Plant Breeding 123, 60—65 (2004) Ó 2004 Blackwell Verlag, Berlin ISSN 0179-9541 Genetic and environmental effects on glucosinolate content and chemoprotective potency of broccoli M. W. Farnham1 ,P.E.Wilson2 ,K.K.Stephenson3 and J.W. Fahey3,4 1 US Department of Agriculture, Agricultural Research Service, US Vegetable Laboratory, 2700 Savannah Hwy., Charleston, SC 29414, USA, E-mail:
[email protected]; 2 Phytochemicals and Health Group, New Zealand Institute for Crop and Food Research Limited, Private Bag 4704, Christchurch, New Zealand; 3 Lewis B. and DorothyCullman Cancer Chemoprotection Center, Department of Pharmacologyand Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; 4 Center for Human Nutrition, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA With 1 figure and 3 tables Received February 28, 2003/Accepted July 11, 2003 Communicated by G. Wricke Abstract gut as a result of the activityof its microflora (Shapiro et al. Broccoli is well recognized as a source of glucosinolates and their 1998, 2001). Certain isothiocyanates are known to inhibit isothiocyanate breakdown products. Glucoraphanin is one of the most tumour formation in mammals initiated bya varietyof abundant glucosinolates present in broccoli and its cognate isothio- chemical carcinogens (Zhang and Talalay1994). Sulphora- cyanate is sulphoraphane, a potent inducer of mammalian detoxica- phane, the cognate isothiocyanate of glucoraphanin (4-meth- tion (phase 2) enzyme activity and anti-cancer agent. This study was ylsulphinylbutyl glucosinolate), has been the focus of designed to measure: glucosinolate levels in broccoli florets from an numerous studies because it is a potent inducer of mammalian arrayof genotypes grown in several environments; the elevation of a detoxication and antioxidant (phase 2) enzyme activity that keyphase 2 enzyme,quinone reductase, in mammalian cells exposed to protects against tumourigenesis in a rodent mammarytumour floret extracts; and total broccoli head content.