A F₂ population of radish （Raphanus sativus L.） was constructed by crossing the lobed-leaf cultivar J4 with the serrated-leaf cultivar WA.Two bulk DNA samples consisted of equivalent amounts of DNA from 20 individuals with lobed-leaf and 20 individuals with serrated-leaf in the F₂ population were used to study the inheritance of the lobed-leaf in radish.The results showed that the leaf in radish was controlled by a single gene.The lobed-leaf is incomplete dominant over the serrated-leaf.The gene for lobed-leaf was initially mapped to the genomic region from 0.07 Mb to 7.97 Mb on chromosome R7 through bulked segregant analysis （BSA） and genotyping by sequencing （GBS）.It was found that there is good collinearity between 0.87-1.32 Mb in the candidate interval of radish and 16.35-16.80 Mb of the A10 chromosome of rapeseed by analyzing the collinearity between the whole genome of radish and rapeseed（Brassica napus）.Gene function annotation of the collinear segment confirmed that Rs390250（899 863-901 651 bp） is a candidate gene of lobed-leaf in radish.This candidate gene encodes a HD-ZipⅠ （the class Ⅰ homeodomain leucine-zipper） transcription factor.Its non-synonymous mutation site T425C located in the 2nd exon leads to changes in conserved amino acids in the LZ （leucine zipper） domain，indicating that it may be a key site for the variation of leaf morphology.