Xianmin Chang

Variation in the Essential Oils in Different Leaves of Basil (Ocimum basilicum L.) at Day Time

Essential oil molecules released from fresh leaves of sweet basil (Ocimum basilicum L.) were collected in Tenax traps and analysed using a TD-GC/MS. During daytime from 09.00 to 17.00, there were no differences in the con- tent and composition of total essential oils, however the percentage of eugenol increased slightly. Significant differences were found in both the total content and composition of essential oils between young and mature leaves. The total content in young leaves was four times higher than in mature leaves, with fourfold, twofold and sixtyfold differences in the rela- tive contents of linalool, eugenol and methyl eugenol respectively. There was no difference observed in the relative con- tent of 1,8-cineole. The results therefore suggest that the defining sampling procedure is important when comparing the essential oils between treatments. Key Word: Sweet basil, Ocimum basilicum, essential oil composition, linalool, eugenol, methyl eugenol, 1, 8-cineole.

New Gold in Them Thar Hills: Testing a Novel Supply Route for Plant-Derived Galanthamine

Many secondary plant compounds are synthesized in response to stressed growing conditions. We tested the feasibility of exploiting this feature in a novel strategy for the commercial production of the plant alkaloid galanthamine. Experimental lines of Narcissus pseudonarcissus were established under marginal upland permanent pasture at four different sites. Over 80% of bulbs successfully established at each site. There was no effect of altitude or planting density on galanthamine concentrations within vegetative tissues, which were higher than anticipated. The results confirm that planting N. pseudonarcissus under grass competition in upland areas could offer a novel and sustainable source of plant-derived galanthamine.

N, P and K Fertilizers Alter Plant Growth, Essential Oil Yield and Gender of Sweet Gale (Myrica gale L)

To investigate whether the fertilizers N, P or K individually affect plant growth, oil content and the gender of sweet gale, two trials, pot and field trials, were carried out at Orkney College UHI in Scotland. A pot trial was established with eight soils which were collected from different sweet gale trial sites in the north of Scotland. Although neither shoot yield nor oil concentration in shoots was affected by soil, there were significant differences in shoot yields as a result of fertilizer treatments (nitrogen (N), phosphorus (P), potassium (K) or none (control)). The best yield was obtained from the N treatment which was double to that of the control and P treatments. N, P or K fertilizers did not consistently affect shoot oil concentration in two seasons; however, oil yield was significantly affected, and N treatment produced two-three fold oil yield increases compared with the control or P treatment. In the N treatment, the increase in shoot yield was positively correlated with total nitrogen or nitrate nitrogen in the soil, suggesting the occurrence of a nitrogen priming effect. Data suggested that as shoot yield increased the oil concentration in shoots decreased. Neither soil nor N, P or K fertilizers had a significant effect on oil composition. Amongst fertilizer treatments, P resulted in the largest number of plants changing gender from female to male. A field N trial confirmed that nitrogen significantly enhanced the shoot yield of young plants.