Abstract

Exposure of basil plants (Ocimum basilicum) in a controlled environmental room temperature to supplementary UV-B light for 3 h per day in the early morning over a period of two weeks resulted in shorter plants with higher dry matter, thicker leaves and more axillary shoots. Supplementary UV-B did not affect plant leaf area or number of leaf-pairs; however, specific leaf area was significantly increased due to increase in leaf thickness. Analysis of volatile oils by TD-GC/MS in fresh leaf samples harvested after one and two weeks of treatment showed that UV-B also stimulated the synthesis of the phenyl-propanoid, eugenol and the terpenoids 1, 8-cineole and linalool. There was no effect on volatile oil composition.

Key words: Ocimum basilicum, basil, growth, essential oil composition, 1, 8-cineole, linalool, eugenol, UV-B.