Authors:S. Stambouli, S. Bouzid, P. Dutuit, and Fethia Harzallah-Skhiri
The objective of this study was to vary the mineral composition of the culture medium of Prosopis farcta seedlings per addition of Na+ and Ca++ ions with the aim to identify the culture media which support the growth and/or the expression of the in vitro plant organogenesis. The Na+ and Ca++ ions were added in the culture medium in various concentrations by taking the Gamborg medium, in which macroelements were diluted 10 times, as the basic one. After two months of culture, parameters relating to the vegetative development of plant seedlings and to the various expressions of organogenesis were measured. Weak concentrations in sodium and calcium ions as well as a weak concentration in Ca++ (0.1 mM) with 50 mM in Na+ support the best vegetative development of the plantlets. The most important percentage of plant seedlings presenting a bud initiation was obtained on a medium containing 0.1 mM of Na+ and 50 mM of Ca++. Our study defined several media likely to support in vitro development of Prosopis farcta plantlets allowing the selection of salt tolerant plants or cellular lines. Some other media were chosen for improving micropropagation of the species without adding growth substances.
Authors:I. Saoud, L. Hamrouni, S. Gargouri, I. Amri, M. Hanana, T. Fezzani, S. Bouzid, and B. Jamoussi
The chemical composition, phytotoxic and antifungal activities of the essential oils isolated by hydrodistillation from the aerial parts of Tunisian thyme were evaluated. In order to find best results, different variables (i.e. provenance and phase of plant development) were considered. The chemical composition analysed by gas chromatography/mass spectrometry (GC/MS) revealed variability among provenances displaying interesting chemotypes and that carvacrol (63–84%), limonene (5–10%), δ-terpinene (0–7%), and β-myrcene (0–7%) were the main components. Antifungal ability of Thymus capitatus essential oils was tested by disc agar diffusion against five phytopathogenic fungi: Fusarium avenaceum, F. culmorum, Microdochium nivale var. nivale, Alternaria sp., and Bipolaris sorokiniana. High antifungal activity was observed for the essential oil isolated at the post-flowering development phase for the Bekalta provenance. There was no difference in the antifungal activities of oils isolated at the flowering phase from the other provenances. Thyme essential oils showed high level of weed-killer activity as well against Sinapis arvensis.