Next Article in Journal
Integrative Physiological, Transcriptome, and Proteome Analyses Provide Insights into the Photosynthetic Changes in Maize in a Maize–Peanut Intercropping System
Previous Article in Journal
Effect of Shading on Physiological Attributes and Proteomic Analysis of Tea during Low Temperatures
Previous Article in Special Issue
LC-ESI QToF MS Non-Targeted Screening of Latex Extracts of Euphorbia seguieriana ssp. seguieriana Necker and Euphorbia cyparissias and Determination of Their Potential Anticancer Activity
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Plants
Volume 13
Issue 1
10.3390/plants13010064
plants-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Phenotypic Variations and Bioactive Constituents among Selected Ocimum Species

by
Sintayehu Musie Mulugeta
*,
Zsuzsanna Pluhár
and
Péter Radácsi
Department of Medicinal and Aromatic Plants, Institute of Horticultural Sciences, Hungarian University of Agriculture and Life Sciences, Villányi út 29-43, H-1118 Budapest, Hungary
*
Author to whom correspondence should be addressed.
Plants 2024, 13(1), 64; https://doi.org/10.3390/plants13010064
Submission received: 28 November 2023 / Revised: 20 December 2023 / Accepted: 21 December 2023 / Published: 24 December 2023
(This article belongs to the Special Issue New Insights in the Research of Bioactive Compounds from Plant Origin with Nutraceutical and Pharmaceutical Potential II)
Browse Figures
Review Reports Versions Notes

Abstract

:
Basil (Ocimum species) represents an extraordinary group of aromatic plants that have gained considerable economic importance, primarily due to their essential oils, which have applications in medicine, culinary, and perfumery. The Ocimum genus encompasses more than 60 species of herbs and shrubs originally native to tropical regions. This genus stands out for its remarkable diversity, displaying a wide spectrum of variations in phenotype, chemical composition, and genetic makeup. In addition to genetic factors, the growth, development, and essential oil production of basil are also influenced by environmental conditions, ontogeny, and various other factors. Consequently, the primary objective of this study was to explore the diversity in both the morphological characteristics and essential oil composition among basil genotypes preserved within the gene bank of the Hungarian University of Agriculture and Life Sciences’ Department of Medicinal and Aromatic Plants. The investigation involved the assessment of fifteen basil genotypes, representing four distinct species: Ocimum basilicum (including ‘Anise’, ‘Clove’, ‘Fino Verde’, ‘Licorice’, ‘Mammoth’, ‘Mrs. Burns’, ‘Thai tömzsi’, ‘Thai hosszú’, and ‘Vietnamese basil’), Ocimum sanctum (green holy basils), Ocimum citrodora (Lemon basil), and Ocimum gratissimum (African and Vana holy basil). The genotypes exhibited significant variations in their morphological growth, essential oil content (EOC), and composition. African basil produced more biomass (408.3 g/plant) and showed robust growth. The sweet basil cultivars clove, licorice, Thai tömzsi, and Thai hosszú also exhibited similar robust growth trends. Vietnamese basil, on the other hand, displayed the lowest fresh biomass of 82.0 g per plant. Both holy basils showed EOC levels below 0.5%, while Mrihani basil stood out with the highest EOC of 1.7%. The predominant constituents of the essential oil among these genotypes comprised estragole, thymol, methyl cinnamate, linalool, and eugenol. In conclusion, this study showed that the genotypes of basil stored in the department’s gene bank exhibit a wide range of variability, both within and between species.

1. Introduction

The genus Ocimum L. belongs to the Lamiaceae family and is commonly referred to as basil. The name “basil” originates from the Greek word “basilikos”, which translates to “royal”. Ocimum species encompass a variety of annual and perennial herbs and shrubs. These plants are distributed across different geographical regions, with three primary areas of Ocimum diversity identified: (a) the tropical and subtropical regions of Africa; (b) the tropical parts of Asia; and (c) the tropical areas of America, particularly in Brazil. However, basil is extensively cultivated worldwide [1]. The genus presents extensive morphological diversity, encompassing approximately 65 species due to widespread cultivation and the ease of cross-pollination. This has led to the emergence of numerous subspecies, varieties, and forms [2,3,4]. Among the most well-known species renowned for their strong aromatic properties are Ocimum basilicum, Ocimum gratissimum, Ocimum sanctum, and Ocimum americanum. In addition to these species, there are several varieties and related species, or hybrids [3,4]. The genus is recognized for its polymorphism, extensive chemical diversity [5], which varies in both volatile and non-volatile compounds [6,7,8], and a significant level of genetic variability [9,10]. Morphologically, basil can be identified by its square stems, leaves positioned opposite each other on the stem, and the presence of brown or black seeds, known as nutlets, along with flower spikes. Nevertheless, the characteristics of basil leaves and flowers, such as their color, size, shape, and texture, exhibit variations among different species. The leaves exhibit diverse textures, ranging from smooth and glossy to curled and covered in fine hairs. Additionally, basil plants can display a range of leaf colors, from green to shades of blue and purple. Furthermore, the height and canopy spread of basil plants can differ based on their specific species [1,5,11]. On the other hand, the essential oil content varies between 0.2% and 5.22%, primarily influenced by factors such as the plant species, its origin, and its phenological stage [2,12]. Researchers worldwide have extensively examined the chemical compositions of basil essential oil, resulting in the identification of approximately 140 constituents. These components include monoterpenes, sesquiterpenes, carboxylic acids, aliphatic aldehydes, aliphatic alcohols, aromatic compounds, and other miscellaneous compounds [2,13,14]. Among the primary monoterpene derivatives are linalool, camphor, 1,8-cineole, thymol, citral, and geraniol. In contrast, other members of the same genus typically possess essential oils characterized by significant quantities of phenolic derivatives such as eugenol, methyl eugenol, methyl chavicol (estragole), and methyl cinnamate, often accompanied by varying levels of linalool [2,14,15]. Apart from volatile essential oils, basil herbs are also rich in polyphenols ranging from phenolic acids (rosmarinic acid, caffeic acid, caftaric acid, chicoric acid, and others), simple or complex flavonoids, and colored anthocyanins [16,17,18]. The aromatic essential oils and the polyphenols of basil species are used in the flavor, fragrance, cosmetics, aromatherapy, and pharmaceutical industries [13,19]. They exhibit antioxidant, anti-inflammatory, antimicrobial, and immunomodulatory activities [20,21,22]. In addition, the essential oils have demonstrated insecticidal and repellent properties, making them useful in pest control [23,24,25]. The morphological development, essential oil content, and composition of Ocimum species are significantly influenced by genetic factors, growing conditions, phenology, and other elements [26,27,28]. Consequently, this study aims to explore the variations in both the phenotypic morphological characteristics and essential oil composition among 15 basil genotypes cultivated in Budapest, Hungary, in 2022.

