Callus induction, somatic embryogenesis and plant regeneration were ob
tained in two cultivars of Sorghum bicolor (L.) Moench. Transverse thi
n cell layers from roots/epicotyls of 15-day-old seedlings or of regen
erated plantlets were used. CaIlus response depended on the genotype,
the size of transverse thin cell layers, the level at which transverse
thin cell layers were excised on the epicotyl, the composition of gro
wth substances and the number of in vitro regeneration cycles undergon
e by the donor plant. Somatic embryos were differentiated under a defi
ned dark/light sequence, from epidermised compact calluses (i.e having
already differentiated an epidermis), obtained directly with dicamba
or from friable callus initiated with kinetin and 2,4 dichlorophenoxya
cetic acid. The importance of kinetin and dicamba on the induction of
embryogenic potential is reported.