Basil Cultivars Research Articles

Salt-Induced Stress Impacts the Phytochemical Composition and Aromatic Profile of Three Types of Basil in a Genotype-Dependent Mode.

Basil (Ocimum basilicum L.) is among the most widely used aromatic plants of Lamiaceae, often grown in areas where salinity is an adverse factor. Most studies on the effect of salinity on basil focused on the influence of salt stress on productive traits, while few reported on how it affects the phytochemical composition and the aroma profile. Three basil cultivars (Dark Opal, Italiano Classico, and Purple Ruffles) were grown hydroponically for 34 days with two nutrient solutions that differed in NaCl concentration [no NaCl (Control) and 60 mM NaCl]. Yield, secondary metabolite concentration (β-carotene and lutein), antioxidant activity [1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reduction antioxidant power (FRAP)], and aroma profile based on composition of volatile organic compounds (VOCs) were appraised in response to salinity applications. Salt stress significantly reduced fresh yield in Italiano Classico and Dark Opal by 43.34 and 31.69%, respectively, while no effect was observed in Purple Ruffles. Furthermore, the salt-stress treatment increased β-carotene and lutein concentrations, DPPH, and FRAP activities, and the total nitrogen content of the latter cultivar. CG-MS analysis revealed significant differences in VOCs composition of the basil cultivars, with Italiano Classico and Dark Opal characterized by the predominance of linalool (average 37.52%), which, however, was negatively affected by salinity. In Purple Ruffles, the predominant VOC compound, estragole (79.50%), was not affected by the deleterious effects of NaCl-induced stress.

Effect of Low Water Availability on Seed Yield and Seed Quality of Basil (Ocimum basilicum).

Basil (Ocimum basilicum L.) is an aromatic and medicinal plant with important properties and is used as an alternative crop in many countries of the world because of its medicinal, economic, industrial, and nutritional importance. The objective of the present study was to determine the effect of low water availability on seed production and seed quality of five cultivars of basil (Mrs Burns, Cinnamon, Sweet, Red Rubin, and Thai). Irrigation levels and cultivars affected seed yield and thousand seed weight. In addition, plants that were exposed to low water availability produced seeds that germinated in a greater percentage. Additionally, root length was increased as the PEG concentration was increased in the germination solution and was affected by the low water availability of the mother plants. The length of the shoot, the length of the root and the seed vigor could not be used as indicators of low water availability on the mother plants, but these characteristics and especially the seed vigor could be used as indicators of low water availability of the seed. Furthermore, the root length and the seed vigor indicated that there is a possibility of an epigenetic effect of water availability on the seed produced under low water availability, though more work is needed.

Volatiles Emitted by Three Genovese Basil Cultivars in Different Growing Systems and Successive Harvests

The Genovese basil (Ocimum basilicum L.) is the essential ingredient in “pesto” sauce, and it has always had ample use in Mediterranean gastronomy. This horticultural type of basil is grown in the open field and harvested more than once during its cultivation cycle, but in recent decades it is increasingly grown using alternative cultivation methods (e.g., soilless cultivation) that guarantee higher and more uniform production. The dataset presented in this contribution refers to the analysis of the aroma profile by solid-phase microextraction and gas chromatography coupled with a mass spectrometer, of three different cultivars of Genovese basil (Aroma 2, Eleonora, and Italiano Classico) grown in the open field or floating raft system in two successive harvests. The data are a record of the variability of volatile organic compounds due to key agronomic factors, such as the genotype, the cultivation method, and the cut. They may be of interest for those concerned about the impact of different technical factors on the aroma and flavor of basil plants.

Growth and Biochemical Characters of Basil (Occimum basilicum) in Response to Low Irrigation and UV-B

Various basil cultivars in greenhouse can be cultivated round all year with the necessary growth conditions. Environmental stresses such as low irrigation and ultraviolet radiation are among the factors affecting the plant growth and development process. In the current study, five treatments for duration of ultraviolet radiation (0, 5, 10, 15, 20 minutes per day) and four irrigation levels (100, 75, 50, 30 % of field capacity) on two green and violet type of basil based on factorial in a completely randomize design experiment was conducted. The results showed that the duration of UV irradiation, low irrigation stress and their interaction effected morphological and biochemical responses of both basil cultivars. Measured traits such as leaf thickness, secondary metabolites, percent of essential oil, sodium and potassium elements content under UV treatments, low irrigation stress, and their interactions significantly increased compared to the control, but inter-nod decreased due to ultraviolet radiation, low irrigation stress and interaction effects. The amount of soluble sugars increased due to low irrigation stress (especially relatively severe low irrigation stress, 50% FC), but decreased due to high levels of UV treatments compared to the control, according to the result, UV radiation and low irrigation stress had shown synergistically stat together. The purpose of this study was to investigate the effects of UV light duration (280–320 nm), low irrigation stress, and the combined effects of UV light duration and low irrigation stress on morphological and biochemical responses of two basil cultivars.

