Background: Belonging to the Boraginacae family, Ehretia asperula Zoll. et Mor., called “Xa den”, is a precious medicinal plant also known as the “cancer tree” by the Muong ethnic group in Hoa Binh Province, Vietnam. Xa den has been demonstrated to inhibit the development of malignant tumors, reduce oxidation and enhance the human immune system. This research focused on examining friable callus induction from young stems of Ehretia asperula Zoll. et Mor. Methods: Samples of Xa den were less than two years old. Young stems with 2 to 6 leaves served as explants for callus induction. Explants placed on autoclaved B5 nutrients incubated at 25oC, in the dark. The testing factors were concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) and Benzyl adenine (BA), types and concentrations of sugars.Result: Friable callus was induced on B5 medium with 0.4 mg/L of 2,4-D, 0.1 mg/L of BA and 30 g/L of glucose at the highest rate (100%). Additionally, callus grew best after 5 weeks of culture weighing 0.194 g. Friable callus was used as material for cell suspension cultures. After two weeks, the Xa den cell suspension cultures contained single cells and small cell clumps. The liquid medium had changed from dark yellow to light brown.
Effects of Plant Growth Regulators and Sugars on Ehretia asperula Zoll. et Mor. Cell Cultures