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Article

Biochemical and Morphological Traits of Wild Myrtle Populations for Horticultural Use

by
Donya Shahbazian
1,
Akbar Karami
1,* and
Nazim S. Gruda
2
1
Department of Horticultural Sciences, School of Agriculture, Shiraz University, Shiraz 71441, Iran
2
Department of Horticultural Sciences, INRES—Institute of Crop Science and Resource Conservation, University of Bonn, 53113 Bonn, Germany
*
Author to whom correspondence should be addressed.
Horticulturae 2025, 11(3), 233; https://doi.org/10.3390/horticulturae11030233
Submission received: 3 February 2025 / Revised: 18 February 2025 / Accepted: 19 February 2025 / Published: 21 February 2025
(This article belongs to the Special Issue Wild Plant Species as Potential Horticultural Crops: An Opportunity for Farmers and Consumers—2nd Edition)
Browse Figure
Versions Notes

Abstract

:
Myrtle (Myrtus communis L.), an evergreen shrub belonging to the Myrtaceae family, is widely valued for its applications in the cosmetic, hygienic, and medicinal industries. This plant produces berries in two colors—white and black—with black berries receiving increasing attention due to their superior antioxidant properties. This study investigates black myrtle berries’ morphological and biochemical characteristics from eight prominent natural habitats in Fars Province, southwestern Iran. The results reveal significant variations in the morphological (such as fruit length and diameter, fruit length-to-diameter ratio, seed length and diameter, fruit weight, pulp weight, seed weight, pulp-to-seed ratio, and number of seeds) and biochemical attributes among the studied populations. The longest fruit was from the Kherqeh (KH) (8.29 mm) population, while the shortest was from the Baghnari (BN) (5.85 mm) population. The largest fruit diameter was also from KH (6.83 mm), which did not show a significant difference compared to the Zanjiran (ZF) population, while the smallest fruit diameter was from BN (5.12 mm), which did not differ significantly from the Kavar (KA), Simakan (SM), Kouhmareh Road (JK), or Atashkadeh (AT) populations. Notably, all populations exhibited high levels of phenolic compounds, ranging from 660 to 1846 mg per 100 g of fresh weight, and potent antioxidant activity, as indicated by low half-maximal inhibitory concentrations ranging from 0.018 to 0.187 mg per gram. Correlation analyses further demonstrated that altitude and specific soil properties influenced the biochemical traits of the berries to varying degrees. These findings offer valuable scientific insights for selecting and utilizing specific myrtle populations in horticulture, particularly for breeding programs to maximize antioxidant properties and phenolic content.

1. Introduction

Myrtle (Myrtus communis L.), commonly known as common myrtle, belongs to the Myrtaceae family. This plant is native to Mediterranean regions, including Portugal, southern France, Spain, southern Turkey, southern Italy, Greece, Israel, Lebanon, Iran, Afghanistan, Libya, Morocco, Algeria, and Tunisia [1,2]. It is a shrub or small tree with dense foliage, reaching heights of over 2.5 m. The leaves are small, leathery, pointed or oval-shaped, dark green, and morphologically classified into three forms—decussate, spiral, and tricussate—with the decussate arrangement being the most common [3]. The fruit appears in black and white varieties, containing numerous seeds (Figure 1). Insects and wind pollinate these plants, while birds generally disperse their seeds [4].
The nutritional and medicinal value of myrtle fruit has been extensively documented. This fruit is used in alcoholic beverages and the well-known Italian soft drink “Chinotto” in Sardinia, Italy, due to its high concentration of oenothein B [5]. Myrtle has been associated with various medicinal benefits, including wound healing in diabetic patients, potential support in managing respiratory symptoms observed during COVID-19, enhancing thyroid function, healing burn wounds, lowering high blood pressure, alleviating respiratory and pulmonary disorders, reducing stress and insomnia, treating oral ulcers, and protecting the liver [5,6]. Research by Cruciani et al. [7] indicates that myrtle may slow the aging process in cells exposed to oxidative stress and can help prevent age-related diseases. Additionally, myrtle extract has been found to increase the post-harvest shelf life of fruits and reduce microbial loads in salmon and red meat. When added to milk, myrtle fruit extract enhances nutritional value and lowers blood urea levels without affecting milk coagulation or shelf life. Moreover, the extract derived from the industrial waste of myrtle fruit can protect cells from oxidative stress damage, making it valuable in food formulations [5]. Myrtle fruit is rich in anthocyanins (31 types), flavonoids (11 types), antioxidants, tannins, vitamins (A, E, B), and essential elements such as selenium, zinc, iron, potassium, phosphorus, fiber, protein, fat, oleic acid, linolenic acid, palmitic acid, and linoleic acid [5,7,8,9,10]. The European Scientific Associations have recognized myrtle fruit as a significant source of anthocyanins, flavonoids, and antioxidants [11].
The biochemical composition of the fruit, particularly its phenolic and antioxidant compounds, is primarily influenced by genotype, growing conditions, climatic factors, fruit maturity stage, and soil properties, which are typically enhanced under environmental stress [2,12,13,14]. Despite the myrtle plant’s widespread distribution in Iran, research on its fruit’s morphological and biochemical characteristics remains limited. This study evaluates the biochemical and morphological characteristics of black myrtle fruit collected from eight key Fars Province, Iran, distribution areas. Additionally, it examines the effects of altitude and soil characteristics on the fruit’s biochemical properties. The results provide a scientific foundation for future research in breeding programs and food industries.

