Introduction.Ximenia americana is a species developed in Africa
and South America. This fruit tree is threatened by a dangerous process of genetic
erosion. In vitro techniques could be used for its rapid clonal propagation.
Since there is still no report on vitroculture of the species, we tested its micropropagation
using axillary buds from mature plants of X. americana. Materials and methods.
Single node explants of X. americana shoots were cultured on a proliferation
medium made up with a MS medium containing different concentrations (2.5-15 μM)
of two cytokinins [benzyladenine (BA) or kinetin] used individually or in combination
with 0.5 μM of an auxin [2,4-dichlorophenoxyacetic acid (2,4-D) or naphtaleneacetic
acid (NAA)]. Data were recorded after 5 weeks of culture. From proliferated shoot clumps,
shoot explants (approximately 3 cm in length) were excised and transferred to rooting
media made up with MS medium with or without 0.5 M of indolebutyric acid (IBA) (pH = 5.8).
Results. The most rapid and earliest proliferation was observed in media with the
lowest concentrations of cytokinins. Absence of growth regulators in media and media
with 2,4-D or NAA considerably delayed bud proliferation. The number of shoots per
explant increased with the increase of cytokinins. The maximum number of shoots was
achieved in 10 μM BA. When shoots were transferred to rooting media, media supplemented
with 0.5 μM IBA improved the rooting frequency, root quality and number of roots per
cutting. After rooting, the vitroplants were transplanted into small polybags with
1:1 non-sterile soil and sand, then in the field after 4 weeks. Eighty percent of the plants
taken from regulator-supplemented media were acclimated versus 15% of those taken from
auxin-free media. Conclusion. The rapid clonal propagation of X. americana
is possible through in vitro culture of nodal explants. The best cytokinin for shoot
multiplication was BA.