Identification of a major QTL for seed number per silique in cabbage (Brassica oleracea L. var. capitata) using genotyping by sequencing

Seed number per silique is a major factor that affects cabbage seed yield. To identify quantitative trait loci (QTL) related to seed number per silique and develop linked markers for cabbage molecular marker-assisted breeding, a double haploid (DH) population with 100 individuals, derived from two founder parents (01-20 and 96-100) with notable differences in seed number per silique, was subjected to whole-genome resequencing. Genotyping by sequencing (GBS) technology was applied to construct a high-density SNP-based genetic linkage group with 1465 bin markers, covering 1285.77 cM of genome length, with an average genetic distance of 0.88 cM between adjacent bin markers. Finally, one significant QTL, qSNS6.1, on chromosome 6 was repeatedly detected in two experimental years, with a mean contribute rate of 15.2% and LOD value of 3.1. The major QTL qSNS6.1 will facilitate further understanding of the genetic basis of seed number per silique, and the development of genetic markers linked with seed number per silique would save time and reduce labor intensity by allowing selection of this trait at the seeding stage of cabbage.