Otimização crescimento in vitro de manjericão usando lâmpadas LED

ABSTRACT: Tissue culture is an important technique for assessing the influence of light on plant growth. This study evaluated the in vitro cultivation of Ocimum basilicum cultivars under different light sources. First, an experiment was conducted to evaluate the effect of fluorescent and LED (Light Emitting Diode) light sources (yellow, blue, green, and red) on five basil cultivars (Cinnamon, Grecco a Palla, Italian Large, Limoncino, and Maria Bonita), followed by, another experiment, with two LED lights (Growlux and Blue). In vitro basil plants did not exhibit good growth under yellow lamps. The size of the roots of Cinnamon, Grecco a Palla and Limoncino cultivars under the two light conditions were similar. Moreover, the luminous condition of the Growlux lamps generated a greater quantity of leaves and fresh, and dry weight than blue LED lamps for Cinnamon, Grecco a Palla and Limoncino cultivars. Thus, it was concluded that the Growlux lamps promoted a greater amount of basil biomass.

Phenological development and production potential of different cultivars of holy basil (Ocimum sanctum) in lower hills of Uttarakhand

Phenological development and production potential of different cultivars of holy basil (Ocimum sanctum) in lower hills of Uttarakhand

Zinc biofortification of Genovese basil: Influence on mineral profile and estimated daily intake in adults and children

Despite the well-known beneficial function of Zn in human health, its deficiency is an increasingly recognized worldwide concern. In this work, we evaluated the agronomic biofortification of two basil (Ocimum basilicum L.) cultivars (‘Aroma 2’ and ‘Eleonora’) using nutrient solutions with different Zn concentrations (0, 12.5, 25, 37.5, and 50 µM). We focused on the impact of biofortification on the mineral profile quantified by ICP OES. Compared to the control, biofortification treatments increased Zn concentration by 22.03 % (on average). Consumption of one serving of 50 µM of Zn biofortified basil ‘Aroma 2’ guarantees an estimated daily intake (EDI) of 275.746 and 91.915 µg day−1 in adults and children, respectively. Furthermore, Zn biofortification positively affected the mineral profile of the leaves. Compared to the control, the B50 dose of Zn (50 μM of Zn) increased the EDI of macro and microelements in adults and children. This aspect highlights how biofortified basil consumption would improve consumers’ nutritional status.

Morphological, Physiological and Quality Performances of Basil Cultivars under Different Fertilization Types

The prospect of replacing traditional chemical fertilization with organic and microorganism-based fertilization meets the current demand for more sustainable cropping systems and healthy food. In this respect, research was carried out to evaluate the effects of the factorial combination between four basil cultivars (‘Aromat de Buzau’, ‘Macedon’, ‘Cuisoare’ and ‘Serafim’) and three types of fertilization, namely chemical fertilization (with a solid chemical fertilizer), organic fertilization (with chicken manure formulate) and microorganisms’ fertilization (with microorganisms formulate), on basil yield, biochemical and physiological parameters and essential oil composition. The results showed that the biometric parameters (plant height, number of stems and leaves and leaf area) were significantly influenced by the cultivar; ‘Macedon’ obtained the highest values of plant height (64.7 cm) and number of stems (20.33) and leaves (618.3) and ‘Serafim’ the largest leaf area (4901.7 cm2 per plant), while the type of fertilization did not affect these parameters. Regarding the biomass, the influence of the cultivar was not significant on fresh biomass but was significant on dry biomass, with ‘Macedon’ showing the highest value (56.4 g·plant−1 dry biomass). The mentioned parameters were significantly influenced by the type of fertilization, with the highest values recorded with chemical fertilization. Both the cultivar and the fertilization type significantly influenced the physiological parameters (the total content of assimilatory pigments and photosynthesis). Five phenolic compounds were quantified from leaf extracts by HPLC-MS (caffeic acid, hyperoside, isoquercitrin, rutin and quercitrin). Hyperoside was identified only in ‘Macedon’, while the rest of the compounds were found in all the cultivars and varied depending on the cultivar and fertilization type. Regarding the composition of the essential oil, variation was found depending on the cultivar and fertilization type. In ‘Aromat de Buzau’, the main compounds were methyl chavicol and β-linalool; in ‘Macedon’, geranial and neral; and in ‘Cuisoare’ and ‘Serafim’, β-linalool. Moreover, the PCA showed that the ‘Serafim’ cultivar has exclusive properties compared to the other cultivars. Our results highlight that identifying the most effective interaction between genotype and fertilization type allows to optimize yield and quality targets for sweet basil.

