Development of friable embryogenic callus and embryogenic suspension culture systems in cassava (Manihot esculenta Crantz).

Procedures for the production of a new and highly prolific embryogenic culture system have been developed in cassava. The importance of the basal salts and type of auxin in controlling the development of cassava embryogenic tissues has been demonstrated, with culture on Gresshoff and Doy basal medium in the presence of 4-amino-3,5,6,trichloro-picolinic acid (picloram) inducing the formation of friable embryogenic callus from which highly totipotent embryogenic suspension cultures could be established. Plants have been regenerated from these cultures. The availability of embryogenic suspension cultures is considered to have important implications for the application of genetic transformation and other biotechnologies in the agronomic improvement of cassava.