Abstract

The embryogenic ability of two cassava cultivars (Sandpaper and TMS 60444) was investigated by culturing their young leaf lobes on an induction medium (DKW2 50P). The explants formed organized embryogenic structures regardless of the concentration of picloram in the medium. Organized embryogenic structures induction was enhanced by increasing the concentration of picloram in the induction medium for both cultivars. The optimum level of picloram at which maximum stable frequencies (53.1±17.6 and 51.5±14.6 for Sandpaper and TMS 60444 respectively) of organized embryogenic structures were obtained was 5 mg/l. Friable embryogenic callus were further produced in GD2 50P medium supplemented with 500 µM tyrosine. The produced friable embryogenic calluses are prime target tissues for genetic transformation and plantlet regeneration.

Key words: Cassava cultivars, explants, organized embryogenic structures, friable embryogenic callus, picloram, tyrosine.