Benchmarking Bulb\nYield, Medicinal Sulfur Compounds,\nand Mineral Nutrition of Garlic Varieties

Garlic is widely cultivated for both its culinary and\nmedicinal\nproperties. Bulb yield, organosulfur compounds, and plant mineral\nnutrition of 32 garlic varieties were characterized. Across genotypes,\nthere was large variability in bulb weight and alliin and allicin\nconcentrations. The mineral concentration of a reference leaf was\nstrongly positively correlated with bulb weight (for Zn, N, and K)\nand bulb allicin concentration (for S, Mo, and Cu). Alliin represented\n∼61 and 88% of the total clove S content. <i>In situ</i> synchrotron-based X-ray absorption near-edge structure (XANES) analysis\nidentified two dominant S compounds, γ-l-glutamyl-<i>S</i>-allyl-l-cysteine and alliin. Stoichiometric studies\nshowed the ratio of conversion of alliin to pyruvate was consistently\nbelow the theoretical 1:1 ratio, while the ratio for conversion of\nalliin to allicin was consistently higher (∼1.9:1 to 3.5:1).\nA combination of optimized fertilizer management and genotype selection\nfor high alliin can potentially substantially increase the yield and\nmedicinal quality of garlic.