Capturing the Brassica oleracea L. wild relatives diversity for improving nutraceutical traits of cole crops

Crop Wild Relatives (CWRs) belonging to the Brassica oleracea L. gene pool represent a valuable reservoir of genetic diversity. These species are characterized by their resilience and serve as a rich source of alleles for stress resistance, as well as for desirable nutritional traits that can be readily transferred to cultivars through breeding programs. This study investigated the morphological diversity and biochemical profiles of seven Brassica CWRs: B. macrocarpa Guss., B. villosa Biv., B. rupestris Raf., B. incana Ten., B. drepanensis (Caruel) Dam., B. insularis Moris, and B. montana Pourr. Morphometric analysis identified the main phenotypic traits, accompanied by glucosinolate quantification to assess biochemical variability. Principal Component Analysis (PCA) revealed a clear distinction between BY2 (B. incana) and BX1 (B. montana), which significantly differed from the other genotypes in both morphological and biochemical profiles. These accessions exhibited high glucosinolate concentrations, confirming their unique metabolic composition compared to the other accessions analyzed. The glucosinolate profile showed substantial variability across accessions, with total glucosinolates concentrations ranging from 26.55 mu mol g-1 d.w. in BV1 to 223.86 mu mol g-1 d.w. in BX1. Sinigrin (SIN) reached the highest concentration (92.86 mu mol g-1 d.w.) in B. macrocarpa (BM3), while BY2 showed the highest levels of sinalbin (SIB), glucoerucin (GER), and glucobrassicin (GBS). Correlation analysis revealed strong associations, particularly between SIB and GER, GBS and GER. Overall, the results highlight the high morphological and biochemical variability among the analyzed accessions, reaffirming the value of Brassica CWRs as a critical source of genetic diversity for crop improvement.