Global Advanced Research Journal of Agricultural Science (GARJAS) ISSN: 2315-5094
September 2014 Vol. 3(9): pp. 289-297
Copyright © 2014 Global Advanced Research Journals
Full Length Research Paper
Allelopathic Potential of Essential Oils Isolated from Aromatic Plants on Silybum marianum L.
M. M. G. Saad, S. A. M. Abdelgaleil*
Department of Pesticide Chemistry and Biotechnology, Faculty of Agriculture, 21545-El-Shatby, Alexandria University, Alexandria, Egypt
*Corresponding Author’s Email: firstname.lastname@example.org;
Tel: +20-3-584-7175; Fax: +20-3-592-0067.
Accepted 08 September, 2014
The essential oils from fourteen Egyptian plants were extracted using the hydrodistillation method. Gas chromatography/mass spectroscopy (GC-MS) analysis of the isolated essential oils showed that the major constituents of the essential oils were α-pinene in Cupressus sempervirens, Syzygium cumini and Thuja occidentalis, 1,8-cineole in Callistemon viminals and Rosmarinus officinals, sabinene in Pituranthous tortuosus and Schinus terebinthifolius, β–thujone, capillene,terpinen-4-ol, pulegone, β-citronellol, α-phellandrene and trans-caryophyllene in Artemisia judaica, A. monosperma, Cupressus macrocarpa, Origanum vulgare, Pelargonium graveolens, S. molle and Vitex aguns-castus, respectively. The essential oils were tested for their inhibitory effects on seed germination and seedling growth of Silybum marianum. The phytotoxic assay results showed that the essential oil P. graveolens was the most potent inhibitor of seed germination, followed by the oils of A. monosperma, O. vulgare and A. judaica. The oil of S. terebinthifolius showed the lowest reduction of germination at all tested concentrations. On the other hand, the essential oils of P. graveolens, A. judaica and A. monosperma exhibited the highest inhibitory effect of root growth with EC50 values of 76.1,639.3 and 698.2 mg/L, respectively. In contrary, the oils of S. molle, S. terebinthifolius and R. officinals caused stimulant effect on root growth of S. marianum.Moreover, the isolated essential oils revealed a significant shoot growth reduction at all of the tested concentrations with P. graveolens and A. judaica being the most potent growth inhibitors. The results obtained suggest that, in addition to their known activities, essential oils can also serve as natural weed control products.
Keywords: Essential oils, Egyptian plants, Phytotoxic effect, Silybum marianum.