Abstract:
The genus Ocimum is a member of the Lamiaceae family which contains about 150 species
of herbs and shrubs. Majority of species of genus Ocimum are essential oil bearing plants.
Several species belonging to genus Ocimum are distributed in Sri Lanka. In the present study
attempts were made to investigate the essential oils of populations distributed in 5 districts of
Sri Lanka. Survey was conducted Anuradhapura, Matale, Gampaha, Kurunegala and
Puttalam districts and 9 different samples (APMI 3, APMI 4, MLLD 2, MLLD 5, MLLD 6,
KGYP 2, KGYP 5, GPLG 5, and PTWW 2) were collected, Species were authenticated by
comparing with National Herbarium. These samples were air dried for 3 days and cut into
small pieces (2cm) and hydro distilled using Clevenger apparatus. Essential oil composition
was determined using GC-MS analysis. Cluster analysis for essential oil composition was
carried out by using SPSS version 14. Oil content varied from 0.4% to 1.6% depending on
the locality and the population. The highest oil content was reported from Loluwagoda
(GPLG 5) in Gampaha district while the lowest was from Yaggapitiye, in Kurunegala district.
Eugenol content varied from 1.45% (APMI 4) to 86.33% (GPLG 5). Methyl eugenol,
Camphor, was only found in APMI 4 (85.64%) and APMI 3 (37.99%) respectively as the
main component. Germacrene-d and Caryophyllene are common compounds of all the
populations except APMI 3. Ocimine was found in 6 species except APMI 3, APMI 4, and
MLLD 6. Thirty six compounds were identified from nine species. All populations were
clustered into two on the basis of availability of different compounds using hierarchical
cluster analysis. Cluster 1 consisted of 3 populations (MLLD 5, GPLG 5, KGYP 5) while
cluster 2 consisted of 6 populations ( MLLD 2, KGYP 2, PTWW 2, APMI 3, APMI 4, and
MLLD 6). Information generated through the present study could be of vital importance for
chemotaxonomy of Ocimum populations.
