Biosynthesis of ascorbic acid in germinating rapeseed cultivars.

Biosynthesis of ascorbic acid in irradiated and unirradiated germinating rapeseed cultivars was studied at ambient room temperature (20-35 degrees C). Appreciable quantities of ascorbic acid (19.8-24.1 mg/100 g) were detected in the seeds and synthesis of this vitamin increased significantly (three fold) with increasing germination time depending upon rapeseed cultivars (p < 0.05). Soaking of seeds in tap water (1:2) for 24 hours resulted in the decrease of the vitamin in each case. Among the radiation treatments (0.05-0.20 kGy), maximum amounts of ascorbic acid were found in 0.10 kGy (342.1 mg/100 g dry weight) and 0.15 kGy (113.8 mg/100 g wet weight) samples after 96 hours of germination. An overall significant linear relation (r = 0.96) was observed between vitamin biosynthesis and germination time upto 96 hours in rapeseed.