Humic Acid Improves Plant Yield, Antimicrobial Activity and Essential Oil Composition of Oregano (Origanum vulgare L. subsp. hirtum (Link.) Ietswaart)

To investigate the influence of stress modulators on the adaptive physiological responses and biomass traits of oregano under water stress conditions, a two-year (2018 and 2019) randomized complete block-designed factorial research was performed. In this study, oregano plants were treated with five stress modulators levels (CHN: chitosan, AMA: amino acids, SEW: seaweed, ASA: ascorbic acid, SAA: salicylic acid, and CON: control) at three levels of irrigation regimes (Irr40 (40), Irr60 (60) and Irr75 (75) % field capacity). The effects of water shortage and biostimulant application were evaluated on total dry weight (TDW), relative water content (RWC), essential oil production, chlorophyll, nutrient (N, K, and P), proline, total soluble sugar, polyphenol and flavonoid content, and activity of antioxidant enzymes. The result showed that under optimal irrigation conditions, oregano plants sprayed with CHN exhibited the highest dry weight (141.23 g m−2) as a morphological trait, the highest relative water content (79.34%), the most consistent concentrations of nitrogen, phosphorus and potassium (3.14, 0.39, and 1.69%, respectively), chlorophylls a and b (3.02 and 1.95 mg g−1 FW, respectively), and total phenols and total flavonoids (30.72 and 3.17 mg g−1 DW, respectively). The water deficit increased the proline content, with the greatest amount (4.17 μg g−1 FW) observed in control plants. Moreover, under moisture shortage stress conditions, the application of CHN and SEW increased the soluble sugar (27.26 μmol g−1 FW) and essential oil yield (1.80%) production, the catalase, ascorbate peroxidase, and superoxide dismutase activities (3.17, 1.18, and 63.89 μmol min−1 g−1 FW, respectively) compared to control plants. In summary, the study demonstrated that oregano plants respond positively to stress modulator treatments when subjected to moisture shortage stress, especially when treated with chitosan. The results offer promising insights for developing sustainable adaptative strategies aimed at enhancing the oregano’s tolerance to water shortage, ultimately improving its productivity and biochemical traits.

Section: Introductionmentioning

confidence: 99%

The Role of Stress Modifier Biostimulants on Adaptive Strategy of Oregano Plant for Increasing Productivity under Water Shortage

Abdali,

Rahimi,

Siavash Moghaddam

et al. 2023

“…Mass spectra were taken at 70 eV with a mass range of m/z 35–450. The GC oven temperature was kept at 60 °C for 10 min and programmed to be 220 °C at a rate of 4 °C/min and kept constant at 220 °C for 10 min and then programmed to be 240 °C at a rate of 1 °C/min [ 68 ].…”

Section: Methodsmentioning

confidence: 99%

The Effect of Irrigation and Humic Acid on the Plant Yield and Quality of Sweet Basil (Ocimum basilicum L.) with Mulching Application under Semi-Arid Ecological Conditions

Sayarer

Aytaç

Kürkçüoğlu

2023

Self Cite

The adoption of suitable irrigation levels (IRL), humic acid doses (HAD) and soil mulching (SM) are important tools for improving the morpho-physiological and biochemical traits of medicinal and aromatic plants. Ocimum basilicum L. cultivated under four IRL: IRL 100 = 100% FC–IRL 75 = 75% FC–IRL 50 = 50% FC–IRL 25 = 25% FC and four HAD: HA 0 = 0.0 Lha−1–HA 10 = 10.0 Lha−1–HA 20 = 20.0 L ha−1–HA 40 = 40.0 L ha−1 were applied in order to evaluate morpho-physiological and biochemical traits under the ecological conditions of Eskişehir in 2016 and 2017. A second trial was conducted with black plastic soil mulch (SM) and compared with the control plots (CP) in 2016. The experiment was arranged in a randomized complete block design with split plots and three replications. The plant height (PH), fresh herb yield (FHY), dry herb yield (DHY), dry leaf yield (DLY), protein ratio (PR), and main essential oil compounds (MEOC) of Ocimum basilicum L. increased and the essential oil ratio (EOR) and essential oil yield (EOY) decreased with increasing IRL (IRL 100 and IRL 75). FHY (7268.3 and 7472.7 kg ha−1) and DLY (635.3 and 637.5 kg ha−1) increased with increasing HAD (HA 20 and HA 40) compared to the values of FHY and DLY at HA 0 (6852.6 and 587.0 respectively). The SM application at IRL 50 increased the PH between 8.8 and 13.5%, FHY 11.7 and 16.7%, DLY 22.5 and 29.2%, and at IRL 75 the EOY between 20.0 and 23.9% compared to CP. In addition, PH, FHY, DLY, and EOY were highest at HA 40 and HA 20. The MEOC (linalool, 1,8-cineole, and (E) – β-bergamotene) under SM were more pronounced at IRL 25 and IRL 50 compared to CP. HA particularly improved FHY, DLY, and the main essential oil compounds that can be considered plant biostimulants, which were defined by several studies and regulations.

“…Few reports on chemical composition and biological activities of the EO of O. heracleoticum are available in the literature [ 17 , 27 , 28 , 29 , 30 ]. Napoli and coworkers reported data on variation in the aromatic profile of essential oils from a 3-year cultivation trial of Origanum vulgare subsp.…”

Section: Introductionmentioning

confidence: 99%

“…A study on Origanum vulgare subsp. hirtum from Turkey rich in carvacrol and γ-terpinene showed that this EO could be used to combat increasing resistance to antibiotics and can be an alternative in the food preservation [ 28 ].…”

Section: Introductionmentioning

confidence: 99%

Origanum heracleoticum Essential Oils: Chemical Composition, Phytotoxic and Alpha-Amylase Inhibitory Activities

Amato

Caputo

Francolino

et al. 2023

Many studies have demonstrated the herbicidal effects of several essential oils and their possible use as substitutes for chemical herbicides. Several enzymes play a very significant role in seed germination: among these, α-amylase could be involved in essential oil phytotoxic processes. The aims of this study were to compare the chemical composition of the essential oils of two ecotypes of O. heracleoticum growing in Cilento (Southern Italy) and to study their possible use as natural herbicide using Raphanus sativus, Sinapis arvensis and Lolium multiflorum seeds. Moreover, a possible inhibitory activity on the α-amylase enzyme extracted from germinating seeds was evaluated as a possible mechanism of action. Both oils, characterized by GC-MS, belonged to a carvacrol chemotype. The alpha-amylase activity was determined using DNSA (dinitrosalicylic acid) assay quantifying the reducing sugar produced. Furthermore, the essential oils demonstrated phytotoxicity at the highest dose tested, and an inhibitory effect on α-amylase, probably correlated with the phytotoxic effects, was registered. The oils showed interesting phytotoxic and alpha-amylase inhibitory activities, which deserve to be further investigated.