Lippia citriodora H.B.K. is an aromatic plant indigenous to South America. It is cultivated and commercialised as an ornamental for its lemon-like scent emitted from its leaves and flowers. The present morphoanatomical and histochemical study revealed that leaves of L. citriodora possess one type of setae (non-glandular) and at least five types of glandular trichomes, with the latter differing anatomically and in the composition of their secondary metabolites. Scanning electron microscopy revealed that the same types of trichomes exist also on the calyces. Histochemical tests indicate that the glandular trichomes contain a combination of terpenoids, flavonoids, carbohydrates, phenolics and alkaloids. However, within the vacuoles of the mesophyll cells, terpenoids, phenolics, flavonoids and tannins are stored. The presence of lamellar cytoplasmic inclusions in the mesophyll cells, possibly precursors of tannins stored in the vacuoles, is reported for the first time.

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The demand for aromatic plants as ornamentals and sources of essential oils has increased recently. A float system is a promising alternative method of seedling production. Two cropping systems, float and conventional (seed bed), and two nutrient solution formulations, one organic and one inorganic, were evaluated for Ocimum basilicum (basil) and Mentha spicata (spearmint) seedling production. Basil seedlings grown in float system had better or comparable growth of shoots and leaves with those grown in seedbeds, irrespective of the fertilization, whereas spearmint organic fertilization reduced the growth of the aboveground parts of the seedlings, regardless of the cropping system. By contrast, fertilization treatments on both species’ seedling grown in float system showed better root length and higher root biomass accumulation. The survival percentage of seedlings after transplanting, as well as the subsequent growth of plants, were not seriously affected by the cropping system of the fertilization method during transplant production. Overall, we conclude that a float system can be used for the production of Ocimum basilicum and Mentha spicata seedlings under organic or inorganic fertilization.

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Hypericum empetrifolium Willd. subsp. empetrifolium is an evergreen small shrub with small elongated decorative leaves and small yellow flowers in inflorescences, characterized for several pharmaceutical properties. In the present study, a first approach on the sexual and asexual propagation of this species was performed. Seeds, subjected to different types of pre-treatments [soaked in tap water; 50, 100 or 150 mg L-1 GA3 for 30 min and no treatment (control)], cultured for germination in petri dishes at 5, 10, 15, 20, 25, and 30 °C. Seed germination was only affected by temperature and the best result was obtained at 15 °C (71.2%). A significant interaction was found between pre-treatments and incubation temperature with the highest germination percentage (82%) occurred when the seeds soaked in 100 mg L-1 GA3 solution for 30 min and incubated at 20 °C constant temperature. Moreover, the germination speed was fastest from 20 to 25 °C (T50= 9.84 and 9.56 days for 20 and 25 °C, respectively). For asexual propagation, apical stem cuttings were taken at four different periods (4 seasons) and treated with IBA at concentrations of 0, 1000, 2000 and 3000 mg L-1. The cuttings were planted in a peat/perlite mixture 1:1 v/v in plastic square plug trays in order to study the rooting percentage. Winter was the most appropriate season for cuttings collection (100% rooting percentage) and dipping in 1000 or 2000 mg L-1 IBA (72% and 73%, respectively) was the best rooting hormone treatment.