L. Safaei; E Sharifi Ashoorabadi; H. Zeinali; D. Afiuni; M. Mirza
Abstract
In order to study the effects of harvesting stages on essential oil yield and composition of Thymus caramanicus Jalas, an experiment was conducted during 2007-2009 in Fozveh Research Station of Isfahan. collected seeds from natural habitat were cultivated in pots and then seedlings were transplanted ...
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In order to study the effects of harvesting stages on essential oil yield and composition of Thymus caramanicus Jalas, an experiment was conducted during 2007-2009 in Fozveh Research Station of Isfahan. collected seeds from natural habitat were cultivated in pots and then seedlings were transplanted at the main field in a randomized complete blocks design with 3 replications. Aerial parts of the species were harvested at 4 stages including: beginning of flowering, fifty percent flowering, full flowering and fruit set during two years. The plant materials were dried and their essential oils were obtained by water distillation. Capillary GC and GC/MS analysis were used to determine the volatile profile of essential oil samples. Results showed that harvesting stages had significant effects on thymol and carvacrol content and essential oil percentage. The highest amount of essential oil and thymol percentage were obtained at full flowering stage of the first year (1.56% and 3.59 kg/ha, respectively) and the maximum carvacrol percentage was obtained at fruit set stage of the first year (25.45 kg/ha). Six components consisted the highest amount of essential oil, among them carvacrol was dominant at all 4 harvesting stages. The highest amount of carvacrol was obtained at the beginning of flowering stage (88.45%) in the second year. Thymol was the second dominant component with a maximum percentage of 11.77%, obtained at full flowering stage. The highest content of ρ- cymene, 1,8-cineole and γ-terpinene were obtained at fruit set stage (2.35, 1.21 and 2.15%, respectively) and the highest content of borneol was recorded at full flowering stage (7.52%). Also, a positive correlation was observed between essential oil percentage and amounts of thymol and carvacrol. In conclusion, the best time for harvesting of T. caramanicus to achieve the maximum carvacrol percentage was fruit set stage, while full flowering stage was identified as the best time to achieve the maximum essential oil and thymol percentage.
M. Bigdeloo; V. Nazeri; J. Hadian
Abstract
Thymus caramanicus Jalas is belonging to family Lamiaceae. Among 250 species of this genus with a worldwide distribution, 14 species grow naturally in Iran. Thymus caramanicus Jalas is one of the endemic species which has distribution in central Iran. In this study, natural habitats of the species were ...
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Thymus caramanicus Jalas is belonging to family Lamiaceae. Among 250 species of this genus with a worldwide distribution, 14 species grow naturally in Iran. Thymus caramanicus Jalas is one of the endemic species which has distribution in central Iran. In this study, natural habitats of the species were identified in different regions of Kerman, Esfahan and Semnan provinces in 2010.Ten complete plants at flowering stage were collected from seven localities in order to study and evaluate the morphological characters. Flowering stems were used to extract essential oil. Characteristics associated with each habitat were recorded and three soil samples from each site were taken to evaluate soil physical and chemical properties. Vegetative and reproductive characteristics of each population and the essential oil of the studied species in each habitat were recorded. Results were analyzed using cluster analysis method with SPSS software and correlation between evaluated traits and essential oil productivity were determined. Populations were clustered in two groups based on all studied characters. Populations collected from Kerman and Esfahan provinces were located in a same group and populations from Semnan province were placed in an independent group. Differences between these two groups may be from different climates in their habitats and their adaptation to the different environmental factors. According to the results, the best vegetative and also reproductive characters such as flowering stem length, leaf length and width, number of flowers per inflorescence and corolla length and also the highest essential oil production (2-3%) were recorded for specimens from Kerman province; therefore, it is recommended for breeding programs or cultivation.
