The Effect of Sulfur Fertilizer on Glucoraphanin Levels in Broccoli (B. oleracea L. var. italica) at Different Growth Stages

• Published in: Journal of agricultural and food chemistry 2004-05, Vol.52 (9), p.2632-2639
• Main Authors: Rangkadilok, Nuchanart, Nicolas, Marc E, Bennett, Richard N, Eagling, David R, Premier, Robert R, Taylor, Paul W. J
• Format: Article
• Language: English
• Subjects: application rate; application timing; Biological and medical sciences; Brassica - chemistry; Brassica - growth & development; Brassica oleracea var. italica; broccoli; Calcium Sulfate; chemical constituents of plants; cultivars; curds (plant); developmental stages; fertilizer application; Fertilizers; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Glucose - analogs & derivatives; Glucose - analysis; Glucosinolates; gypsum; Imidoesters - analysis; nutrient content; nutrient uptake; seeds; Seeds - chemistry; Sulfur; sulfur fertilizers
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf030655u

Three sulfur (S) treatements were imposed by applying gypsum to three broccoli cultivars (Claudia, Marathon, and TB-234) known to differ in glucoraphanin content of mature seeds. The S treatments were control (very low added S), low S (23 kg S ha-1), and high S (92 kg S ha-1). The gypsum applications during the early vegetative phase of the three broccoli cultivars increased S uptake and the glucoraphanin content in each plant organ. There were significant genotypic differences for the content of both S and glucoraphanin in all plant organs at different growth stages with gypsum applications. A large increase in S and glucoraphanin content was found in the green heads of broccoli and mature seeds. S present in glucoraphanin accounted for only 4−10% of total S content in broccoli heads. However, S present in glucoraphanin in mature seeds accounted for 40−46% of the total S in the seeds of moderate and high glucoraphanin cultivars (Marathon and TB-234). The partitioning of S into glucoraphanin also increased with gypsum applications. Differences in S uptake, S distribution between organs, and partitioning of S into glucoraphanin largely explained the differences in glucoraphanin content in the green heads and mature seeds for the three broccoli cultivars and three S treatments. Keywords: Glucoraphanin; broccoli; gypsum; sulfur