Genome-wide association analysis reveals a novel QTL CsPC1 for pericarp color in cucumber

Background Cucumber is an important melon crop in the world, with different pericarp colors. However, the candidate genes and the underlying genetic mechanism for such an important trait in cucumber are unknown. In this study, a locus controlling pericarp color was found on chromosome 3 of cucumber genome. Results In this study, the light green inbred line G35 and the dark green inbred line Q51 were crossed to produce one F-2 population. Consequently, we identified a major locus CsPC1 (Pericarp color 1). Next, we mapped the CsPC1 locus to a 94-kb region chromosome 3 which contains 15 genes. Among these genes, Csa3G912920, which encodes a GATA transcription factor, was expressed at a higher level in the pericarp of the NIL-1334 line (with light-green pericarp) than in that of the NIL-1325 line (with dark-green pericarp). This study provides a new allele for the improvement of cucumber pericarp color. Conclusion A major QTL that controls pericarp color in cucumber, CsPC1, was identified in a 94-kb region that harbors the strong candidate gene CsGATA1.