Lipid peroxidation, o-diphenolase, superoxide dismutase and catalase profile along the three physiological regions of Dioscorea rotundata Poir cv Omi

The head region of Dioscorea rotundata Poir CV Omi is bitter in taste when eaten but is the most productive region for propagation when compared to the other two physiological regions; middle and tail. In this study some biochemical parameters are highlighted to explain these two differences. o-Diphenolase activity was highest in the head region, followed by the tail region and lastly the middle region while the level of lipid peroxidation was highest in the middle region, followed by the tail and lastly the head region. The activities of superoxide dismutase and catalase exhibited a similar pattern of distribution with the highest activities recorded in the tail region and followed by the head region. The middle region had the least antioxidant enzyme activities. (C) 2000 Elsevier Science Ltd. All rights reserved.