The impact of drought stress on antioxidant activities of basil (Ocimum basilicum) cultivars extracts

The impact of drought stress on antioxidant activities of basil (Ocimum basilicum) cultivars extracts

Facing energy limitations - approaches to increase basil (Ocimum basilicum L.) growth and quality by different increasing light intensities emitted by a broadband LED light spectrum (400-780 nm).

Based on the current trend towards broad-bandwidth LED light spectra for basil productions in multi-tiered controlled-environment horticulture, a recently developed white broad-bandwidth LED light spectrum (400-780 nm) including far-red wavelengths with elevated red and blue light fractions was employed to cultivate basil. Four Ocimum basilicum L. cultivars (cv. Anise, cv. Cinnamon, cv. Dark Opal and cv. Thai Magic) were exposed to two different rising light intensity conditions (ILow and IHigh). In dependence of the individual cultivar-specific plant height increase over time, basil cultivars were exposed to light intensities increasing from ~ 100 to ~ 200 µmol m-2 s-1 under ILow, and from 200 to 400 µmol m-2 s-1 under IHigh (due to the exponential light intensity increases with decreasing proximity to the LED light fixtures). Within the first experiment, basils' morphological developments, biomass yields and time to marketability under both light conditions were investigated and the energy consumptions were determined to calculate the basils' light use efficiencies. In detail, cultivar-dependent differences in plant height, leaf and branch pair developments over time are described. In comparison to the ILow light conditions, IHigh resulted in accelerated developments and greater yields of all basil cultivars and expedited their marketability by 3-5 days. However, exposure to light intensities above ~ 300 µmol m-2 s-1 induced light avoidance responses in the green-leafed basil cultivars cv. Anise, cv. Cinnamon and cv. Thai Magic. In contrast, ILow resulted in consumer-preferred visual qualities and greater biomass efficiencies of the green-leafed basil cultivars and are discussed as a result of their ability to adapt well to low light conditions. Contrarily to the green-leafed cultivars, purple-leafed cv. Dark Opal developed insufficiently under ILow, but remained light-tolerant under IHigh, which is related to its high anthocyanin contents. In a second experiment, cultivars' volatile organic compound (VOC) contents and compositions over time were investigated. While VOC contents per gram of leaf dry matter gradually decreased in purple-leafed cv. Dark Opal between seedling stage to marketability, their contents gradually increased in the green cultivars. Regardless of the light treatment applied, cultivar-specific VOC compositions changed tremendously in a developmental stage-dependent manner.

Morpho-Physiological and Biochemical Responses of Hydroponically Grown Basil Cultivars to Salt Stress

Depending on duration and magnitude, abiotic stresses interfere with plant metabolic processes and may severely impact developmental and qualitative attributes. In this study, in addition to characterizing three different cultivars of basil ('Anise', 'Cinnamon', and 'Lemon') grown under hydroponics, we appraised the impact of NaCl salt stress (60 mM) on morphophysiological and nutraceutical properties of the basil crop. Salt stress significantly reduced fresh yield (51.54%, on average) and photosynthetic parameters (ACO2, E, and gs) in all cultivars by raising tissue concentrations of Na+ and Cl-. In addition to reducing the concentration of nitrate (77.21%), NaCl salt stress increased the concentrations of key bioactive molecules, notably carotenoids (lutein and β-carotene), phenolic acids, and flavonoid derivatives, thus resulting in a higher antioxidant activity of salt-treated basil plants compared to the untreated ones. Analysis by UHPLC revealed that cichoric acid was the most abundant polyphenolic compound in all basil cultivars, with the highest values recorded in 'Cinnamon'.

Zinc biofortification of hydroponically grown basil: Stress physiological responses and impact on antioxidant secondary metabolites of genotypic variants.

