Biological control of plant diseases makes extensive use of the antagonists. The effectiveness of the control depends on the choice of an effective antagonist strains from criteria of implying a good knowledge of biological peculiarities of the material used. In this study, the antagonistic activities of nine isolates of Bacillus amyloliquefaciens and one isolate of Trichoderma harzianum were tested in vitro against seven strains of Colletotrichum acutatum, the causal agent of strawberry anthracnose. It was found that T. harzianum and B. amyloliquefaciens strains showed the ability to inhibit the mycelial growth of the pathogen by dual culture technique by more than 50 percent. The nonvolatile substances produced by the antagonists showed high inhibition percentages that are more than 99 percent, meanwhile their volatile compounds inhibited the mycelial growth of C. acutatum strains with low inhibition percentages starting from 30 percent except the substances produced by B. amyloliquefaciens Bc2 that showed a high inhibition percentage of more than 70 percent.

The increasingly strict regulation of the use of phytosanitary products and the will of the populations to move towards sustainable development allow bio-sourced products and more particularly for biocontrol in the field of pesticides to progress. The study carried out here concerns the evaluation of the potency of Bacillus amyloliquefaciens Bc2 and Trichoderma harzianum to fight against strawberry cultures infected with anthracnose (Fragaria × ananassa Duch.). The studies were carried out in the laboratory and in the field. The results indicate that B. amyloliquefaciens Bc2 and Trichoderma harzianum TR are effective for the biological control of anthracnose, gray mold and powdery mildew on strawberries grown in field conditions. The increase in plant size and the number of fruits produced with these control agents has also been observed.

Micropropagation from shoot tips and nodal segments was carried out for the conservation and domestication of spontaneous Moroccan thyme, Thymus broussonetii Boiss. subsp. broussonetii (endemic threatened). The mineral composition of the culture medium, as well as the succession of different growth regulators, influenced the in vitro growth of this species. Sterilized achenes of T. broussonetii were able to germinate on an agar medium containing Gautheret macronutrients with a rate of 25% and a degree of contamination of less than 4%. Shoot apices of 15-day seedlings (two cotyledon leaves) were cultivated on SD + 0.46 μM Kin medium and the explants obtained were transplanted every month. Six macronutrients (MS, B 5 , SH, SD, MS m and N 30 K) were tested and N 30 K was chosen for the following experiments. Seven cytokinins (Kin, BAP, 2iP, DPU, adenine, Zeat and TDZ) at 0.46, 0.93 and 2.32 µM/l were evaluated and the addition of 0.93 µM adenine to N 30 K medium favored significantly the induction of buds and the elongation of explants. Three polyamines (putrescine, spermidine and spermine) at 2, 5, 10 and 20 µM/l were tested. A better multiplication of buds, shoots and roots was noted for N 30 K + 10 µM spermine. Cytokinin-auxin combinations led to better root multiplication and an increase in the number of buds and the length of explants, particularly for 0.46 µM Kin + 2.85 µM IAA. Acclimatization was successfully carried out using vitroplants developing a good root system.

The present study reports an efficient protocol for in vitro propagation of Thymus vulgaris L., an aromatic and medicinal plant in Morocco. Initially, we performed in vitro multiplication of Thymus vulgaris explants existing in the laboratory and obtained from micropropagation by shoot tip culture. Afterwards, we have evaluated the effect of six macronutrients. After that, seven cytokinins (Kin, BAP, 2iP, DPU, Adenine, Zeatine and TDZ) in three different concentrations (0.46, 0.93, 2.32 µM) have been evaluated to optimize cultures multiplication and elongation. Moreover, the effect of three auxins (IAA, IBA and NAA) at 0.57 µM, combined to 4 cytokinins (Kin, BAP, DPU and Ad.) at 0.46 μM, on shoot rooting has been studied. Thereby, MS medium has been proved the most favorable for plantlets growing. Also, we found that the addition of certain cytokinins, specifically 0.46 Kin, 0.46 and 0.93 BAP, 0.46 2iP, 0.46 DPU, 0.46 Ad. and 0.46 Zeat., ensures better multiplication and growth of vitroplants. In addition, multiplication and rooting of cultures were well optimized after addition 0.46 Kin + 0.57 IAA or NAA, 0.46 DPU + 0.57 IBA and 0.46 Ad. + 0.57 IBA combinations to the culture medium. Lastly, plantlets with roots were successfully acclimatized to ex-vitro conditions and these latter served as a source to establish in vitro culture again.

The effect of nine isolates of Bacillus amyloliquefaciens and one strain of Trichoderma harzianum, TR, on mycelial growth and germination of Colletotrichum acutatum were studied. The nine isolates were identified as Bacillus amyloliquefaciens. The efficacy of isolates was tested, at different concentrations. Results showed that one Bacillus isolates (Bc2) and TR were more effective at the lower concentration tested (3 × 10 5 CFU/ml and 10 5 conidia/ml).