2. Results

2.1. Morphological Variability

The 15 different Ocimum genotypes displayed significant morphological differences, as indicated in Table 1 and Table 2 (p < 0.01). These variations were observed across a range of morphological characteristics, including plant height, canopy diameter, leaf size and weight, inflorescence length and number, and biomass production (both fresh and dry). In terms of height, Ocimum species ranged from low-growing plants of ‘Fino Verde’, which had a height of 23.0 cm, to taller plants of ‘African basil’ reaching 56.3 cm in height. Sweet basil cultivars such as ‘Fahéj illatú’, ‘Licorice’, ‘Thai tömzsi’, and ‘Thai hosszú’ also had over 50.0 cm taller plants. The canopy morphology also varies greatly, with some species having dense and bushy canopies, such as ‘Vana holy basil’ (27.2 cm) and ‘Fino Verde’ (32.5 cm), and others having more open and spreading canopies, such as ‘Anise’, ‘Clove’, ‘Licorice’, and ‘Thai hosszú’, which had over 50.5 cm spread. Furthermore, leaf morphology shows significant diversity among the Ocimum genotypes. The sweet basil cultivar ‘Mammoth’ stands out with its exceptionally long leaves, measuring 12.4 cm in length and 8.6 cm in width, with a larger area of 52.0 cm2 per leaf and weighing 214.0 g per 100 leaves. African basil exhibited the second largest leaves, measuring 10.3 cm in length and 6.9 cm in width, covering an area of 36.8 cm2 per leaf, and weighing 148 g per 100 leaves. In contrast, ‘Fino Verde’ exhibits smaller leaf growth, with leaves that are 1.8 cm longer and 0.9 cm wider, covering an area of 1.4 cm2 per leaf, and weighing 3.5 g less per 100 leaves. The remaining genotypes fall within these ranges.
Inflorescence is another trait that varies among Ocimum species. Fahéj illatú, ‘Licorice’, ‘Mrs. Burns’, and ‘Thai hosszú’ displayed inflorescence lengths exceeding 25 cm. In contrast, ‘Fino Verde’ had the shortest inflorescences, measuring only 6.5 cm, but it had the highest inflorescence count (152.7). Variability in biomass production was noticeable among the different genotypes, resulting in a range of growth and yield outcomes (see Table 1 and Table 2). In line with that, sweet basil cultivars such as ‘Clove’, ‘Mammoth’, and ‘Thai tömzsi’, as well as ‘African basil’, yielded over 395 g/plant of fresh herb yield and 80 g/plant of dry herb yield per plant. In contrast, ‘Vietnamese basil’ and ‘Vana holy basil’ produced significantly lower yields, with less than 100 g of fresh herb yield and 25 g of dry herb yield per plant.
Furthermore, through hierarchical cluster analysis, we were able to identify four distinct morphological categories, as depicted in Figure 1. The initial cluster consisted of five basil genotypes, namely ‘Anise’, ‘Mrihani’, ‘Fino Verde’, ‘Lemon’, and ‘green holy basil’. The second cluster included ‘Mrs. Burns’, ‘Vietnamese’, and ‘Vana holy basil’ cultivars. The third cluster featured sweet basil cultivars, including ‘Clove’, ‘Thai tömzsi’, ‘Fahéj illatú’, ‘Thai hosszú’, and ‘Licorice’, while the final cluster was exclusively composed of ‘Mammoth’ and ‘African basil’ cultivars. In addition, principal component analysis (PCA) revealed relationships between genotypes and quantitative morphological traits (see Figure 2). These two principal components collectively explained 68.99% of the variance, with PC1 accounting for 43.60% and PC2 for 25.39%.

2.2. Chemical Attributes of Ocimum Species

2.2.1. Essential Oil Content and Essential Oil Yield

This research finding revealed a significant difference (p < 0.01) among the genotypes in terms of essential oil production, as presented in Figure 3. The essential oil content (EOC) among the genotypes ranged between 0.4% and 1.7%. The highest EOC was observed in the sweet basil cultivar ‘Mrihani’, followed by ‘Fino Verde’ (1.5%) and ‘African basil’ (1.5%). In contrast, both holy basil genotypes (‘green holy basil’ and ‘Vana holy basil’) had <0.5% essential oil. Clove and ‘African basil’ had the highest EOY (≥1.2 mL/plant). In contrast, ‘Vana holy basil’ had the lowest EOY (0.1 mL/plant).

2.2.2. Essential Oil Composition

The essential oil composition among the 15 basil cultivars exhibited remarkable variation, characterized by a predominant presence of either a single compound or a combination of multiple compounds (see Table 3 and Table 4). Over 50 compounds have been identified in each sweet basil (Ocimum basilicum) cultivar. Estragole, for instance, was found in higher proportions, exceeding 60%, in the essential oils of ‘Clove’, ‘Mrihani’, ‘Thai hosszú’, ‘Thai tömzsi’, and ‘Vietnamese basil’. However, other sweet basil cultivars showed a mixture of multiple compounds with different ratios. Consequently, ‘Anise’ basil, ‘Fahéj illatú’, and ‘Licorice’ basil exhibited higher ratios of (E)-methyl cinnamate and linalool, with percentages of 28.7/12.2%, 34.8/28.1%, and 42.7/19.3%, respectively. Additionally, ‘Anise’ basil also had a significant ratio of estragole (25.1%). Notably, ‘Fino Verde’ and ‘Mammoth’ basil predominantly contained linalool, exceeding 30% in their essential oil composition. The volatile oil of ‘Mrs. Burns’ basil, on the other hand, displayed a composition comprising estragole (21.9%), linalool (19.5%), and citral (12.6%). In addition, more than 60 compounds were detected in both holy basil cultivars. In ‘green holy basil’ of Ethiopian origin, the main essential oil components included β-bisabolene (14.1%), linalool (12.1%), estragole (10.1%), and eugenol (7%). However, ‘Vana holy basil’ essential oil was characterized by higher levels of eugenol (27.3%), caryophyllene oxide (14.4%), and (E)- β-Caryophyllene (6.8%). The ‘Lemon’ basil essential oil was found to contain 55 different compounds, with estragole making up 61.4% and citral, comprising neral and geranial, accounting for 13.9% of the composition. Meanwhile, ‘African basil’ was found to contain 39 different compounds, with higher proportions of monoterpenes, including 20.7% p-Cymene and 10.6% γ-terpinene, as well as a significant presence of phenylpropanoids, accounting for 42.1% thymol.
Furthermore, the hierarchical cluster analysis based on the composition of essential oils revealed the presence of four distinct groups (Figure 4). In the first cluster, ‘Anise’, ‘Fahéji illatu’, and ‘Licorice’ basil were grouped due to their higher levels of (E)-methyl cinnamate (>28%) and linalool (>12%). In the second cluster, there was a mixture of components with varying ratios. For instance, ‘Fino Verde’ and ‘Mammoth’ basil displayed linalool ratios exceeding 32.7%. Conversely, ‘Thai tömzsi’ and ‘Mrs. Burns’ basil contained higher levels of estragole (>21%) and linalool (19%). Vana holy basil exhibited significant proportions of eugenol (27.3%) and caryophyllene oxide (14.4%) in the second cluster. The ‘African basil’ was categorized in the third cluster, characterized by a higher ratio of thymol (42.1%) and p-cymene (20.7%). The fourth cluster encompassed ‘Clove’, ‘Thai hosszú’, ‘Vietnamese’, ‘Mrihani’, and ‘lemon’ basils, all of which contained over 60% estragole. As indicated in Figure 5, the PCA further provides insight into the relationship between genotypes and essential oil components. The two principal components explained 47.38% of the variance, PC1 explaining 26.80% and PC2 explaining 20.58%.

