3.2.2. Leaf segments
Different morphogenic responses were observed from leaf segments
according to type of growth regulator, explant orientation
and incubation condition. Plant production via direct organogenesis
was observed after 30 days culture from the wound surfaces
and midvein of explants cultured in the presence of light with the
adaxial surface in contact with the medium (MSM supplemented
with 13.2 and 22 M BA) (Fig. 1e), at frequencies of 20 and 33%,
respectively, with a mean production of 2 shoots/explant. After
60 days culture, compact, green, non-morphogenic calluses were
also observed. However, when cultured with the abaxial surface
in contact with the medium leaf segments showed the formation
of non-morphogenic compact calluses, with friable regions
at the surface, in response to all BA concentrations (Fig. 1f). Nonmorphogenic
compact calluses were also observed from cultures
maintained in the dark, irrespective of explant orientation.