Chemical composition and antifungal activity of the essential oils of three species of Artemisia on some soil-borne phytopathogens.

Various species of the genus Artemisia are used for their pharmacological, antimicrobial, antioxidant activity. Three species of this genus, Artemisia scoparia, A. sieberi and A. aucheri are widely distributed in desert area of Iran. In order to identify the chemical composition, aerial parts of A. scoparia, A. sieberi and A. aucheri were collected from Bajestan (Khorasan province) at flowering stage. The essential oils were obtained by hydro-distillation of air-dried samples and their chemical composition identified by GC-MS. Oxygenated monoterpens were the major components of the oils of three species. alpha-thujone (81.7%), beta-thujone (14.5%) and 1,8-cineol (1.9%) were the major compounds in the essential oil of A. scoparia. The essential oil of A. aucheri was rich in linalool (44.1%), gernyl acetate (10.7%), (E)-citral (9.7%) and (Z)-citral (7.7%), and the essential oil of A. sieberi was rich in beta-thujone (19.8%), alpha-thujone (10.5%), camphor (19.5%), verbenol (9.7%), p-mentha-1,5-dien-8-ol (6.4) and davanone (5.8%). The essential oils of the three species were tested for their antifungal activity against some soil-borne pathogenic fungi. Results of bioassay showed that the oils of A. aucheri and A. sieberi has stronger antifungal activity. Minimum EC50 (41.406 microL/L), resulted from A. aucheri on Rhizoctonia solani. The oil of A. sieberi showed fungistatic activity against, Tiarosporella phaseolina (MIC = 1000 microL/L, EC50 = 203.419 microL/L), Fusarium moniliforme (MIC=750 microL/L, EC50 = 211.072 microL/L), Fusarium solani (MIC = 750 microL/L, EC50 = 188.134 microL/L) whereas against R. solani (MIC = 250 microL/L, EC50 = 121.798 microL/L) exhibited high fungicidal activity.