3. Discussion

The Ocimum genus represents a notably diverse and valuable medicinal plant, characterized by significant genetic variation, differing morphological traits [29,30], as well as variations in the content and composition of essential oils [29,31,32]. These aromatic essential oils and the nonvolatile compounds found in basil species are used in flavoring, fragrance, cosmetics, aromatherapy, and pharmaceuticals. They are highly regarded for their diverse biological properties, including antimicrobial activity, insecticidal effects, antioxidant capabilities, and numerous therapeutic benefits [13,19,22,24]. Nevertheless, it is important to note that the production, accumulation, and distribution of secondary metabolites are significantly influenced by genetic factors, developmental stages, morphogenetic processes, environmental conditions, and processing techniques [26,27,28]. Accordingly, the morphological traits, essential oil production, and composition of 15 distinct Ocimum genotypes belonging to four distinct species of Ocimum were evaluated and discussed below. There is considerable variation in morphology among Ocimum species, encompassing both vegetative and reproductive growth characteristics. Among these genotypes, African basil exhibits robust growth, with taller plants, broader canopy spreads, and greater biomass production. Comparable growth and yield were also recorded from ‘Clove’, ‘Licorice’, ‘Thai tömzsi’, and ‘Thai hosszú’. In terms of leaf size and weight, ‘Mammoth’ basil exhibits the largest. In contrast, ‘Fino Verde’ basil plants were dwarf types, which were short and small-leafed. Although they have smaller leaves and lower herb yields, they produce the highest number of inflorescences. Earlier studies have demonstrated a significant morphological diversity within Ocimum species, a result of factors such as polyploidy, aneuploidy, inter- and intra-specific hybridizations, as well as cultivation and breeding practices [10,29,33,34,35]. As a polymorphic species, Ocimum gratissimum exhibits a broader range of morpho-chemical traits, including plant height and fresh herb yield spanning from 46 to 123 cm and 98 to 618.3 g/plant, respectively [5,36,37,38,39], consistent with our own findings. In the case of Ocimum basilicum cultivars, previous research has shown variability in height (29.2 to 100 cm), canopy diameter (24.9 to 97.7 cm), and fresh yield (140 to 634 g/plant), influenced by factors such as growing conditions, cultivation seasons, geographical location, and specific cultivars [5,29,30,37,40]. Notably, ‘Fino Verde’ of O. basilicum exhibited a height of over 60 cm and a fresh herb yield exceeding 550 g/plant, contrasting with our findings [40]. Furthermore, green holy basil hand height varies from 37.3 to 71.9 cm with a canopy spread of 50 to 67.3 cm [41]. Despite differences in cultivation practices and microclimates, green holy basil is reported to produce between 110 and 361.36 g/plant of fresh biomass [5,39].
The observed variability in essential oil content (EOC) was significant. The ‘Mrihani’ basil exhibited the highest EOC at 1.7%, followed by ‘Fino Verde’ and the African basil varieties. Conversely, ‘Mrs. Burns’, ‘green holy basil’, and ‘Vana holy basil’ displayed the lowest EOC, measuring less than 0.7%. Previous research has suggested that, aside from genetic factors, essential oil content and composition ratios are significantly influenced by growing conditions, growth stage, and processing methods. For instance, EOC in sweet basil cultivars has been reported to range from 0.11% to 3.4% in various studies [42,43,44]. Specifically, ‘Fino Verde’s’ essential oil content has been documented to range from 0.5% to 3.4% in different studies [12,40,45]. In contrast to our findings, the EOC of Anise basil fluctuates between 0.62% and 2.67%, depending on the season and geographical region [12,46]. Similarly, green holy basil was reported to have 0.43% EO [47]. Consistent with our results, previous studies have reported varying essential oil content (EOC) for O. gratissimum, ranging from 0.11% to 1.5%. This variability is attributed to factors such as different chemotypes, production seasons, plant parts used, and cultivation regions, which were documented [12,38,48,49]. A vast variety of aromatic compounds are present in the essential oil of basil species, which is recognized for its intricate complexity. The Ocimum species of basil include a large number of cultivars and chemotypes, each of which has a distinctive profile of volatile oils. Based on previous studies [27,50,51], this composition can exhibit significant variations due to factors like geographic location, environmental conditions, cultivation techniques, the state of the plant material (fresh or dry), and genetic diversity. Additionally, processes like hybridization that occur both within and between species through cross-pollination, as well as natural evolutionary events, polyploidy, and selective breeding, have all significantly influenced chemical diversification among diverse Ocimum species. These phenomena have been documented in various studies [9,14,52]. In line with that, Ocimum basilicum has been categorized into four primary chemotypes based on the composition of its essential oils, as outlined by Lawrence et al. [50]. These chemotypes include methyl chavicol (estragole), linalool, methyl eugenol, and methyl cinnamate, with each of them further exhibiting several subgroups. Our observations identified the presence of estragole, methyl cinnamate, linalool, and their combinations in sweet basil cultivars. Our finding further corresponds with the findings of Zeljković et al. [44], who reported substantial levels of linalool (>55%) in Italian (Fino Verde Compatto) and Mammoth basil. It was also documented that linalool (27%) and 1,8-cineole (13%) are the primary compounds in Fino Verde essential oil [45]. Furthermore, Carovic’-Stanko et al. [11] reported Thai basil accessions that were rich in estragole (78.2%) and linalool (46.16%). Earlier research findings have indicated that Anise basil displays a wide range of chemical profiles, with methyl chavicol ranging from 12% to 82.2% and linalool within a range of 30% to 56% [12,42,53]. Additionally, Thai basil has been reported to contain significant amounts of methyl chavicol (20% to 90%) and linalool (>20%) [12,53]. In agreement with our findings, Vieira and Simon [7] and Couto et al. [53] also observed that Mrs. Burns basil oil predominantly consists of linalool (38.3% to 46.1%) and citral (16.6% to 49.56%). Conversely, the composition of other species was characterized by the presence of multiple components. Hence, green holy basil predominantly consists of bisabolene, linalool, estragole, and eugenol. Lemon basil, on the other hand, is primarily composed of estragole and citral. A chemotype of lemon basil from New Guinea was identified, primarily composed of methyl chavicol (estragole) but devoid of citral [7]. Additionally, they noted the existence of two lemon basil accessions with higher citral ratios. Another study highlighted that the principal components of Lemon basil (O. citriodorum) volatile oil were estragole and citral [54]. Regarding the chemotaxonomy of O. gratissimum, six chemotypes have been reported, including thymol, eugenol, citral, methyl cinnamate, linalool, and geraniol. Consequently, the two O. gratissimum cultivars in our study, Vana holy basil, and African basil, belong to the eugenol and thymol chemotypes, respectively. In line with our findings, various authors have also documented that eugenol constitutes the predominant volatile oil compound in Vana holy basil, accounting for more than 50% of the total composition [38,48,54]. Furthermore, thymol and cymene were also reported as primary components in the volatile oil of African basil cultivars [11,55,56].

4. Materials and Methods

4.1. Experimental Site Description

The experiment was conducted in 2022 at the Hungarian University of Agriculture and Life Sciences (MATE) experimental field in Budapest-Soroksár. During the investigation, an average air temperature of 15 °C and a rainfall of 234 mm were recorded. Figure 6 illustrates the daily weather conditions, including rainfall and air temperature. Furthermore, Table 5 shows the soil macronutrient and micronutrient concentrations. It had high concentrations of phosphorus (544.43 mg/kg), potassium (177.36 mg/kg), and significant amounts of micronutrients.

