Glucosinolates in seed of rape and turnip rape as affected by variety and environment

Seed meals of winter and summer types of varieties of Brassica napus and B. campestris, grown at different localities and in different years, have been analysed for content of glucosinolates which produce oxazolidinethiones and volatile isothiocyanates upon enzymic hydrolysis. Considerable differences existed in amounts of glucosinolates between species and between winter and summer types of the same species. Varietal differences were relatively small in most of the material studied. Samples of the Polish summer rape variety Bronowski and selections from this variety, however, exhibited very low glucosinolate contents; this is probably genetically determined. Environmental variation generally amounted to ±15% of the average value. Under certain environments, however, 65% lower values than average were obtained. Lack of sulphur in the growth medium of soil-free cultures resulted in seeds low in glucosinolates. In practical farming low glucosinolate content has been found in rape seed as a result of low sulphate content in the soil.