Abstract: Bolting time of 16 Brassica rapa accessions were investigated under artificial vernalization treatment. The result showed that there was a wide range variation of bolting time among these accessions. Polymerase Chain reaction (PCR) with a primer pair based on the BrFLC1 gene sequence generated a 980 bp fragment from all accessions. A base variation located at P3 was significantly associated with bolting time, and the base variation at this position is the recognition site of restriction enzyme Mva I. Therefore, a Cleaved Amplified Polymorphic Sequnence (CAPS) marker designated as G-Mva I was developed for this locus by digesting the amplified fragment with Mva I. The marker was verified in 96 B. rapa DH lines, displaying a significant association between the bolting phenotypes and the genotypes of G- Mva I. These results indicated that G-Mva I can be easily used for marker-assisted selection (MAS) in late bolting or bolting-resistance breeding.

Key words: Brassica rapa L.syn campestris L, bolting, BrFLC1 gene, CAPS marker