4.2. Plant Material and Growing Conditions

In this study, we examined 15 distinct basil genotypes, representing four different Ocimum species (Figure 7). Among these, eleven genotypes belonged to Ocimum basilicum cultivars, two were cultivars of Ocimum gratissimum, and the remaining two belonged to Ocimum citrodora and Ocimum sanctum. The seeds for this experiment were sourced from the Medicinal and Aromatic Plants Department gene bank (MATE), as detailed in Table 6. The germination process involved sowing the seeds in seed trays measuring 27 × 57 cm within a greenhouse during the second week of March. Once healthy seedlings had grown two leaves each, they were transplanted into an open field with a spacing of 40 cm × 40 cm, arranged in 4 rows with 6 plants per row. To ensure scientific rigor, these plantings were replicated three times, following a randomized complete block design (RCBD) arrangement. Throughout the cultivation period, we maintained a watering schedule of three times per week and performed weekly cultivation activities, all without the use of chemical fertilizers or protective chemicals. Harvesting was conducted 10 days after full bloom, and subsequently, fresh herb samples underwent a two-week drying process in a well-ventilated room.
Quantitative phenotypic traits: Eleven morphological features were quantified for characterization. The plant heights (in cm), canopy diameters (in cm), and fresh herb weights (in g/plant) of ten plants were measured during harvest. After allowing the herbs to dry naturally in a well-ventilated room, we recorded their dried weights (in g/plant). For leaf metrics such as leaf length, width, and area, we took the mean of 20 leaves per genotype and two leaves per sample plant from the upper third internode. After acquiring the images of the leaves, image analysis software (ImageJ (version 1.54h), National Institutes of Health, Bethesda, MD, USA) was used to determine the leaf area (in cm2/leaf). Ten plants per genotype and three inflorescences per genotype were counted and measured to determine the number of inflorescences and their lengths (cm). Upon adequate seed extraction and drying, 1000 seeds of each genotype were weighed.
Essential oil content determination: For each treatment, we harvested a total of ten plant samples, which were subsequently dried for two weeks in well-ventilated rooms. After drying, we gathered bulk samples made up of dried leaves and inflorescences (without stems) to measure the amount of essential oils present. Each time, we used 20 g of the dried material from the samples and hydro-distilled it for two hours in a Clevenger-style device with 500 mL of distilled water. This procedure followed the recommendations given in the VII Hungarian Pharmacopoeia [57]. After carefully removing any traces of water that remained in the essential oils, the samples were placed in a sealed vial and kept in a refrigerator set to 4 °C for one day.
Essential oil composition analysis: We employed the gas chromatography-mass spectrometry (GC-MS) method to analyze the composition of the essential oil. The GC analysis was carried out using an Agilent Technologies 6890 N instrument (Agilent Technologies, Inc., Santa Clara, CA, USA), equipped with an HP-5MS capillary column measuring 30 m in length, 0.25 mm in diameter, and featuring a 0.25 μm film thickness. The instrument followed a temperature program that began at an initial temperature of 60 °C with a gradual heating rate of 3 °C per minute until reaching 240 °C, which was maintained for 5 min. The injector and detector temperatures were set at 250 °C. Helium served as the carrier gas, flowing at a constant rate of 1 mL per minute with a split ratio of 30:1 and an injection volume of 0.2 μL (diluted to 1% in n-hexane). The individual compound proportions were expressed as percentages of the total area. The same equipment was utilized for component identification, employing an Agilent Technologies MS 5975 detector (Agilent Technologies, Inc., Santa Clara, CA, USA). The ionization energy was set at 70 eV, and the mass spectra were recorded in full scan mode, generating total ion current (TIC) chromatograms. To calculate linear retention indices (LRI), a mixture of aliphatic hydrocarbons (C9-C23) in n-hexane was injected, applying the generalized equation proposed by Van Den Dool and Kratz [58]. The LRI values and mass spectra were cross-referenced with commercial databases (NIST, Wiley, Hoboken, NJ, USA), Adams [59], and a homemade library mass spectra were built up from data that were obtained from standard (Sigma/Aldrich, St. Louis, MO, USA) pure compounds. The GC samples underwent three repetitions for accuracy.
Data analysis: The morphological and essential oil data of the genotypes were evaluated through a one-way analysis of variance (ANOVA). Before conducting the ANOVA, the data’s normal distribution and homogeneity of variances were verified using Shapiro–Wilk and Levene’s tests, respectively. Significant differences in means were investigated using Tukey’s post hoc test at a significance level of p < 0.05. Furthermore, a hierarchical cluster analysis was carried out utilizing the Ward method based on squared Euclidean distance, leading to the creation of a dendrogram. All statistical analyses were executed using IBM SPSS 29 software, while principal components analysis (PCA) and dendrogram generation were performed using Origin Pro 2023b software.

5. Conclusions

This research conclusion highlights the remarkable phenotypic and biochemical diversity observed within the fifteen basil genotypes preserved in the department’s gene bank. There is a wide range of diversity in morphological traits, essential oil production, and composition. Notably, certain genotypes, including African basil, Clove, Licorice, Thai tömzsi, and Thai hosszú, exhibited robust morphological growth. Comparatively, Mrihani, Fino Verde, and African basil varieties produced higher levels of essential oil. Moreover, the investigation revealed a wide range of intra- and inter-specific chemical diversity in the essential oil compositions of Ocimum taxa, including estragole, thymol, methyl cinnamate, linalool, eugenol, and various mixed compositions. This comprehensive analysis significantly contributes to our understanding of their inherent diversity in this growing region (Hungary).

Author Contributions

Conceptualization, S.M.M. and P.R.; methodology, S.M.M. and P.R.; software, S.M.M. and P.R.; validation, S.M.M., P.R. and Z.P.; formal analysis, S.M.M. and P.R.; investigation, S.M.M. and P.R.; resources, Z.P. and P.R.; data curation, S.M.M. and P.R.; writing—original draft preparation, S.M.M.; writing—review and editing, S.M.M., Z.P. and P.R.; visualization, S.M.M.; supervision, Z.P. and P.R. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

