title: Chemical composition and inhibitory activity of essential oil from decaying leaves of Eucalyptus citriodora.
abstract: A study was undertaken to explore the content and composition of volatile oil from decaying leaves of lemon-scented eucalypt (Eucalyptus citriodora Hook.) not analyzed earlier. GC and GC-MS analysis of the oil (yield 0.6%) revealed the monoterpenoid nature with citronellal (52.2%), citronellol (12.3%) and isoisopulegol (11.9%) as the major constituents. Overall, 17 components were identified that accounted for over 94% of the decaying leaf oil. Surprisingly, the decaying leaf oil contained nearly 1.8% of trans-rose oxide, which is generally absent in eucalypt essential oil. Decaying leaf oil and its major 2 components (citronellal and citronellol) inhibited the germination and root elongation of two weeds--Cassia occidentalis (broad-leaved) and Echinochloa crus-galli (grassy weed). Based on the dose-response studies, I50 values were determined for decaying leaf oil and the effect was more on germination only of broad-leaved weed (C. occidentalis), whereas that of citronellal and citronellol were on germination as well as root length of E. crus-galli (grassy weed). Based on I50 values it was observed that citronellal was more phytotoxic and germination inhibiting in nature, whereas citronellol was a more potent root inhibitor, thereby indicating a possible different mode of action. The study concludes that decaying leaf oil hold a good commercial value for exploitation as weed management agent.
authors.affiliation: Department of Botany, Panjab University, Chandigarh 160014, India.
authors.forename: Daizy R
authors.initials: DR
authors.lastname: Batish
authors.forename: Harminder Pal
authors.initials: HP
authors.lastname: Singh
authors.forename: Nidhi
authors.initials: N
authors.lastname: Setia
authors.forename: Shalinder
authors.initials: S
authors.lastname: Kaur
authors.forename: Ravinder K
authors.initials: RK
authors.lastname: Kohli
mesh_terms: D005052:Eucalyptus / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D018525:Germination / Q000187:drug effects; D009822:Oils, Volatile / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D063245:Plant Development; D018515:Plant Leaves / Q000737:chemistry*; D010944:Plants / Q000187:drug effects; D014197:Trees
chemical_list: D009822:Oils, Volatile