Construction of a high-density DArTseq SNP-based genetic map and identification of genomic regions with segregation distortion in a genetic population derived from a cross between feral and cultivated-type watermelon

Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] is an economically important vegetable crop grown extensively worldwide. To facilitate the identification of agronomically important traits and provide new information for genetic and genomic research on this species, a high-density genetic linkage map of watermelon was constructed using an F2 population derived from a cross between elite watermelon cultivar K3 and wild watermelon germplasm PI 189225. Based on a sliding window approach, a total of 1,161 bin markers representing 3,465 SNP markers were mapped onto 11 linkage groups corresponding to the chromosome pair number of watermelon. The total length of the genetic map is 1,099.2cM, with an average distance between bins of 1.0cM. The number of markers in each chromosome varies from 62 in chromosome 07 to 160 in chromosome 05. The length of individual chromosomes ranged between 61.8cM for chromosome 07 and 140.2cM for chromosome 05. A total of 616 SNP bin markers showed significant (P