Abstract: FLC2 gene is a key gene affecting the bolting and flowering and plays an important role in the process of transition from vegetative growth to flower development in cruciferous plants. In order to breed a late-bolting green radish cultivar suitable for early spring cultivation, based on the function of FLC2 gene effecting the bolting, the late bolting radish variety Baiyuchun was used as the donor to transfer the late bolting character to Weifang radish by backcross breeding, and the polymorphism of FLC2 was studied during the process of backcross breeding to explore the effects of FLC2 in late bolting radish breeding. The results showed that the first intron of FLC2 gene had an insertion mutation with a length of about 1 628 bp in the late bolting donor, which was important for late bolting, and the homozygous insertion mutation had greater effect on late bolting than the heterozygous type did. It was found that the length of vernalization period affected the PCR amplification results on the first intron of FLC2. The short-term vernalization mainly affected the amplification of the first intron of the wild type FLC2, and the long-term vernalization mainly affected the amplification of intron in the insertion mutant, while the amplification of the two genotypes in the bolting and flowering period was not affected greatly. The amplification efficiency could be improved by improving the primers, but it could not eliminate the effect of vernalization on the first intron amplification of FLC2. The PCR result of normal plants at seedling stage was not as good as that at bolting stage. In conclusion, late bolting trait could be transfer into the acceptor radish by backcross continuously. When the heterozygous genotype was created by backcrossing, it could transfer the gene to its offsprings, and then the homozygous genotype could be obtained by self-crossing. The homozygous mutants with FLC2 insertion sequence could be confirmed by PCR detection at flowering stage, which could ensure the genetic stability and avoid the separation of late bolting traits in the offsprings.

Key words: Radish, Late bolting, First intron of FLC2, Vernalization, Backcross

CLC Number: 

• S631.03

• Q78