Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 3.29

ANALYSIS OF ESSENTIAL OIL PRODUCTION IN VETIVERIA ZIZANIOIDES (L.) NASH DURING EARLY GROWTH

D.R. MASSARDO*, M. CAPUANO**, F. SENATORE**, L. DEL GIUDICE*

*) Istituto di Genetica e Biofisica “Adriano Buzzati-Traverso” – CNR, via G. Marconi 10, 80125 Napoli

**) Dip.to Chimica delle Sostanze Naturali, Università “Federico II”, via D. Montesano 49, 80131 Napoli

Vetiver oil, gas chromatography/mass, khusimone, khusimol, symbiotic bacteria

The species Vetiveria zizanioides (L.) Nash (Gramineae) is known for its ability to produce odorous roots, which can be used for the extraction of an essential oil of great economic importance (Maffei 2002). The essential oil that is produced in secretory cells located inside the mature roots has been used since ancient times as a perfume and a natural remedy against human and animal disease. It consists of a complex mixture of sesquiterpene hydrocarbons and alcohols, which are mostly used as a basic material for perfurmery.

Recently has been reported the electron microscope analysis of vetiver cells of the roots, evidencing the presence of bacteria into lysigen lacunae, which are cellular structure of the vetiver roots in which is stored the essential oil (Maffei 2002). The close relationship between those bacteria and the essential oil stimulated the idea of a direct involvement of those symbiotic bacteria in the essential oil metabolism.

As a preliminary work, in a tentative to gain on insight to essential oil metabolism we have analyzed the oil production in vetiver during early growth.

Planting of Vetiveria zizanioides in Campania region was performed in the spring using vetiver culmus with short roots and with approximately 20 cm of leaves. Root samples were collected at intervals of two months starting from transplantation. The freshly collected roots were cut into small pieces, then hydrodistilled for 3 hours according to the standard procedure as described in the European Pharmacopoeia (1997), using a Clevenger-type apparatus to produce oil. The essential oil was analyzed by GC and GC/MS. GC analyses were performed on a Perkin-Elmer Sigma-115 gas chromatograph equipped with a DB-5 fused-silica column, injector and detector temperatures 250°C and 285°C, respectively; He as carrier gas. CG/MS analysis was performed using a Hewlett-Packared 5890A apparatus,equipped with a HP-1 fused-silica column, linked on line with a HP Mass Selective Detector (MSD 5970 HP); ionization voltage 70eV; electron multiplier energy 2000 V.

The production of vetiver oil was constant, 0,30 g oil/100 g roots, during the first 6 months (from May to October) growth from transplantation. During 8 months growth there was a doubling of production of essential oil, 0,70 g oil/100 g roots, before starting in turn a continuous decrease of oil production: during 10 months growth it was 0,6 g oil/100 g. roots; while during 12 months growth it was 0,30 g oil/100 g roots. Besides, the analysis of two principal vetiver oil costituents, the tricyclic sesquiterpenes khusimone and khusimol has shown that both the latter components maintain costant their rate percent in the vetiver oil during the growth from transplantation.

Our data suggest that vetiver oil production is closely related to the metabolism of plant which is affected by changes in environmental temperatures (Maffei 2002). During winter time the drop in temperature causes a decrease of plant metabolic activities which in turn slow down oil production.

It could suppose that also symbiotic bacteria are affected by changes in environmental temperatures so that their activity in metabolizing vetiver essential oil is related to the modulation of plant metabolism.

Work is in progress to isolate symbiotic bacteria from vetiver roots.

References

- M. Maffei (2002). Introduction to the genus Vetiveria. In “Vetiveria . The genus Vetiveria” (ed. M. Maffei), 1-18. Taylor & Francis, London and New York.

- European Pharmacopoeia 3^th Ed., p. 121, Council of Europe, Strasbourg (1997)