A simple and efficient protocol is described for regeneration of wild sorgh
um (Sorghum dimidiatum) from cell suspension cultures. Fast-growing cell su
spensions were established from shoot-meristem-derived callus. Plating of t
he suspension on Murashige and Skoog agar medium supplemented with 2.5 mg 1
(-1) 2,4-dichlorophenoxyacetic acid (2,4-D) resulted in the formation of em
bryogenic calli. High-frequency (80%) somatic embryogenesis from small cell
clusters (300-400 mu m) was observed when the cultures were initially main
tained in liquid medium with reduced levels of 2.4-D (0.25 mg 1(-1)), follo
wed by transfer to regeneration medium. Direct plating of these small clust
ers on regeneration medium or transfer to liquid regeneration medium contai
ning kinetin and 6-benzylaminopurine resulted in the development of mature
somatic embryos and plantlets. The regenerants developed to maturity and we
re all phenotypically and cytologically normal.