally important traits

A genetic map was developed with microsatellite (simple sequence repeat, SSR) markers and 148 recombinant inbred lines (RILs) derived from a cross between two cultivated cucumber (Cucumis sativus L.) inbred lines 9110Gt and 9930, which was also segregating for seven horticulturally important traits including bitterfree foliage (bi), gynoecious sex expression (F), uniform immature fruit color (u), glossy fruit skin (d), heavy netting of mature fruit (H), no fruit ribbing (fr), and virescent leaf (v-1). Linkage analysis placed 248 microsatellite loci into seven linkage groups spanning 711.9 cM with a mean marker interval of 2.8 cM. Based on shared markers with an early cucumber genetic map, the 7 linkage groups could be assigned to seven cucumber chromosomes. The four fruit epidermal feature-related genes, u, d, H and fr were found to be tightly linked loci in Chromosome 5, and the other three (F, bi and v-1) were placed in different locations of Chromosome 6. It was the first time to map the four genes H, fr, bi and v-1 with molecular markers. In addition, this is the first report of the inheritance of fruit ribbing in cucumber, which was controlled by a single, dominant gene designated as Fr. Mapping information from this study opens the way for marker-assisted selection and map-based cloning of these horticulturally important genes in cucumber.