The data is contained within the manuscript.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Paton, A.; Harley, M.R.; Harley, M.M. Ocimum: An Overview of Classification and Relationships. In Basil: The Genus Ocimum; Hiltunen, R., Holm, Y., Eds.; Harwood Academic Publishers: Amsterdam, The Netherlands, 1999; pp. 1–38. [Google Scholar]
  2. Hiltunen, R.; Holm, Y. (Eds.) Essential oil of Ocimum. In Basil: The Genus Ocimum; Harwood Academic Publishers: Amsterdam, The Netherlands, 1999; pp. 77–111. [Google Scholar]
  3. Lal, R.K.; Gupta, P.; Chanotiya, C.S.; Sarkar, S. Traditional Plant Breeding in Ocimum. In The Ocimum Genome, Compendium of Plant Genomes; Shasany, A.K., Kole, C., Eds.; Springer: Cham, Switzerland, 2018; pp. 89–98. [Google Scholar]
  4. Maddi, R.; Amani, P.; Bhavitha, S.; Gayathri, T.; Lohitha, T. A review on Ocimum species: Ocimum americanum L., Ocimum basilicum L., Ocimum gratissimum L. and Ocimum tenuiflorum L. Int. J. Res. Ayurveda Pharm. 2019, 10, 41–48. [Google Scholar]
  5. Patel, R.P.; Singh, R.; Saikia, S.K.; Rajeswara Rao, B.R.; Sastry, K.P.; Zaim, M.; Lal, R.K. Phenotypic characterization and stability analysis for biomass and essential oil yields of fifteen genotypes of five Ocimum species. Ind. Crop. Prod. 2015, 77, 21–29. [Google Scholar] [CrossRef]
  6. Hasegawa, Y.; Tajima, K.; Toi, N.; Sugimura, Y. Characteristic components found in the essential oil of Ocimum basilicum L. Flav. Fragr. J. 1997, 12, 195–200. [Google Scholar] [CrossRef]
  7. Vieira, R.F.; Simon, J.E. Chemical characterization of basil (Ocimum spp.) based on volatile oils. Flavour Fragr. J. 2006, 21, 214–221. [Google Scholar] [CrossRef]
  8. Pyne, R.M.; Honig, J.A.; Vaiciunas, J.; Wyenandt, C.A.; Simon, J.E. Population structure, genetic diversity, and downy mildew resistance among Ocimum species germplasm. BMC Plant Bio. 2018, 18, 69. [Google Scholar] [CrossRef] [PubMed]
  9. Carovic’-Stanko, K.; Liber, Z.; Besendorfer, V.; Javornik, B.; Bohanec, B.; Kolak, I.; Satovic, Z. Genetic relations among basil taxa (Ocimum L.) based on molecular markers, nuclear DNA content, and chromosome number. Plant Syst. Evol. 2010, 285, 13–22. [Google Scholar] [CrossRef]
  10. Patel, R.P.; Kumar, R.R.; Singh, R.; Singh, R.R.; Rao, B.R.R.; Singh, V.R.; Lal, R.K. Study of genetic variability patterns and their possibility of exploitation in Ocimum germplasm. Ind. Crop. Prod. 2015, 66, 119–122. [Google Scholar] [CrossRef]
  11. Carović-Stanko, K.; Šalinović, A.; Grdiša, M.; Liber, Z.; Kolak, I.; Satovic, Z. Efficiency of morphological trait descriptors in discrimination of Ocimum basilicum L. accessions. Plant Biosys. Int. J. Deal. Asp. Plant Biol. 2011, 145, 298–305. [Google Scholar] [CrossRef]
  12. Simon, J.E.; Morales, M.R.; Phippen, W.B.; Vieira, R.F.; Hao, Z. Basil: A source of aroma compounds and a popular culinary and ornamental herb. In Perspectives on New Crops and New Uses; Janick, J., Ed.; ASHS Press: Alexandria, VA, USA, 1999; pp. 499–505. [Google Scholar]
  13. Pandey, A.K.; Singh, P.; Tripathi, N.N. Chemistry and bioactivities of essential oils of some Ocimum species: An overview. Asian Pac. J. Trop. Biomed. 2014, 4, 682–694. [Google Scholar] [CrossRef]
  14. Gurav, T.P.; Dholakia, B.B.; Giri, A.P. A glance at the chemodiversity of Ocimum species: Trends, implications, and strategies for the quality and yield improvement of essential oil. Phytochem. Rev. 2022, 21, 879–913. [Google Scholar] [CrossRef]
  15. Verma, R.S.; Padalia, R.C.; Chauhan, A.; Thul, S.T. Exploring compositional diversity in the essential oils of 34 Ocimum taxa from Indian flora. Ind. Crop. Prod. 2013, 45, 7–19. [Google Scholar] [CrossRef]
  16. Kwee, E.M.; Niemeyer, E.D. Variations in phenolic composition and antioxidant properties among 15 basil (Ocimum basilicum L.) cultivars. Food Chem. 2011, 128, 1044–1050. [Google Scholar] [CrossRef]
  17. Bajomo, E.M.; Aing, M.S.; Ford, L.S.; Niemeyer, E.D. Chemo-typing of commercially available basil (Ocimum basilicum L.) varieties: Cultivar and morphotype influence the phenolic acid composition and antioxidant properties. NFS J. 2022, 26, 1–9. [Google Scholar] [CrossRef]
  18. Beltrán-Noboa, A.; Jordan-Álvarez, A.; Guevara-Terán, M.; Gallo, B.; Berrueta, L.A.; Giampieri, F.; Battino, M.; Álvarez-Suarez, J.M.; Tejera, E. Exploring the chemistry of Ocimum species under specific extractions and chromatographic methods: A systematic review. ACS Omega 2023, 8, 10747–10756. [Google Scholar] [CrossRef] [PubMed]
  19. Li, Q.X.; Chang, C.L. Basil (Ocimum basilicum L.) oils. In Essential Oils in Food Preservation, Flavor, and Safety; Preedy, V.R., Ed.; Elsevier: Amsterdam, The Netherlands, 2016; pp. 231–238. [Google Scholar] [CrossRef]
  20. Pavithra, K.H.G.; Narase, G.P.N.; Prasad, M.P. Studies on antimicrobial activity of Ocimum species of Karnataka against clinical isolates. Ind. J. Pure App. Biosci. 2019, 7, 245–254. [Google Scholar] [CrossRef]
  21. Shahrajabian, M.H.; Sun, W.; Cheng, Q. Chemical components and pharmacological benefits of basil (Ocimum basilicum): A review. Int. J. Food Prop. 2020, 23, 1961–1970. [Google Scholar] [CrossRef]
  22. Anusmitha, K.M.; Aruna, M.; Job, J.T.; Narayanankutty, A.; Pb, B.; Rajagopal, R.; Alfarhan, A.; Barcelo, D. Phytochemical analysis, antioxidant, anti-inflammatory, anti-genotoxic, and anticancer activities of different Ocimum plant extracts prepared by ultrasound-assisted method. Physiol. Molec. Plant Pathol. 2022, 117, 101746. [Google Scholar] [CrossRef]
  23. Bhavya, M.L.; Chandu, A.G.S.; Devi, S.S. Ocimum tenuiflorum oil, a potential insecticide against rice weevil with anti-acetylcholinesterase activity. Ind. Crop. Prod. 2018, 126, 434–439. [Google Scholar] [CrossRef]
  24. Naveen, M.; Jayaraj, J.; Chinniah, C.; Mini, M.L.; Vellaikumar, S.; Shanthi, M. Insecticidal property of methanolic leaf extract of sweet basil, Ocimum basilicum (L.) against cigarette beetle, Lasioderma serricorne (Fab.) (Coleoptera: Anobiidae). J. Entomol. Zool. Stud. 2021, 9, 259–262. [Google Scholar] [CrossRef]
