Identification of Candidate Genes for Clubroot-Resistance in Using Quantitative Trait Loci-Sequencing.

Clubroot caused by is a devastating disease of cabbage (). To identify quantitative trait loci (QTLs) for clubroot resistance (CR) in , genomic resequencing was carried out in two sets of extreme pools, group I and group II, which were constructed separately from 110 and 74 F2 cloned lines derived from the cross between clubroot-resistant (R) cabbage "GZ87" (against race 4) and susceptible (S) cabbage "263." Based on the QTL- (QTL-Seq) analysis of group I and group II, three QTLs (i.e., , and ) were determined on the C07 chromosome. RNA-Seq and qRT-PCR were conducted in the extreme pools of group II before and after inoculation, and two potential candidate genes (i.e., and ), which exhibiting upregulation after inoculation in the R pool but downregulation in the S pool, were identified from the three QTLs on C07. A functional marker "SWU-OA" was developed from on C07, exhibiting ∼95% accuracy in identifying CR in 56 F2 lines. Our study will provide valuable information on resistance genes against and may accelerate the breeding process of with CR.