Changes in essential oil yield and composition of purple basil (Ocimum basilicum L.) genotypes under ontogenetic and morphogenetic variability

Composition of three purple basil ( Ocimum basilicum L.) genotypes were investigated. Plants were harvested three times during the pre-flowering period, twice during the full flowering period, and once during the post-flowering period. In the pre-flowering period, plants reached this stage three times within a single growing season. The purple basil genotypes reached full flowering twice during the season. The vegetation period ended before the plants harvested after flowering could reach the post-flowering stage a second time. Analyses were conducted separately on the flowers and leaves of the plants. The highest essential oil content (1.63%) was obtained from the second harvest during the pre-flowering period in the Piros genotype. The lowest essential oil content (0.15%) was detected in the flowers of the Midnight genotype during the post-flowering period and the first harvest of the full flowering period. Essential oil components were identified using gas chromatography-mass spectrometry (GC-MS). The main components of the essential oil were linalool and methyl cinnamate. The highest linalool content (71.95%) was detected in the leaves of the Piros genotype during the first harvest of the full flowering period, while the lowest linalool content (23.64%) was found in the flowers of the same genotype during the post-flowering period. The highest methyl cinnamate content (60.43%) was identified in the leaves of the Arapgir genotype during the full flowering period.