摘要： FLC2基因作为影响成花的关键枢纽基因，在十字花科植物成花转变过程中具有重要作用。为了培育适于早春栽培的晚抽薹青萝卜新品种，在充分考虑FLC2基因对抽薹开花作用的基础上，以晚抽薹基因型白玉春萝卜为供体，通过回交转育的方法将晚抽薹性状转移到潍县青萝卜中，并在转育过程中对FLC2扩增多态性进行了研究，以探索晚抽薹植株FLC2的特征，并开发其对早春品种选育的作用。结果表明：FLC2第1内含子在晚抽薹供体中具有长约1 628 bp的插入突变，该基因型对晚抽薹作用较大，纯合的插入突变对晚抽薹作用大于杂合型。通过对该插入突变的PCR扩增可知，不同春化时期对插入突变内含子扩增的影响不同，短期春化主要影响野生型FLC2第1内含子的扩增，较长时间的春化主要影响插入突变内含子的扩增，而在抽薹开花期2种基因型的扩增基本不受影响，扩增效率高。通过改进引物，可以提高扩增效率，但不能消除春化对FLC2第1内含子扩增的影响，苗期未经春化植株不及抽薹开花期检测效果好。萝卜晚抽薹回交转育可以连续进行，每次转育只要获得杂合基因型即可传递晚抽薹性状，最后的自交后代，通过花期对插入突变内含子的PCR检测可以准确鉴定植株是否为纯合突变型晚抽薹植株，获得遗传稳定的晚抽薹基因型，从而可防止后代晚抽薹性状的分离。

关键词: 萝卜, 晚抽薹, FLC2第1内含子, 春化, 回交

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

中图分类号: 

• S631.03

• Q78