FIGURE 4.

Map-based cloning of scp-1 locus. Initial framework mapping with 46 F₂ plants identified 11 SSR markers linked with scp-1 in cucumber Chromosome 5 (A). Linkage analysis with new markers in 184 F2 plants delimits the scp-1 locus between SSR31415 and UW050632 (B). SNP index plot shows possibly harboring causal mutations in chromosome 5 for C257 using MutMap. Red regression lines were obtained by averaging SNP indices from a moving window of five consecutive SNPs and shifting the window one SNP at a time. The x-axis value of each averaged SNP index was set at a midpoint between the first and fifth SNP (C). Fourteen SNPs located in eight gene exon region were extracted. Green swallowtails and black arrows indicate genes and mutation sites, respectively (D). The candidate gene encodes a putative cytochrome P450 protein CsCYP85A1 which has nine exons and eight introns. The SNP in the second exon results in a tryptophan codon at 157 position (TGG) substitution to a stop codon (TAG). Blue rectangles with consecutive numbers and black line indicate exons and introns, respectively. Mutation identified in C257 are indicated (E).