Ocimum basilicum L. is an aromatic plant rich in bioactive metabolites beneficial to human health. The agronomic biofortification of basil with Zn could provide a practical and sustainable solution to address Zn deficiency in humans. Our research appraised the effects of biofortification implemented through nutrient solutions of different Zn concentration (12.5, 25.0, 37.5, and 50 µM) on the yield, physiological indices (net CO2 assimilation rate, transpiration, stomatal conductance, and chlorophyll fluorescence), quality, and Zn concentration of basil cultivars 'Aroma 2' and 'Eleonora' grown in a floating raft system. The ABTS, DPPH, and FRAP antioxidant activities were determined by UV-VIS spectrophotometry, the concentrations of phenolic acids by mass spectrometry using a Q Extractive Orbitrap LC-MS/MS, and tissue Zn concentration by inductively coupled plasma mass spectrometry. Although increasing the concentration of Zn in the nutrient solution significantly reduced the yield, this reduction was less evident in 'Aroma 2'. However, regardless of cultivar, the use of the maximum dose of Zn (50 µM) increased the concentration of carotenoids, polyphenols, and antioxidant activity on average by 19.76, 14.57, and 33.72%, respectively, compared to the Control. The significant positive correlation between Zn in the nutrient solution and Zn in plant tissues underscores the suitability of basil for soilless biofortification programs.

Physiological responses and variation in secondary metabolite content among Thai holy basil cultivars (Ocimum tenuiflorum L.) grown under controlled environmental conditions in a plant factory.

Holy basil (Ocimum Tenuiflorum L.) is a widely used herb containing several bioactive compounds of interest for the food and pharmaceutical industries. Plant factories using artificial lighting (PFAL) is a modern agricultural system that offers opportunity to improve crop production and stabilizes productivity in many herbal plants. However, little is known about the variation among holy basil varieties that can be cultivated and provide reasonable biomass and bioactive compounds in PFAL. We therefore evaluated 10 Thai accessions and two commercial cultivars in a PFAL (with hydroponic cultivation) to categorize cultivar characteristics by investigating physiological responses and secondary metabolite variation at plant flowering stage. Among Thai varieties, net photosynthetic rate (Pn) was significantly highest in varieties OC059 and OC081. The greatest growth and biomass measures were observed in OC064. Antioxidant capacity also varied, with the greatest accumulation of total phenolic compounds (TPC), flavonoids, and antioxidant activity by DPPH assay in OC064, and highest terpenoid content in OC194. The accumulation of major compounds confirmed by showing the highest levels of eugenol in OC057, OC063, OC194, and OC195 and methyl eugenol in OC072 and OC081. The highest α-humulene content was found in OC059. PCA based on physiological responses and secondary metabolites indicate that OC064 was clearly distinguished from other cultivars/accessions. These findings demonstrate variation across holy basil accessions for physiologic responses, antioxidant capacity, and secondary compounds in PFAL. These insights lead to identification of suitable varieties which is the most important step of developing an efficient method for producing high quality raw materials of Thai holy basil for supplying the foods and pharmaceutical industries.

Basil (Ocimum basilicum L.) Leaves as a Source of Bioactive Compounds

Basil (Ocimum basilicum L.) is an annual spicy plant generally utilized as a flavouring agent for food. Basil leaves also have pharmaceutical properties due to the presence of polyphenols, phenolic acids, and flavonoids. In this work, carbon dioxide was employed to extract bioactive compounds from basil leaves. Extraction with supercritical CO2 (p = 30 MPa; T = 50 °C) for 2 h using 10% ethanol as a cosolvent was the most efficient method, with a yield similar to that of the control (100% ethanol) and was applied to two basil cultivars: “Italiano Classico” and “Genovese”. Antioxidant activity, phenolic acid content, and volatile organic compounds were determined in the extracts obtained by this method. In both cultivars, the supercritical CO2 extracts showed antiradical activity (ABTS●+ assay), caffeic acid (1.69–1.92 mg/g), linalool (35–27%), and bergamotene (11–14%) contents significantly higher than those of the control. The polyphenol content and antiradical activity measured by the three assays were higher in the “Genovese” cultivar than in the “Italiano Classico” cultivar, while the linalool content was higher (35.08%) in the “Italiano Classico” cultivar. Supercritical CO2 not only allowed us to obtain extracts rich in bioactive compounds in an environmentally friendly way but also reduced ethanol consumption.

Influence of Nitrogen Fertilizer on the Antioxidative Potential of Basil Varieties (Ocimum basilicum L.).

