FLOWERING LOCUS C(FLC)encodes MADS-box family protein and plays a key role in the vernalization pathway of Arabidopsis.To explore the role of BoFLCs in the vernalization pathway of cabbage,we knocked out BoFLCs in cabbage inbred line'GL'by CRISPR/Cas9.All the knock-out lines had significantly earlier flowering time,providing insight into the function of BoFLCs gene.The BC1-2P2 and BC2F1 segregating populations were constructed using late-flowering cabbage inbred line'20-2221'(P1,BoFLCs-w)and mid-early-flowering cabbage inbred line'20-2229'(P2,BoFLCs-z).Sequence analysis showed that BoFLC1,BoFLC3 and BoFLC5 had sequence differences between parents,and specific molecular markers were developed based on these sequence differences.The BC2F1 population was screened by the BoFLCs specific molecular markers.One plant containing BoFLC1-w/w and BoFLC5-w/w homozygous haplotype,and BoFLC3-w/z heterozygous haplotype(BC2F1-29)was obtained.The bolting time and flowering time of BC2F1-29 were 8.00 and 13.00 days later than those of backcross parent'20-2229',respectively.Four plants containing BoFLC1-w/w and BoFLC3-w/w homozygous haplotype,and BoFLC5-w/z heterozygous haplotype(BC2F1-55,BC2F1-119,BC2F1-121,BC2F1-163)were obtained.The average bolting time and flowering time of these four plants were 9.75 and 13.50 days later than those of'20-2229',respectively.In addition,three plants containing BoFLC1-w/w,BoFLC3-w/w and BoFLC5-w/w homozygous haplotype(BC2F1-82,BC2F1-106,BC2F1-192)were obtained.The average bolting time and flowering time of these three plants were 11.33 and 15.67 days later than those of'20-2229',respectively.In this study,BoFLCs specific molecular markers were developed and the excellent BoFLCs genotypes were efficiently pyramided and the bolting properties of parent'20-2229'was improved.
cabbageFLClate-boltingmarker developmentpyramiding of elite haplotypes