In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration (EC50) values (ppm) of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm). Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest EC50 values for inhibition of the mycelial growth of P. capsici (31.473), P. melonis (33.097) and P. drechsleri (69.112), respectively. The mean EC50 values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds β-geranial (α-citral) (39.16%) and z-citral (30.95%) were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control (p≤0.05). Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases.

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In the present study, multiplication efficiency of Alstroemeria ligtu hybrid was investigated. Bases of the first seedling leaves grown in vitro were used as initial explants. The explants were cultured in the MS media containing 3% sucrose, 0.7% agar at pH 5.8, five N6-benzylaminopurine (BAP) concentrations (0, 0.5, 1, 1.5 and 2 mg·1-1) and three indole-3-butyric acid (IBA) concentrations (0, 0.1 and 0.2 mg·1-1). The cultures were incubated at 21 ± 2 °C under photoperiod 16/8. After three subculturings (3 weeks-long each) the number of rhizome, shoots, buds, leaves, and roots, length of shoots and roots were recorded. Adventitious shoots formed directly on the leaf bases without callus intervention. Their number was affected by BAP concentrations. The highest shoots number, six per explants, was obtained at 1 mg·1-1 BAP and 0.1 mg·1-1 IBA. The shoot length decreased with the increasing concentration of BAP. The highest root number (2.7) was formed on shoots cultured on the MS medium containing 0.5 mg·1-1 α- naphthalene acetic acid, and the highest rhizome number (2.2) was formed on the medium with 0.5 mg·1-1 BAP. In vitro rooted plantlets were able to survive and acclimatize in the greenhouse.

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