  25. Al-Harbi, N.A.; Al Attar, N.M.; Hikal, D.M.; Mohamed, S.E.; Abdel Latef, A.A.H.; Ibrahim, A.A.; Abdein, M.A. Evaluation of insecticidal effects of plants’ essential oils extracted from basil, black seeds, and lavender against Sitophilus oryzae. Plants 2021, 10, 829. [Google Scholar] [CrossRef]
  26. Paton, A.; Putievsky, E. Taxonomic problems and cytotaxonomic relationships between and within varieties of Ocimum basilicum and related species (Labiatae). Kew Bull. 1996, 51, 509–524. [Google Scholar] [CrossRef]
  27. Bernhardt, B.; Szabó, K.; Bernáth, J. Sources of variability in essential oil composition of Ocimum americanum and Ocimum tenuiflorum. Acta Aliment. 2015, 44, 111–118. [Google Scholar] [CrossRef]
  28. Mulugeta, S.M.; Sárosi, S.; Radácsi, P. Physio-morphological trait and bioactive constituents of Ocimum species under drought stress. Ind. Crop. Prod. 2023, 205, 117545. [Google Scholar] [CrossRef]
  29. Bernhardt, B.; Fazekas, G.; Ladányi, M.; Inotai, K.; Zámbori-Németh, É.; Bernáth, J.; Szabó, K. Morphological-, chemical- and RAPD-PCR evaluation of eight different Ocimum basilicum L. gene bank accessions. J. Appl. Res. Med. Arom. Plants 2014, 1, e23–e29. [Google Scholar] [CrossRef]
  30. Chowdhury, T.; Mandal, A.; Roy, S.C.; De Sarker, D. Diversity of the genus Ocimum (Lamiaceae) through morpho-molecular (RAPD) and chemical (GC–MS) analysis. J. Genet. Eng. Biotechol. 2017, 15, 275–286. [Google Scholar] [CrossRef] [PubMed]
  31. Nurzyńska-Wierdak, R. Morphological variability and essential oil composition of four Ocimum basilicum L. cultivars. J. Essen. Oil Bear. Plants 2014, 17, 112–119. [Google Scholar] [CrossRef]
  32. Mulugeta, S.M.; Gosztola, B.; Radácsi, P. Morphological and biochemical responses of selected Ocimum species under drought. Herba Polon. 2022, 68, 1–10. [Google Scholar] [CrossRef]
  33. Svecova, E.; Neugebauerov, J. A study of 34 cultivars of basil (Ocimum L.) and their morphological economic and biochemical characteristics using standardized descriptors. Acta Univ. Sapientiae Aliment. 2010, 3, 118–135. [Google Scholar]
  34. Gupta, S.; Srivastava, A.; Shasany, A.K.; Gupta, A.K. Genetics, cytogenetics, and genetic diversity. In The Genus Ocimum: Compendium of Plant Genomes; Springer: Cham, Switzerland, 2018; pp. 73–87. [Google Scholar]
  35. Singh, S.; Lal, R.K.; Maurya, R.; Chanotiya, C.S. Genetic diversity and chemotype selection in genus Ocimum. J. Appl. Res. Med. Arom. Plants 2018, 9, 19–25. [Google Scholar] [CrossRef]
  36. Vieira, R.F.; Goldsbrough, P.; Simon, E. Genetic Diversity of Basil (Ocimum spp.) Based on RAPD Markers. J. Am. Soc. Hort. Sci. 2003, 28, 94–99. [Google Scholar] [CrossRef]
  37. Saran, P.L.; Tripathy, V.; Meena, R.P.; Kumar, J.; Vasara, R.P. Chemotypic characterization and development of morphological markers in Ocimum basilicum L. germplasm. Sci. Hortic. 2017, 215, 164–171. [Google Scholar] [CrossRef]
  38. Saran, P.L.; Damor, H.I.; Lal, M.; Sarkar, R.; Kalariya, K.A.; Suthar, M.K. Identification of suitable chemotype of Ocimum gratissimum L. for cost-effective eugenol production. Ind. Crop. Prod. 2023, 191, 115890. [Google Scholar] [CrossRef]
  39. Abuhashem, Y.S.; Khalil, H.B.; El-Tahawey, M.A.F.A. Exploring the morphological and genetic diversity of Egyptian basil landraces (Ocimum sp.) for future breeding strategies. Beni-Suef Univ. J. Basic Appl. Sci. 2023, 12, 70. [Google Scholar] [CrossRef]
  40. Juškevičienė, D.; Radzevičius, A.; Viškelis, P.; Maročkienė, N.; Karklelienė, R. Estimation of morphological features and essential oil content of basils (Ocimum basilicum L.) Grown under Different Conditions. Plants 2022, 11, 1896. [Google Scholar] [CrossRef] [PubMed]
  41. Malav, P.; Pandey, A.; Bhatt, K.C.; Krishnan, S.G.; Bisht, I.S. Morphological variability in holy basil (Ocimum tenuiflorum L.) from India. Genet. Resour. Crop. Evol. 2015, 62, 1245–1256. [Google Scholar] [CrossRef]
  42. Zheljazkov, V.D.; Callahan, A.; Cantrell, C.L. Yield and oil composition of 38 basil (Ocimum basilicum L.) accessions grown in Mississippi. Agric. Food Chem. 2008, 56, 241–245. [Google Scholar] [CrossRef] [PubMed]
  43. Nurzyńska-Wierdak, R. Morphological and Chemical variability of Ocimum basilicum L. (Lamiaceae). Modern Phytomorph. 2013, 3, 115–118. [Google Scholar] [CrossRef]
  44. Zeljković, Ć.S.; Komzáková, K.; Šišková, J.; Karalija, E.; Smékalová, K.; Tarkowski, P. Phytochemical variability of selected basil genotypes. Ind. Crop. Prod. 2020, 157, 112910. [Google Scholar] [CrossRef]
  45. Cheliku, N.; Karanfilova, I.C.; Stefkov, G.; Karapandzova, M.; Bardhi, N.; Qazimi, B.; Kulevanova, S. Essential oil composition of five basil cultivars (Ocimum basilicum) from Albania. Maced. Pharm. Bull. 2015, 61, 11–18. [Google Scholar] [CrossRef]
  46. Pinto, J.A.O.; Blank, A.F.; Nogueira, P.C.L.; Arrigoni-Blank, M.F.; Andrade, T.M.; Sampaio, T.S.; Pereira, K.L.G. Chemical characterization of the essential oil from leaves of basil genotypes cultivated in different seasons. Med. Arom. Plants 2019, 18, 58–70. [Google Scholar] [CrossRef]
  47. Awasthi, P.K.; Dixit, S.C. Chemical compositions of Ocimum sanctum ‘Shyama’ and Ocimum sanctum ‘Rama’ oils from the plains of Northern India. J. Ess. Oil Bear. Plants 2007, 10, 292–296. [Google Scholar] [CrossRef]
  48. Fuller, N.J.; Pegg, R.B.; Affolter, J.; Berle, D. Variation in growth and development, and essential oil yield between two Ocimum species (O. tenuiflorum and O. gratissimum) grown in Georgia. Hort. Sci. 2018, 53, 1275–1282. [Google Scholar] [CrossRef]
  49. Kumar, A.; Lal, R.K. The consequence of genotype × environment interaction on high essential oil yield and its composition in clove basil (Ocimum gratissimum L.). Acta Ecol. Sin. 2022, 42, 633–640. [Google Scholar] [CrossRef]
  50. Lawrence, B.M. A further examination of the variation of Ocimum basilicum L. In Flavors and Fragrances: A World Perspective; Lawrence, B.M., Mookerjee, B.D., Willis, B.J., Eds.; Elsevier: Amsterdam, The Netherlands, 1988; pp. 161–170. [Google Scholar]
  51. Grayer, R.J.; Kite, G.C.; Goldstone, F.J.; Bryan, S.E.; Paton, A.; Putievsky, E. Intraspecific taxonomy and essential oil chemotypes in sweet basil, Ocimum basilicum. Phytochemistry 1996, 43, 1033–1039. [Google Scholar] [CrossRef] [PubMed]