Total phenolic content (TPC) in extracts of basil depended on the cultivar and type of fertilization used in cultivation. TPC was determined spectrophotometrically with the Folin–Ciocalteu reagent. The antioxidant activity of extracts was analyzed by scavenging of DPPH and ABTS radicals, on the basis of metal chelating ability (MetChel) and ferric reducing antioxidant power (FRAP). The greatest TPC was determined in the purple cultivars—141.35 and 165.44 mg gallic acid/g d.m. for fertilized with ammonium nitrate (NH4NO3) and ammonium sulfate ((NH4)2SO4), respectively. Their extracts had the greatest antioxidant capacity in the majority of the methods used. The results varied depending on the modelling system used. The amount of polyphenols in individual basil cultivars differed significantly (p < 0.05) depending on the fertilization used in the culture. Regarding TPC, DPPH, ABTS, FRAP, and MetChel variables, we observed a significant effect for the applied cultivation. In the case of MetChel factor, lower results of all investigated basil species were observed for cultivation with ammonium sulfate. PCA demonstrated in the present study shows that Sweet and Cinnamon Basil samples cultivated with ammonium nitrate create a separated group. We recommend cultivation with ammonium sulfate fertilizers for these varieties of basil. The high content of phenolic compounds demonstrated in Sweet and Cinnamon Basil cultivated with ammonium sulfate, and thus associated antioxidant activity, indicates that it can constitute a valuable source for bioactive compounds in a balanced diet.

Effect of Self- and Inter-Cultivar Grafting on Growth and Nutrient Content in Sweet Basil (Ocimum basilicum L.).

Vegetable grafting has been applied to fruiting crops, yet only to a limited extent in leafy greens and herbs which may also benefit from grafting. In this study, we examined the effect of reciprocal grafting two sweet basil (Ocimum basilicum L.) cultivars of differing vigor on plant growth and leaf mineral nutrient concentration to test whether differences in growth exist due to grafting and whether such differences are due to altered plant nutrient status in two trials. Two cultivars ‘Nufar’ (NU), a high vigor cultivar, and ‘Dolce Fresca’ (DF), a cultivar developed for compact growth, were selected. Four grafted treatments (scion/rootstock) were created by self-grafting (NU/NU and DF/DF) and reciprocal inter-cultivar grafting (DF/NU and NU/DF). Un-grafted plants (ug-NU and ug-DF) served as controls. Following grafting, plants were grown for 26 or 21 days in a greenhouse. DF rootstocks decreased NU shoot dry mass (19–29%) and stem length (12%) compared to ug-NU in both trials, while dry root mass was reduced (28%) in the second trial. In contrast, NU rootstocks did not affect DF growth in the first trial but significantly decreased dry shoot (18%) and root (31%) mass, compared to ug-DF in the second. Concentration of most inorganic nutrients examined was affected by both rootstock and scion genotype. For NU scions, DF rootstocks resulted in significantly higher (5–29%) levels of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, copper, and zinc in leaf tissue than ug-NU. For DF scions, NU rootstocks resulted in significantly higher (7–9%) levels of potassium and phosphorus but significantly lower (11–23%) levels of magnesium, sulfur, boron, copper, and zinc when compared to ug-DF. Results of this study show that inter-cultivar grafting sweet basil using a more vigorous cultivar as a rootstock did not enhance the growth of a less vigorous scion and reduced concentrations of certain nutrients. However, grafting a vigorous scion to a less vigorous rootstock reduced shoot growth but generally increased nutrient concentrations. This suggests that changes in growth in grafted basil are not due to altered nutrient status. Further research is needed to determine specific physiological processes influencing grafted basil growth.

Estimation of Morphological Features and Essential Oil Content of Basils (Ocimum basilicum L.) Grown under Different Conditions.

This study was carried out in the experimental field and in unheated greenhouses of the Lithuanian Research Centre for Agriculture and Forestry Institute of Horticulture. The investigation aimed to evaluate the morphological features, amount of essential oil, and productivity of 10 basil (Ocimum basilicum L.) cultivars grown under different growing conditions. Studied cultivars were different according to morphological parameters, productivity, and the accumulation of essential oil. Most of the investigated parameters were influenced by growing conditions. Basil plants of cultivars Sweet Genovese and Toscano were determined to be the highest, and their height reached up to 70.5 cm. Cultivar Sweet Genovese was the most productive; its fresh herb mass per plant reached up to 0.71 kg under growing in the open field and greenhouse. Higher air temperature and constant watering of the soil in the greenhouse increased the accumulation of essential oils of basil. The biochemical analyses showed that the essential oil amount of 31% was higher when basils were grown in a greenhouse compared to an open field.

