Alkaloids of diferent plant, including many Solanaceae species, constitute important natural sources for variety of pharmaceutical products. The amounts of various secondary plant products are strongly dependent on the growing conditions and agronomical applications such as planting date, fertilization, irrigation etc. The aim of this was to study the effects of sowing date on some agronomic characteristics and total alkaloid content of thorn apple (Datura stramonium), investigated in the environmental conditions from Dicle University, Agricultural Faculty, Field Crops Department experimental area, during 2010 and 2011 growing years. In the research, plant height, stem diameter, number of branches per plant, number of capsule per plant, capsule width, capsule length, 1000-seed weight, fresh herb yield, herba yield, seed yield and total alkaloid content were examined. At the end of the study, in the trial of thorn apple with sowing dates, according to two years mean, seed yield, fresh herb yield, dry herb yield and total alkaloid yield were changed between 335 kg ha−1 and 704 kg ha−1, 5933 and 20537 kg ha−1, 1613 kg ha−1 and 4800 kg ha−1, and 0.270% and 0.391%, respectively. The effect of sowing date was found significant on the investigated characteristics, when sowing delayed, agronomic characteristics were also decreased. The highest values related with seed yield, fresh and dry herbage of thorn apple were obtained sowing of 01 Apr. Moreover, thorn apple plant showed morphogenetic variation when compared leaf and seed alkaloid contents.
Lemon verbena (Lippia citriodora H.B.K., Verbenaceae family) is indigenous to South America and cultivated as an aromatic plant in various parts of world. Lemon thyme (Thymus citriodorus L.), Lamiaceae family, is a perennial medicinal plant native to southern Europe and is cultivated in the Mediterranean region. These species are cultivated mainly for the lemon-like aroma emitted from their leaves due to the presence of dimethyl-2,6- octadienal, also known as lemonal or citral, which is used in food and perfumery for its citrus effect. The aim of this study was to determine the mineral content and essential oil components of L. citriodora and T. citriodorus plants grown under semi-arid climatic conditions in Turkey. The aerial parts of lemon thyme and lemon verbena plants were extracted using hydrodistillation. The essential oil composition was analyzed by gas chromatography-mass spectrometry (GC-MS) and the microelement contents of the herbs were examined via inductively coupled plasmaoptical emission spectrometry (ICP-OES). The microelement contents were 0.249, 1.630, 16.41, 0.106, and 13.1-36.2 mg kg-1 for cadmium (Cd), copper (Cu), iron (Fe), and manganese (Mn), respectively, in lemon thyme, and 0.275, 4.584, 248.1, 15.71, and 1.803 mg kg-1 for Cd, Cu, Fe, Mn, and zinc (Zn), respectively, in lemon verbena. Fifty compounds were identified in lemon verbena essential oil, including limonene (30.33%), trans-citral (17%), cis-citral (12.77%), caryophyllene oxide (5.71%), and geraniol acetate (4.02%) that together constituted 99.86% of the oil composition. We also identified 22 compounds constituting approximately 85.11% of lemon thyme essential oil, including transgeraniol (30.07%), trans-citral (15.06%), cis-citral (11.71%), cis-geraniol (7.65%), and 3-octanol (6.18%).
Alkaloids, nitrogen containing basic substance, have a complex structure. They are one of the most important groups of secondary metabolites, which is synthesized in roots and transported to other organs. Since alkaloids are nitrogenous compounds, the availability of nitrogen is expected to play an important role in the biosynthesis and accumulation of alkaloids in plants. Nitrogen affects yield and quality of medicinal plants, therefore, growers usually apply large amount of nitrogen to obtain high yields. The objective of the present study was to determine yield, yield components and alkaloid content of two henbane species (Hyoscyamus reticulatus L. and Hyoscyamus niger L.), collected from wild flora of South-eastern Anatolia, grown under four nitrogen applications (0, 50, 100 and 200 kg ha−1), in 2010-2011 growing seasons. In the field trial, plant height, stem diameter, number of branches per plant, number of capsule per plant, capsule width, capsule length, number of seed per capsule, 1000 seed weight, seed yield per plant and total alkaloid content were investigated. The results of study showed that nitrogen doses were found important for investigated characters but not important for Hyoscyamus species. Seed yield per plant varied from 8.4 to 11.6 g per plant, their alkaloid contents were found between 0.14% and 0.21%.