Optimisation of
the in vitro Regeneration and Callogenesis of Eucalyptus sideroxylon, a Natural
Resource of Eucalyptol
Chograni H., Lotfi M., Othmani S., Ben-Rejeb F. and Riahi L.
Res. J. Biotech.; Vol. 20(8); 17-24;
doi: https://doi.org/10.25303/208rjbt017024; (2025)
Abstract
The use of biotechnological techniques for the large-scale production of plant secondary
metabolites is increasingly recognized as a promising alternative, especially in
light of the ongoing climatic changes that are significantly reducing the arable
lands. Eucalyptus sideroxylon, is a medicinal, industrial and ornamental tree species
with significant economic and ecological potentials. The foliage of this species
provides a natural bioresource for the production of essential oils with Eucalyptol
content exceeding 85%. In this study the in vitro regeneration and callogenesis
of this species were assessed based on various experimental conditions. The initiation
of axenic in vitro cultures revealed a 100% response on Murashige and Skoog culture
medium phytohormone-free. The meta-topoline riboside (mTR) concentration 2.5 μM
engendered the best multiplication result with a response of 100%, the highest number
of microshoots per explant (9.17) and microshoots length (0.90 cm).
The effect of indole-3-butyric acid (IBA) on rhizogenesis after 4 weeks of in vitro
culture revealed that the concentration 5 μM resulted in the highest rooting response
(95%), the highest roots number (6.33) and the highest roots length (1.95 cm). The
initiation of callus from leaves, stems and roots resulted in a 100% response with
both applied phytohormones, 2,4-D and Picloram, at concentrations of 5 μM and 10
μM. A variation in the colour (green, red-pink, yellow) and texture (compact, friable)
of the induced calli was observed according to the applied experimental conditions.
Further investigations are required to improve the in vitro regeneration protocols
for this species, thereby enhancing the sustainable biotechnological production
of high-value secondary metabolites.