Zinc and methyl jasmonate modulate the growth and the volatile compounds of the 'Albahaca Dante' basil cultivated in vitro

The species Ocimum basilicum has many cultivars with different chemotypes. The basil cultivar ‘Albahaca Dante’ has great economic potential. Nevertheless, there is little data about the production of volatiles and the growth using elicitors. This study aims to evaluate growth, physiological disorders, enzymatic activity, biochemistry, stomatal analysis, and the volatile compounds of Ocimum basilicum L.' Albahaca Dante' cultivated in vitro under different concentrations of zinc sulfate (ZnSO4) and methyl jasmonate (MeJa). The experiment was conducted in a completely randomized design (CRD). Five treatments were evaluated based on the combination of MeJa x Zinc Sulfate, using a Murashige and Skoog medium. The results demonstrate that MeJa reduced the formation of abnormal seedlings. Nevertheless, the growth and the number of leaves were not incremented compared in half without elicitors. The number of volatile compounds was lower in the treatment without elicitors and with 25µM ZnSO4 + 1µMMeja. Methyl chavicol was the main compound in both treatments. In this case, the seedlings had smaller stomata with higher density. The seedlings that were developed under unfavorable conditions (75µM ZnSO4 + 1µM MeJa and 75µM ZnSO4 + 5µM MeJa) produced compounds such as Eugenol, Linalool, Methyleugenol, α-Bergamotene, and showed a reduction in the stomatal density, but larger size. The elicitors influenced the activity of antioxidant enzymes, except for 75µM ZnSO4 + 1µM MeJa, which occasioned an acute decrease of all enzymes. The elicitors altered the volatile composition of this basil cultivar and its biochemical responses

IN VITRO CULTURE AND ANTIMICROBIAL ACTIVITY OF Ocimum basilicum L. var. ʻSpicy globeʼ AND Artemisia eriantha Ten.

In this preliminary screening, we assessed the antibacterial activity of in vitro obtained plant material, namely shoots of Artemisia eriantha (Asteraceae) and callus of Ocimum basilicum L. var. ʻSpicy globeʼ, against two bacteria strains, the Gram-positive ones including Staphylococcus aureus ATCC 25923, and Gram-negative, Escherichia coli ATCC 25922 by the plate-counting method. Artemisia sprouted on the Murashige-Skoog medium added with 1.5 mg/L benzylaminopurine and ʻSpicy globeʼ basil developed callus on Murashige - Skook basal medium supplemented with 2.5 mg/L naphtylacetic acid (NAA). The method of using small pieces of vegetal material inoculated in Erlenmeyer flasks on liquid Luria-Bertani medium added with standardized microbial cell suspension was not effective against the pathogenic bacteria in the case of the Artemisia species, but the same method was efficient for basil cultivar ʻSpicy globeʼ.

Foliar Spraying with Potassium Bicarbonate Reduces the Negative Impact of Drought Stress on Sweet Basil (Ocimum basilicum L.).

In recent years, special attention has been paid to climate change assessment and research into our changing environment. The greatest economic losses worldwide are due to the negative effects of drought stress and extreme temperature on the plants’ morphological, physiological, and biochemical properties which limit crop growth and productivity. Sweet basil (Ocimum basilicum L.) is one of the most popular plants widely grown around the world as a spice, as well a medicinal, aromatic plant. The seedlings with 5–6 true leaves were divided into two groups, and one group of seedlings was sprayed with 10 mM potassium bicarbonate (KHCO3). Three days after potassium bicarbonate treatment, half of the plants from each group were subjected to a water deficit (drought stress), and the other half were grown under stress-free conditions (well-watered). The present study aimed to evaluate the effect of potassium bicarbonate (KHCO3) on morphophysiological parameters, phenolics content and the antioxidant activity of basil under drought conditions. The application of potassium bicarbonate to drought stressed plants significantly increased the chlorophyll content, fresh and dry weight, phenolics content in the two of tested cultivars, and antioxidant activity, determined by DPPH and ABTS methods. Principal component analysis showed that the first factor was highly and positively related to all the investigated parameters. Hierarchical clustering analysis showed that the first cluster was formed by being well-watered, well-watered and sprayed with potassium bicarbonate, and grown under drought conditions and sprayed with potassium bicarbonate basil cultivars, while the second cluster was formed by all the tested cultivars grown under drought conditions.