Variability in Content and Chemical Constituents of Essential Oil of Sweet Basil (<i>Ocimum basilicum</i> L.) Obtained from Aerial Plant Parts

Abstract

Sweet basil ( Ocimum basilicum L.) project that is being conducted at the National Oilseed Processing Research Institute (NOPRI) aims at exploiting the genetic diversity and associated phenotypic variation in the investigated basil germplasm and evaluating key factors such as variety, plant ontogeny and plant parts that affect yield, chemical constituents, aroma and flavor of essential oils. This paper discussed the variability inessential oils content and chemical constituents of the aerial plant parts of the basil. An open-air pot experiment was carried out using three accessions provided by Agricultural Research Corporation-Genetic Resources Unit, Sudan. The essential oils were hydro distilled from the aerial parts, flowers, leaves, stems, using Clevenger apparatus. The chemical constituents of the essential oils were determined by Gas Chromatography-Mass Spectrometry (GC-MS). As the hydro distillation yielded no oil from the stem, we present only the results for leaves and flowers. The results revealed that the essential oil content varied with a range of 0.29% to 0.33% for flowers and 0.32% to 0.48% for leaves. As usual, the content of essential oils was higher in leaves than in flowers. The Silate-Egyptian accession had the lowest essential oil content obtained from leaves and flowers. However, South Darfur accession from Sudan had the highest oil content but did not significantly differ from Kennana accession. Several oil components were identified based upon comparison of their mass spectral data with those of reference compounds published in literature or stored in a computer library. The combined GC-MS analysis showed that methyl eugenol was the major constituent of the essential oil of Kennana accession. While the major constituent of essential oil of South-Darfur and Silate-Egyptian accessions were germacrene and linalool, respectively.