Effect of Compost and Titanium Dioxide Application on the Vegetative Yield and Essential Oil Composition of Coriander

Coriander is one of the most popular and intensely used spices owing to its multipurpose uses worldwide. It is mainly cultivated for the production of its dried seed and fresh leaves. The present study aimed to evaluate the application of compost and foliar spraying of TiO2 on the yield and essential oil composition of coriander. Two field experiments were conducted during two successive seasons; after that, the yield parameters were determined, and the essential oil of the seeds was extracted and analyzed via gas chromatography-mass spectrometry (GC-MS). Results indicated that coriander growths at both years were significantly affected by compost application and foliar application of TiO2, and a significant interaction of these two factors also occurred. Compost application at 50 m3 caused significant increments of 55% and 46% in umbels number and 75% and 64% in seed yield in the first and second season, respectively, compared with control. The application of compost to the coriander plant significantly influenced oil percentage and oil yield per ha. The maximum oil percent was recorded in control plants. Foliar application of TiO2 resulted in significant improvement in plant height, number of umbels, and seed yield of coriander as compared with control and reached their maximum values at 6 g L−1 compared with the control; foliar application of TiO2 at 2 g L−1 enhanced numbers of umbels by 22% with no significant differences between 2, 4, and 6 g L−1 treatments in the first season and by 24, 33, and 48% in the second season. Increases in seed yield accounted for 34, 43, and 64% in the first season and 21, 36, and 45% in the second season due to titanium dioxide application of 2, 4, and 6 g L−1, respectively. The maximum content of linalool (87.61%) and minimum content of estragole (0.7%) was recorded at 4 g L−1 titanium dioxide with no compost.

Pheno-Morphological and Essential Oil Composition Responses to UVA Radiation and Protectants: A Case Study in Three Thymus Species

Solar ultraviolet (UV) radiation mainly includes UVA (320–400 nm). UVA intensity varies depending on the season and geographic location, while it is projected to rise owing to climate change. Since it elicits secondary metabolism, additional knowledge on the UVA dependence of phytochemical production is required for both farmers and processors, particularly under natural settings. In this field study, the pheno-morphological traits and essential oil composition responses to UVA intensity were addressed in three Thymus species [T. daenensis (endemic to Iran), T. fedtschenkoi (semi-endemic), T. vulgaris (common thyme)]. During growth, three UVA levels (ambient, enriched, excluded) were realized in combination with spraying protectants [water (control), melatonin, glutathione, iron-zinc nanofertilizer]. In T. daenensis, enriched UVA caused early flowering. The height of T. daenensis was the longest under enriched UVA, and the shortest under excluded UVA. In control plants, enriched and excluded UVA stimulated the accumulation of oxygenated metabolites in T. daenensis and T. fedtschenkoi. Altogether, under enriched UVA some phenolic compounds (e.g., thymol, carvacrol, γ-terpinene) increased in the essential oil of all three species, but others decreased. In all taxa, glutathione caused a significant essential oil content reduction. Iron-zinc nanofertilizer increased essential oil accumulation in T. daenensis and T. vulgaris. Treatments also induced an alteration of the essential oil composition. In conclusion, cultivation regime effects on the essential oil quality (composition) and quantity were strongly species dependent. T. deanensis underwent the most consistent enhancement under UVA, making the species more adaptable to climate change, whereas T. fedtschenkoi the least.

ESSENTIAL OIL COMPOSITION OF TWO SPECIES OF SCUTELLARIA AERIAL PARTS

The chemical composition of essential oils obtained by hydrodistillation method from two plants of the genus Scutellaria, grown in Uzbekistan and used in folk medicine were comparatively investigated by GC/MS and FID. Overall individually thirty three constituents were identified in both of aerial parts of S. adenostegia and S. comosa essential oils, representing 94.4 and 97.0% of the total, respectively. The main components were determined as acetophenone (24.2%), eugenol (12.3%), caryophyllene oxide (8.9%), and β-caryophyllene (7.0%) in the oil of S. adenostegia. β-Caryophyllene (12.5%), phytol (11.4%), linalool (11.1%), acetophenone (10.4%), caryophyllene oxide (6.6%),1-hexanol (5.3%), and (E)-2-hexenal (5.1%) were found as major components in the S. comosa oil. The composition of the oils of S. adenostegia and S. comosa was being reported for the first time. The essential oils of S. adenostegia and S. comosa showed significant antimicrobial properties against Bacillus subtilis, moderate effect against Salmonella enterica and Escherichia coli.

Short-term changes related to autotetraploidy in essential oil composition of Eucalyptus benthamii Maiden & Cambage and its applications in different bioassays

Some forest trees have been polyploidized to improve their traits and to supply new germplasms for breeding programs. As trees have a long juvenile stage, the early characterization of the chromosome set doubling effects is crucial for previous selection. Thus, we aimed to characterize the chemical variability of essential oils from diploid and autotetraploid germplasms (autotetraploid A and B) of Eucalyptus benthamii, as well as to evaluate their larvicidal and allelopathic effects. Autotetraploid A showed a higher essential oil yield than diploid and autotetraploid B, which did not differ quantitatively. Aromadendrene, viridiflorol and α-pinene were the major compounds in the diploid essential oil. In contrast, compounds were present in autotetraploids, such as 1,8-cineole, limonene, α-terpineol, and α-terpinyl-acetate. Essential oils from the diploid at 50–200 ppm were twice as larvicidal than those from autotetraploids against Aedes aegypti larvae. Considering the phytotoxicity bioassays using Lactuca sativa, essential oils from both ploidy levels affected root growth. Moreover, the essential oils inhibited shoot growth at all concentrations tested (187.5; 375; 750; 1500; and 3000 ppm). Autotetraploid A and B had the same effect on shoot growth as glyphosate. The essential oils had no cytogenotoxic effect on root meristematic cells of L. sativa, whereas phytotoxic potential was identified mainly in shoot growth. This work demonstrated a dramatic change in secondary metabolism (terpene composition) related to an increase in the ploidy level in Eucalyptus germplasms. In addition, we report the novelty of the chemical composition of essential oils among germplasms and their potential use as larvicidal and post-emergence weed control agents.

Effect of hydrogen peroxide treatment on the concentration of volatile compound in coriander seeds oil

Coriander seeds essential oil have shown some remarkable biological properties and health benefits. The coriander seeds used in Indonesia are imported and also treated with hydrogen peroxide before reaching consumers. Hydrogen peroxide is known to be a strong oxidizer, but so far, there has been no information that explains its effects on the essential oil composition and concentration in coriander seed. This study aims to determine the effect of using hydrogen peroxide and the drying method on the composition of essential oils in coriander seeds. Yield and volatile oil compounds were measured, and the results were compared between the hydrogen peroxide concentration (0,35 and 50% ) and drying method (mechanical drying (50 ℃) and room temperature drying). GC-MS analysis detected linalool as the most common volatile constituent in all treatments. The highest concentration of linalool compounds (70.16%) was found in seeds without hydrogen peroxide (0%) treatment combined with mechanical drying, followed by without hydrogen peroxide (0% H2O2) combined with room drying (23.74%), then by 35% hydrogen peroxide combined with room drying (18.71%), 35% hydrogen peroxidecombined with mechanical drying (18.84%), 50% hydrogen peroxide combined with room drying (22.18%) and by 50% hydrogen peroxide combined with mechanical drying (15.45%). Therefore, the yield was clearly affected only by hydrogen peroxide treatment where no hydrogen peroxide treatment gave the highest yield. The drying method did not have any significant effect on yield.