Identification of glucosinolate-associated QTLs in cabbage (Brassica oleracea L. var. capitata)

Glucosinolates are one of the important plant secondary metabolites that are produced mainly in Brassicaceae plants. The compounds are primarily involved in defense responses to biotic and abiotic resistance in plants and play important biological roles during plant growth and development. In this study, the glucosinolate profiles in leaves of two different Brassica oleracea populations were compared using high-performance liquid chromatography (HPLC). The nine major glucosinolates compounds in cabbage leaves were identified as belonging to the aliphatic and indolic groups. Among them, sinigrin, which belongs to the aliphatic group, was recorded to be 41% whereas glucobrassicin and 4-methoxyglucobrassicin, which belong to the indolic group, were recorded to be 53.8%. In addition, we performed a genetic analysis to identify regions of the genome regulating glucosinolates biosynthesis in the $F_3$ population of Brassica oleracea. A total of 9 glucosinolates were used for the quantitative trait locus (QTL) analysis. Out of 9, a total of 3 QTLs were identified and they were associated with sinigrin, glucobrassicin, and 4-methoxyglucobrassicin synthesis located in Chromosome 1 and Chromosome 8, respectively. The results of this study will provide valuable information for the breeding of cabbage containing high glucosinolate content, and our next target is to develop component-specific and tightly linked markers for various glucosinolates.