  52. Varga, F.; Carović-Stanko, K.; Ristić, M.; Grdiša, M.; Liber, Z.; Šatović, Z. Morphological and biochemical intraspecific characterization of Ocimum basilicum L. Ind. Crop. Prod. 2017, 109, 611–618. [Google Scholar] [CrossRef]
  53. Couto, H.G.S.A.; Blank, A.F.; Silva, A.M.O.; Nogueira, P.C.L.; Arrigoni-Blank, M.F.; Nizio, D.A.C.; Pinto, J.A.O. Essential oils of basil chemotypes: Major compounds, binary mixtures, and antioxidant activity. Food Chem. 2019, 293, 446–454. [Google Scholar] [CrossRef] [PubMed]
  54. Tangpao, T.; Chung, H.H.; Sommano, S.R. Aromatic profiles of essential oils from five commonly used Thai basils. Foods 2018, 7, 175. [Google Scholar] [CrossRef] [PubMed]
  55. de Castro, J.A.M.; Monteiro, O.S.; Coutinho, D.F.; Rodrigues, A.A.C.; da Silvad, J.K.R.; Maia, J.G.S. Seasonal and circadian study of a thymol/γ-terpinene/p-cymene type oil of Ocimum gratissimum L. and its antioxidant and antifungal effects. J. Braz. Chem. Soc. 2019, 30, 930–938. [Google Scholar] [CrossRef]
  56. Kumar, A.; Mishra, P.; Rodrigues, V.; Baskaran, K.; Verma, R.S.; Padalia, R.C.; Sundaresan, V. Delineation of Ocimum gratissimum L. complex combining morphological, molecular, and essential oils analysis. Ind. Crop. Prod. 2019, 139, 111536. [Google Scholar] [CrossRef]
  57. Pharmacopoeia Hungarica, 7th ed.; Medicina Könyvkiadó: Budapest, Hungary, 1986; Volume 1, pp. 395–398.
  58. van Den Dool, H.; Kratz, P. A generalization of the retention index system including linear temperature programmed gas-liquid partition chromatography. J. Chromatogr. A 1963, 11, 463–471. [Google Scholar] [CrossRef]
  59. Adams, R.P. Identification of Essential Oil Components by Gas Chromatography/Mass Spectrometry, 4th ed.; Allured: Carol Stream, IL, USA, 2007. [Google Scholar]
Plants 13 00064 g001
Figure 1. Morphological cluster analysis among basil genotypes.
Figure 1. Morphological cluster analysis among basil genotypes.
Plants 13 00064 g001
Plants 13 00064 g002
Figure 2. Principal component analysis plot for morphological traits among the 15 genotypes.
Figure 2. Principal component analysis plot for morphological traits among the 15 genotypes.
Plants 13 00064 g002
Plants 13 00064 g003aPlants 13 00064 g003b
Figure 3. Variability in essential oil production of 15 Ocimum genotypes (A) essential oil content and (B) essential oil yield. Values are presented as Mean ± SD; Different letters indicate significantly different means.
Figure 3. Variability in essential oil production of 15 Ocimum genotypes (A) essential oil content and (B) essential oil yield. Values are presented as Mean ± SD; Different letters indicate significantly different means.
Plants 13 00064 g003aPlants 13 00064 g003b
Plants 13 00064 g004
Figure 4. Essential oil composition cluster analysis.
Figure 4. Essential oil composition cluster analysis.
Plants 13 00064 g004
Plants 13 00064 g005
Figure 5. Principal component plot analysis of volatile oil composition among the 15 genotypes.
Figure 5. Principal component plot analysis of volatile oil composition among the 15 genotypes.
Plants 13 00064 g005
Plants 13 00064 g006
Figure 6. Weather conditions during the experimental period (June to September 2022).
Figure 6. Weather conditions during the experimental period (June to September 2022).
Plants 13 00064 g006
Plants 13 00064 g007
Figure 7. Morphology of the 15 Ocimum genotypes.
Figure 7. Morphology of the 15 Ocimum genotypes.
Plants 13 00064 g007
Table 1. Growth parameters among Ocimum species.
Table 1. Growth parameters among Ocimum species.
GenotypesPH (cm)CD (cm)LL (cm)LW (cm)LA (cm2)HLW (g)
Anise 47.7 ± 3.9 c,d50.0 ± 2.4 a,b6.2 ± 0.3 e,f2.3 ± 0.2 i,j7.7 ± 1.8 e–g31.7 ± 2.6 g
Clove 43.0 ± 2.2 d,e52.5 ± 6.3 a6.1 ± 0.5 e–g3.1 ± 0.2 f–h10.4 ± 2.0 d–f33.4 ± 3.1 g
Fahéj illatú50.7 ± 2.8 a–c47.8 ± 3.4 a,b7.6 ± 0.7 c4.3 ± 0.4 c,d14.8 ± 4.8 d70.0 ± 5.1 c
Fino Verde23.0 ± 3.0 g32.5 ± 4.7 e,f1.8 ± 0.3 i0.9 ± 0.1 k1.4 ± 0.3 g3.5 ± 0.6 j
Licorice 54.3 ± 4.4 a,b52.5 ± 4.6 a5.8 ± 0.4 e–g3.3 ± 0.3 f,g9.9 ± 2.2 d–f30.9 ± 3.2 g
Mammoth 43.3 ± 3.2 d,e38.3 ± 4.7 c–e12.4 ± 1.3 a8.6 ± 1.1 a52.0 ± 1.2 a214.0 ± 17.1 a
Mrihani 44.7 ± 3.8 c,d44.8 ± 5.1 a–c7.2 ± 0.6 c,d4.9 ± 0.6 c16.0 ± 3.4 d62.3 ± 3.9 d
Mrs. Burns 47.2 ± 5.0 c,d45.2 ± 4.5 a–c4.1 ± 0.6 h1.9 ± 0.3 j4.5 ± 1.3 f,g13.5 ± 2.3 i
Thai tömzsi50.8 ± 1.5 a–c47.3 ± 4.8 a–c6.1 ± 0.8 e–g3.1 ± 0.2 f–h8.2 ± 1.2 e,f42.4 ± 4.3 f
Thai hosszú50.8 ± 2.8 a–c50.5 ± 3.3 a,b5.2 ± 0.3 g2.7 ± 0.4 g–i7.7 ± 1.9 e–g53.8 ± 4.5 e
Vietnamese 37.8 ± 1.5 e,f34.3 ± 2.7 d–f5.4 ± 0.5 f,g2.6 ± 0.2 h,i6.8 ± 1.8 e–g21.0 ± 2.8 h,i
Green holy basil 43.7 ± 3.3 d,e47.8 ± 8.8 a,b5.4 ± 0.2 f,g3.4 ± 0.1 e,f9.9 ± 0.7 d–f34.9 ± 4.4 g
Vana holy basil48.5 ± 4.7 b–d27.2 ± 5.3 f6.6 ± 0.3 d,e4.0 ± 0.1 d,e12.8 ± 2.9 d,e27.3 ± 2.7 g,h
Lemon basil 34.0 ± 3.1 f42.5 ± 7.1 b–d4.1 ± 0.3 h2.0 ± 0.3 j22.6 ± 2.6 c18.5 ± 1.9 i
African basil 56.3 ± 4.7 a32.8 ± 2.4 e,f10.3 ± 1.4 b6.9 ± 0.7 b36.6 ± 9.6 b148.0 ± 12.8 b
Values are presented as Mean ± SD; PH: plant height, CD: canopy diameter, LL: leaf length, LW: leaf width, LA: leaf area, HLW: hundred leaf weight, Different letters indicate significantly different means.
Table 2. Variation in reproductive traits and yield among Ocimum species.
Table 2. Variation in reproductive traits and yield among Ocimum species.
GenotypesIL (cm)NI TSW (g)FHW (g/Plant)DHW (g/Plant)
Anise 13.5 ± 1.0 f,g74.2 ± 13.4 c,d1.1 ± 0.1 d249.2 ± 61.1 a–d60.0 ± 16.2 a–d
Clove 16.5 ± 1.8 e–g66.5 ± 4.4 c–e1.7 ± 0.1 a403.0 ± 123.2 a95.2 ± 30.7 a
Fahéj illatú29.0 ± 4.5 a60.3 ± 27.3d e1.6 ± 0.1 a,b331.3 ± 133.0 a,b72.3 ± 24.5 a–c
Fino Verde6.5 ± 1.8 g152.7 ± 31.4 a0.9 ± 0.0 e189.7 ± 49.1 b–e44.3 ± 10.5 b–e
Licorice 25.7 ± 2.1 a–c91.0 ± 13.2 b–d1.5 ± 0.1 a–c350.7 ± 61.7 a,b91.8 ± 31.0 a
Mammoth 14.8 ± 14.8 f,g70.3 ± 6.3 c,d1.5 ± 0.0 a–c396.7 ± 91.6 a70.2 ± 17.8 a–c
Mrihani 19.7 ± 2.4 d,e68.8 ± 11.5 c–e1.4 ± 0.0 b,c212.7 ± 21.6 b–e49.3 ± 14.6 b–e
Mrs. Burns 28.8 ± 1.9 a94.5 ± 24.2 b,c1.4 ± 0.0 b,c128.3 ± 82.1 c–e36.0 ± 24.1 c–e
Thai tömzsi24.3 ± 2.5 b,c31.3 ± 3.0 f1.4 ± 0.1 b,c408.7 ± 116.3 a82.0 ± 22.7 a,b
