title: Increase of Chamazulene and α-Bisabolol Contents of the Essential Oil of German Chamomile (Matricaria chamomilla L.) Using Salicylic Acid Treatments under Normal and Heat Stress Conditions.
abstract: The chamazulene and α-(-)-bisabolol contents and quality of the chamomile oil are affected by genetic background and environmental conditions. Salicylic acid (SA), as a signaling molecule, plays a significant role in the plant physiological processes. The aim of this study was to evaluate the chemical profile, quantity, and improve the essential oil quality as a consequence of the increase of chamazulene and α-(-)-bisabol using salicylic acid under normal and heat stress conditions by the gas chromatography-mass spectrometry (GC-MS) technique. The factorial experiments were carried out during the 2011-2012 hot season using a randomized complete block design with three replications. The factors include four salicylic acid concentrations (0 (control), 10, 25 and 100 mg·L-1), and three chamomile cultivars (Bushehr, Bona, Bodegold) were sown on two different planting dates under field conditions. Fourteen compounds were identified from the extracted oil of the samples treated with salicylic acid under normal and heat stress conditions. The major identified oil compositions from chamomile cultivars treated with salicylic acid were chamazulene, α-(-)-bisabolol, bisabolone oxide, β-farnesene, en-yn-dicycloether, and bisabolol oxide A and B. Analysis of variance showed that the simple effects (environmental conditions, cultivar and salicylic acid) and their interaction were significant on all identified compounds, but the environmental conditions had no significant effect on bisabolol oxide A. The greatest amount of chamazulene obtained was 6.66% at the concentration of 10 mg·L-1SA for the Bona cultivar under heat stress conditions, whereas the highest α-(-)-bisabolol amount attained was 3.41% at the concentration of 100 mg·L-1SA for the Bona cultivar under normal conditions. The results demonstrated that the application of exogenous salicylic acid increases the quantity and essential oil quality as a consequence of the increase of chamazulene and α-(-)-bisabolol under normal and heat stress conditions.
authors.affiliation: Department of Research and Development, Sea Bioprospecting Co., Ltd., Tangestan Growth and Technology Center, Persian Gulf Science and Technology Park, Bushehr 7515797414, Bushehr, Iran. m.ghasemi22@gmail.com.|Department of Plant Breeding, Faculty of Agriculture and Natural Resources, Persian Gulf University, Bushehr 7561158818, Bushehr, Iran. m.ghasemi22@gmail.com.|Young Researchers and Elite Club, Bushehr Branch, Islamic Azad University, Bushehr 751961955, Iran. m.ghasemi22@gmail.com.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Ghasemi
authors.affiliation: Department of Plant Breeding and Biotechnology, Faculty of Crop Science, Sari Agricultural Sciences and Natural Resources University, Sari 578, Mazandaran, Iran. n.babaeian@sanru.ac.ir.
authors.forename: Nadali
authors.initials: N
authors.lastname: Babaeian Jelodar
authors.affiliation: Department of Plant Breeding, Faculty of Agriculture and Natural Resources, Persian Gulf University, Bushehr 7561158818, Bushehr, Iran. modarresi@pgu.ac.ir.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Modarresi
authors.affiliation: Department of Plant Breeding and Biotechnology, Faculty of Crop Science, Sari Agricultural Sciences and Natural Resources University, Sari 578, Mazandaran, Iran. n.bagheri@sanru.ac.ir.
authors.forename: Nadali
authors.initials: N
authors.lastname: Bagheri
authors.affiliation: The Persian Gulf Research and Study Institute, Persian Gulf University, Bushehr 7561158818, Bushehr, Iran. a.jamali111@yahoo.com.
authors.forename: Abbas
authors.initials: A
authors.lastname: Jamali
keywords: GC-MS; chamazulene; chamomile; essential oil; heat stress; salicylic acid; α-bisabolol