Quantification and Diversity Analyses of Glucosinolates in 191 Broccoli Genotypes Highlight Valuable Genetic Resources for Molecular Breeding

Abstract

Glucosinolates (GSLs), crucial secondary metabolites in cruciferous vegetables, hydrolyze upon consumption or mechanical damage, forming bioactive compounds with anti-cancer properties, such as glucoraphanin (GRA). Among cruciferous vegetables, broccoli stands out for its high GSL content, which varies significantly among different genotypes. This study aimed to characterize and quantify glucosinolate compounds in broccoli using LC-HRMS2 and UPLC. We identified thirteen GSLs in 191 broccoli genotypes, including seven aliphatic, five indole, and one aromatic glucosinolate. The GSL content in these genotypes ranged from 0.1705 to 5.8174 mg/g (DW). We also explored GSL diversity and content in seven developmental organs, finding high diversity and content in seedling roots and florets. Notably, genotype No. 300 had the highest GSL content (5.8174 mg/g, DW) and GRA (3.1545 mg/g, DW), along with a larger flower bulb diameter (13.4 cm) and a shorter growth stage (11 days), demonstrating its potential for breeding GRA-rich broccoli. To our knowledge, this study encompasses the largest number of broccoli genotypes to date, broadening our understanding of GSLs’ diversity and content in broccoli. These findings may provide valuable resources for future breeding or the commercial cultivation of GRA-rich broccoli.