Genetic Variability in Ocimum L. Germplasm: Medicinal and Economic Potential for Value Addition and Product Development

Plants are essential for any ecosystem and are considered as the most important source of herbal medicine. They have been used for treatment of different diseases of human beings worldwide since the beginning of human civilization. Among the plant community, one of the genus Ocimum L. belonging to the family Lamiaceae is of high value in terms of economic upliftment and product development. Most of the species under this genus are cultivated throughout the tropical and the subtropical agro-climatic zones for medicine and for extraction of essential oils for product development in aroma-based pharmaceutical industries. The growth form of this aromatic genus Ocimum can be categorized as herbs, under-shrubs or shrubs that on distillation yield essential oils of various active aroma chemicals, such as eugenol, methyl eugenol, linalool, methyl chavicol, germacrene A and D, elemicin, s-elmene and (Z)-ocimine, and several other active constituents. These volatile compounds have a tremendous value in pharmaceutical, modern perfumery and food processing industries. Evaluation of biological activities of active ingredients of Ocimum indicated great medicinal properties, such as anti-biotic, anti-cancerous, anti-ageing, anti-stress, anti-pyretic, diaphoretic, diuretic, stomachic, anti-microbial and insecticidal, and other similar importance in herbal formulations. A survey on 40 genetic stocks (or accessions) of Ocimum available at the CSIR-CIMAP belonging to five species, viz. Ocimum basilicum L. (25: French basil 7, Sweet basil 6, Zanzibar basil 1, Indian basil 10 and Thai basil 1), Ocimum tenuiflorum L. (9: Krishna/holy basil 4 and Shyam tulsi 5), Ocimum kilimandscharicum Baker ex Gurke (1: Champhor tulsi), Ocimum africanum Lour. (2: Hoary basil) and Ocimum gratissimum L. (3: African basil/van tulsi/tree basil/clove basil), was undertaken for study. It has been observed that some selected lines of Ocimum produce high quantities of essential oils, like Ocimum tenuiflorum (O. sanctum L.) CIM-Ayu (80% eugenol) and EOH-1 (89.75% methyl chavicol). These active ingredients have high international demand for aroma-based value additions and product development from essential oils. Extension and promotion of these Ocimum species will add and contribute to the economic upliftment of the developing countries like India and elsewhere in the world.