Extraction and qualitative and quantitative analysis of the essential oil of Thymus species cultivated in Yazd

The essential oil of Thymus spp has valuable components such as thymol and carvacrol. The aerial parts of different thymus accessions، cultivated in Shahedied research station of medicinal plants، were collected at flowering stage and then dried in shadow and hydro-distilled for obtaining their essential oils. Analysis and identification of chemical composition of the oil were performed by GC and GC/MS. Among 74 cultivated accessions in 2011، the highest amount of oil yield was related to the accessions CFTNJI (4. 17%)، ZELP (4%)، Q (3. 72%)، NJICFT (3. 71%)، XDRMKO (3. 54%)، respectively and the lowest was related to BHUZSE (0. 66%). The highest amount of oil production per hectare was related to the accesstions XDRVGY (87. 5kg/ha)، NJICFT (45. 42kg/ha)، ZSECFT (40. 86kg/ha)، BHUMKO (38. 31kg/ha)، respectively and the lowest was related to CFTMKO (0. 9kg/ha). Para-cymene، 1،8-cineol، gamma terpinene، borneol، thymol، carvacrol، geraniol، limonene، acetate geranil، terpineol، linalool، caryophyllene، respectively with values of 28. 41%، 31. 66%، 20. 44%، 29. 35%، 71. 1%، 81. 45%، 76. 99%، 43%، 28%، 38. 6%، 55. 56%، 81%، 20%، were related to the accessions VGYCFT، NJIBHU، MKOMKO، CFTCFT، ZSEQ، NJICFT، CFTQ، MKOQ، CFTZSE، NJIBHU، ZSEQ، NJICFT، CFTQ، MKOQ، CFTZSE، NJIBHU، ZSELP، VGYMKO. In (2012)، the highest amount of oil yield was recorded for the accessions Q (4. 07%)، CFTVGY (3. 7%)، MKOVGY (3. 63%)، ZSEQ (3. 45%)، ZSELP (%3. 43)، respectively and the lowest was found in VGYMKO (62. 0%). The highest amount of oil production per hectare was related to the accessions BHUVGY (74. 9kg/ha)، XDRVGY (60. 9kg/ha)، XDRLP (51. 78kg/ha)، CFT (49. 21kg/ha)، Q (46. 11kg/ha)، respectively and the lowest was found in BHUZSE (2. 36kg/ha). Generally، in terms of oil yield، oil production and main composition of essential oil، three accessions including NJICFT (Thymus Transcaspicus) with 3. 71% essential oil and 45. 42kg per hectare oil production and 81. 5 % carvacrol، ZSEQ (T. daenensis) with 3. 45% essential oil and 37. 15 kg/h oil production and 73% thymol، and XDRVGY (T. vulgaris) with 2. 75% essential oil and 78. 5kg/h oil production and 45. 8% thymol were selected as superior accessions.