Effect of section of yam (Dioscorea cayenensis) tuber used in minisett on the biochemical properties of the resultant tuber

The effect of the section of yam (Dioscorea cayenensis) tuber used as planting material in minisett on the biochemical properties of the resultant tuber was studied. The biochemical parameters invertase (EC 3.2.1.26), acid phosphatase (EC 3.1.3.2), peroxidase (EC1.11.1.7), polyphenol oxidase (EC 1.10.3.1), total sugars and starch were evaluated in tubers resulting from field-grown and tissue culture-derived setts of the cultivars Roundleaf and Blackwiss yellow yams. No significant differences were observed between tubers resulting from field-grown and tissue culture-derived setts relative to the parameters studied. Invertase activity was found to be highest in tubers from middle-derived setts, while tail-derived setts had the lowest activity for both cultivars. Middle-derived tubers were also found to have significantly higher levels of acid phosphatase activity and starch content. However, middle-derived tubers had the lowest level of total sugars. Polyphenol oxidase and peroxidase were also found to be significantly higher in tubers from middle-derived setts. These results suggest a higher rate of active starch formation in tubers from middle-derived setts. © 2002 Society of Chemical Industry