In the course of the subculture of callus,the gutta content increased along with the increase of subculture in number of times,with a peak in the 4 to 7 times and a sharp decline after 8 times.Although illumination increased the gutta content,the propagation times of callus decreased;therefore the total production efficiency of gutta was high under dark culture.The gutta content and productivity in the static solid culture were higher than those in te liquid shaking culture.A better production procedure of ...