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Yeast extract (YE) is an elicitor which can enhance secondary metabolite contents in many medicinal plants. Therefore, the objective of this study was to investigate effect of YE elicitation period on total saponin content, total phenolic content and DPPH radical scavenging activity of Dioscorea birmanica Prain & Burkill shoot under aseptic conditions. Node explants were cultured on MS medium supplemented with or without 3 g/L YE for 1, 2, 4 and 6 weeks. The experiment was arranged in 2 x 4 factorial in Completely Randomized Design (CRD). The results revealed that there was an interaction between YE supplementation and elicitation period on total saponin content. The highest total saponin content of 1,233.33±47.15 µg diosgenin/g dry extract or 1.93 times of non YE shoots was achieved when the shoots were grown on MS medium supplemented with 3 g/L YE for 2 weeks. However, YE had no effect on total phenolic content and DPPH radical scavenging activity.
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