Thai hosszú 27.2 ± 2.3 a,b90.3 ± 18.7 b–d1.6 ± 0.0 a–c355.0 ± 85.4 a,b82.7 ± 17.8 a,b
Vietnamese basil18.5 ± 2.2 e,f22.7 ± 2.9 f1.3 ± 0.1 c,d82.0 ± 17.2 e18.5 ± 4.7 e
Green holy basil17.3 ± 1.2 e–g108.5 ± 28.7 b0.5 ± 0.0 f284.7 ± 117.4 a–c76.0 ± 24.2 a–c
Vana holy basil14.7 ± 1.2 f,g39.0 ± 6.9 e,f1.1 ± 0.0 d94.8 ± 11.3d e24.2 ± 4.7 d,e
Lemon basil22.8 ± 2.8 c,d64.2 ± 8.1 c–e1.5 ± 0.0 a–c268.7 ± 132.976.17 ± 35.8 a–c
African basil 14.7 ± 1.3 f,g72.7 ± 6.3 c,d1.3 ± 0.1 c,d408.3 ± 39.1 a84.3 ± 7.0 a,b
Values are presented as Mean ± SD; IL: Inflorescence length; NI: Number of inflorescences; TSW: thousand seed weight; FHW: fresh herb weight; DHW: dry herb weight; Different letters indicate significantly different means.
Table 3. Essential oil compositions vary among sweet basil cultivars.
Table 3. Essential oil compositions vary among sweet basil cultivars.
ComponentRTLRIAniseCloveFahéj IllatúFino VerdeLicoriceMammothMrihaniMrs. BurnsThai HosszúThai TömzsiVietnamese Basil
β-Myrcene 0.10.20.10.70.10.31.20.10.40.40.7
1,8-Cineole8.4410343.62.62.412.15.34.28.20.31.95.02.6
(E)-Ocimene 8.9610460.42.70.20.20.20.10.20.31.41.01.6
Linalool10.88109712.211.828.132.719.332.82.519.52.31.82.5
Camphor12.6911441.00.50.41.80.80.30.80.01.91.20.3
Terpinen-4-ol13.9711751.40.60.90.12.05.40.11.70.50.10.1
Estragole14.83119625.162.21.50.41.67.366.921.965.364.067.4
Nerol16.1412270.0 6.6
Neral (citral b)16.7212380.0 5.5
Geranial (citral a)18.0012680.0 0.0 7.1
Isobornyl acetate18.5212841.00.30.32.20.60.31.40.00.50.72.9
(Z)-Methyl cinnamate19.3412995.4 4.7 8.3
Eugenol21.491361 2.08.30.01.8 0.1
(E)-Methyl cinnamate22.64139428.7 34.8 42.70.2 0.20.20.3
β-Elemene22.921391 0.6 2.9 2.20.81.60.70.60.5
Methyl eugenol23.4814110.41.10.10.40.10.10.70.14.94.60.8
(E)-β-Caryophyllene24.0014200.30.20.50.30.20.40.72.70.20.40.3
trans-α-Bergamotene24.6914371.12.10.94.0 8.4 1.23.41.13.4
Germacrene D26.4914821.51.32.42.51.53.80.52.00.80.40.3
α-Bulnesene27.4815061.00.41.52.91.22.00.51.10.60.60.3
cis-γ-Cadinene27.8o15151.21.11.7 1.12.9 1.11.00.91.1
cis-α-Bisabolene28.951544 2.7
Maaliol29.8315800.9 0.41.8 0.1 0.1
Caryophyllene oxide30.4615900.3 0.10.10.10.1 2.60.31.00.5
τ-Cadinol32.6216444.44.66.18.44.710.26.74.64.04.93.5
others (<1%) 7.16.29.118.17.612.97.913.76.27.310.6
Total identified (%) 97.198.597.898.197.897.599.196.596.696.299.8
Monoterpenes 1.44.00.93.41.62.53.50.92.72.63.3
Oxygenated monoterpenes 20.717.734.452.330.045.013.446.37.8410.712.0
Sesquiterpenes 7.17.29.520.75.725.05.513.58.15.37.4
Oxygenated sesquiterpenes 8.26.29.511.97.715.18.111.67.49.36.7
Phenylpropanes 59.863.643.510.052.89.868.824.770.669.268.8
RT—retention time. LRI—linear retention index relative to C9-C23 n-alkanes on an HP-5MS capillary column.
Table 4. Essential oil composition varies among the three Ocimum species.
Table 4. Essential oil composition varies among the three Ocimum species.
ComponentRTLRIGreen Holy Basil Vana Holy Basil Lemon
Basil 		African Basil
β-myrcene7.099940.2 3.1
α-Terpinene7.931018 0.1 2.7
p-Cymene8.171028 20.7
γ-Terpinene9.361056 10.6
1,8-Cineole8.4410348.3 0.70.1
(E)-Ocimene 8.9610460.72.60.3
cis-Sabinene hydrate9.6810.680.61.4 1.2
Linalool10.88109712.12.83.50.3
Terpinen-4-ol13.9711750.20.6 1.1
Estragole14.83119610.10.461.40.8
Isobornyl acetate18.521284 1.50.1
Thymol18.811290 42.1
Nerol16.1412270.9 2.1
Neral (citral b)16.7212380.8 6.1
Geranial (citral a)18.0012681.2 7.8
Eugenol21.4913617.027.30.1
α-Copaene22.2513770.22.70.1
(E)- β-Caryophyllene24.0014201.16.81.12.2
trans-α-Bergamotene24.6914372.30.00.9
α-Humulene25.3814541.20.70.30.3
Germacrene D26.4914820.65.40.2
β-Bisabolene27.63150814.1 0.1
cis-α-Bisabolene28.9515444.9 1.3
Caryophyllene oxide30.4615903.214.42.6
Humulene epoxide II31.4416152.41.00.3
τ-Cadinol32.6216442.70.40.6
3-iso-Thujopsanone 33.001653 1.8
Cubenol33.131658 2.9
others (<1%) 16.023.57.911.9
Total identified (%) 90.896.395.597.1
Monoterpenes 3.80.742.742.7
Oxygenated monoterpenes 28.19.022.85.7
Sesquiterpenes 27.314.24.34.3
Oxygenated sesquiterpenes 15.334.74.60.3
Phenylpropanes 18.634.863.445.3
RT—retention time. LRI—linear retention index relative to C9-C23 n-alkanes on an HP-5MS capillary column.
Table 5. Soil characteristics of the experimental field.
Table 5. Soil characteristics of the experimental field.
pH
H2O		Humus
%		KANO3-N
mg/kg		P2O5
mg/kg		K2O
mg/kg		Na
mg/kg		Mg
mg/kg		Mn
mg/kg		Zn
mg/kg		Cu
mg/kg		SO4
mg/kg
7.581.70<2511.36544.43177.3630.11377.9358.484.902.4671.58
Table 6. List of basil species, cultivar name, and origin of the 15 basil accessions.
Table 6. List of basil species, cultivar name, and origin of the 15 basil accessions.
Accession No. Species Cultivar/Common Name Sources
LAMIOCI60O. basilicumAnise Department gene bank
LAMIOCI61O. basilicumClove Department gene bank
LAMIOCI62O. basilicumFahéj illatúDepartment gene bank
LAMIOCI63O. basilicumFino VerdeDepartment gene bank
LAMIOCI64O. basilicumLicorice Department gene bank
LAMIOCI65O. basilicumMammoth Department gene bank
LAMIOCI66O. basilicumMrihani Department gene bank
LAMIOCI67O. basilicumMrs. Burns Department gene bank
LAMIOCI68O. basilicumThai tömzsi Department gene bank
LAMIOCI69O. basilicumThai hosszú Department gene bank
LAMIOCI70O. basilicumVietnamese basil Department gene bank
LAMIOCI55O. sanctumGreen holy basil Department gene bank
LAMIOCI75O. citrodoraLemon basil Department gene bank
LAMIOCI77O. gratissimumVana holy basilDepartment gene bank
LAMIOCI78O. gratissimumAfrican basil Department gene bank
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Mulugeta, S.M.; Pluhár, Z.; Radácsi, P. Phenotypic Variations and Bioactive Constituents among Selected Ocimum Species. Plants 2024, 13, 64. https://doi.org/10.3390/plants13010064

AMA Style

Mulugeta SM, Pluhár Z, Radácsi P. Phenotypic Variations and Bioactive Constituents among Selected Ocimum Species. Plants. 2024; 13(1):64. https://doi.org/10.3390/plants13010064

Chicago/Turabian Style

Mulugeta, Sintayehu Musie, Zsuzsanna Pluhár, and Péter Radácsi. 2024. "Phenotypic Variations and Bioactive Constituents among Selected Ocimum Species" Plants 13, no. 1: 64. https://doi.org/10.3390/plants13010064

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop