Rape plants were labelled by applying (NH4)235SO4 to soil. Changes in content of 35S in various constituents in pods and grains were determined during siliquae development to exploit formation and accumulation of glucosinolates in oilseed rape. Content of 35S in glucosinolates expressed as μmol S/g.d.w. and its relative amounts in extractable forms in young siliquae were in constant level within one week after flowering, but either absolute content or relative content of 35S in glucosinolates increased largely by two weeks after flowering, thereafter the distribution of extractable 35S in glucosinolates of siliquae and grains increased linearly as proceeding of its development, 35S in extracts of grains almost was in form of glucosinolates after 8 weeks from flowering. Amounts of both 35S in glucosinolates and dry matter per pod increased linearly with time after flowering. According to the changes of amounts of 35S in other constituents per pod, it could be supposed that glucosinolates accumulated in seeds might be transported from other organs together with nutrients.

The conversion of SO2‐4 ‐S and changes in content of S in various constituents in leaves of rape seedlings transplanted were investigated by using (NH4)235SO4 as a tracer to exploit formation and accumulation of glucosinolates in oilseed rape. Seedlings grown under sandy culture absorbed 35SO2‐4 which was added to the cultural solution and incorporated into amino acids, glucosinolates and proteins rapidly. Distribution of extractable 35S with 70 % methanol in glucosinolates in leaves declined with time from labelling, while those in amino acids rised correspondingly. Per cents of 35S incorporated into bound form in total 35S increased linearly and those of 35S into glucosinolates and amino acids decreased with time within five days from labelling. After that the relative amounts of 3SS in three constituents was basically constant. Content on dry weight basis of labelled glucosinolates and amino acids expressed as μmol S/g.d.w. increased linearly with time from labelling with absorption of 35SO2‐4from soil by the seedlings under soil culture. Compared with seedlings grown under sandy culture, more 35S was incorporated into glucosinolates in leaves of seedlings grown under soil culture.