Isolation and characterization of allelopathic volatiles from mugwort (Artemisia vulgaris)

Abstract

Several volatile allelochemicals were identified and characterized from fresh leaf tissue of three distinct populations of the invasive perennial weed, mugwort (Artemisia vulgaris). A unique bioassay was used to demonstrate the release of volatile allelochemicals from leaf tissues. Leaf volatiles were trapped and analyzed via gas chromatography coupled with mass spectrometry. Some of the components identified were terpenes, including camphor, eucalyptol, alpha-pinene, and beta-pinene. Those commercially available were tested individually to determine their phytotoxicity. Concentrations of detectable volatiles differed in both absolute and relative proportions among the mugwort populations. The three mugwort populations consisted of a taller, highly branched population (ITH-1); a shorter, lesser-branched population (ITH-2) (both grown from rhizome fragments from managed landscapes); and a population grown from seed with lobed leaves (VT). Considerable interspecific variation existed in leaf morphology and leaf surface chemistry. Bioassays revealed that none of the individual monoterpenes could account for the observed phytotoxicity imparted by total leaf volatiles, suggesting a synergistic effect or activity of a component not tested. Despite inability to detect a single dominant phytotoxic compound, decreases in total terpene concentration with increase in leaf age correlated with decreases in phytotoxicity. The presence of bioactive terpenoids in leaf surface chemistry of younger mugwort tissue suggests a potential role for terpenoids in mugwort establishment and proliferation in introduced habitats.

The effect of some herbal extracts and pesticides on the biological parameters of Bemisia Tabaci (genn.) (hem.: Aleyrodidae) pertaining to tomato grown under controlled conditions

“…Plants constitute a rich source of bioactive chemicals (Kim et al 2005). Monoterpenes, sesquiterpene lactones, and triterpenes are examples of such metabolites that may have commercial usage (Heywood et al 1977;Barney et al 2005). Medicinal plants not only sooth human sufferings but also are used as insecticides (Koschier and Sedy 2003).…”

Chemical Composition and Phytotoxicity of Volatile Essential Oil from Intact and Fallen Leaves of Eucalyptus citriodora

“…They possess a wide spectrum of biologi-0939Ð5075/2006/0700Ð0465 $ 06.00 " 2006 Verlag der Zeitschrift für Naturforschung, Tübingen · http://www.znaturforsch.com · D cal activities and their antibacterial, antifungal, insecticidal and pesticidal properties have made them highly sought secondary metabolites (Vokou, 1999;Isman, 2000). In addition, the volatile oil has also been implicated in allelopathic interactions suppressing the germination and growth of other plants (Lorber and Muller, 1976;Kohli, 1990;Angelini et al, 2003;Barney et al, 2005). This property of essential oils is being exploited for their use as bioherbicide (Dudai et al, 1999;Tworkoski, 2002;Singh et al, 2005).…”

Allelopathy, an alternative tool to improve cropping systems. A review

“…Barney et al (2005) isolated and identified via gas chromatography coupled with mass spectrometry a set of terpenes from fresh leaves (camphor, eucalyptol, α-pinene and β-pinene). Comparing three plant populations, these authors verified that none of the individual monoterpenes could account for the observed phytotoxicity imparted by total leaf volatiles, suggesting a synergistic effect or activity of a component not tested.…”