2. Materials and Methods

2.1. Plant Material and Fruit Collection

Black myrtle fruit samples were collected from mid-November to early December 2024 from eight natural habitats in Fars Province (Zanjiran (ZF), Kouhmareh Road (JK), Tang Kherqeh (KH), Kavar (KA), Simakan (SM), Atashkadeh (AT), Sarvegarm (SF), and Baghnari (BN)) (Table 1) at full maturity. Three replications per population were conducted, with data collected from nine individuals per population. The fruit samples were transferred to the Medicinal Plants Laboratory of the School of Agriculture at Shiraz University. After removing external contaminants, 60 fruits from each replication were set aside for morphological measurements, while 300 g per replication was stored at −80 °C for biochemical analysis. Soil samples were also collected from 0–30 cm depth and analyzed at the Soil Science Laboratory of Shiraz University (Table 1).

2.2. Chemicals and Reagents

The chemicals and reagents were purchased from Sigma-Aldrich (St. Louis, MO, USA) and Fluka (Heidelberg, Germany). All other chemicals and reagents used were of the highest purity commercially available.

2.3. Measurement of Morphological Characteristics

2.3.1. Weight of Flesh, Seeds, and Fruit

To determine the weight of flesh, seeds, and fruit, 20 fruits from each individual were selected and measured using a digital scale with an accuracy of 0.001 g. Two groups of fruits, consisting of 20 from each individual, were used to determine the weight accurately. One group was measured for pulp and seed weight, while the other was measured separately for total fruit weight.

2.3.2. Length and Diameter of Fruit and Seeds

To determine the length and diameter of the fruit and seeds, 20 fruits from each individual were randomly selected and measured using a digital caliper with an accuracy of 0.01 mm. For the fruit length-to-diameter ratio, the length data were divided by the diameter of the fruits.

2.3.3. Number of Seeds

To determine the number of seeds, 20 fruits from each individual were randomly selected and counted.

2.4. Measurement of Biochemical Characteristics

2.4.1. Total Phenol Content (TPC)

A methanol solvent (1:3 ratio) was used to extract phenolic compounds. Initially, 1 g of fruit flesh was mixed with 3 mL of ethanol and stored in a cold room for 12 to 14 h. The sample was then thoroughly mixed with methanol using a mortar and pestle and transferred to a sealed tube. The samples were centrifuged for 15 min at 6000 rpm, and the supernatant was used to measure phenol content. The Folin–Ciocalteu method was employed, where 700 µL of the methanolic extract was combined with 140 µL of 50% Folin reagent and kept at room temperature for 3 min. Then, 700 µL of 2% sodium carbonate was added, and the mixture was left at room temperature for 30 min before being centrifuged for 5 min at 13,400 rpm. The absorbance was read at 750 nm using an Epoch device (BioTek, Charlotte, VT, USA, with Gen5™ Data Analysis Software). The absorbance data were converted to various concentrations of gallic acid (prepared from the Sigma brand in Germany) by plotting the standard curve of gallic acid using Excel software. The recorded absorbances from the samples were placed on the y-axis, and the x-axis, or concentration, was obtained. The results were expressed as milligrams of gallic acid equivalent per 100 g of fresh weight (mg GAE/100 gFW).

2.4.2. Diphenyl-1-picrylhydrazyl (DPPH) Radical Scavenging Capacity Assay

The percentage of free radical inhibition was determined using the DPPH assay method by Burits et al. [15]. A volume of 100 µL of the methanolic extract at different concentrations (0–250 mg/mL) was added to 5 mL of DPPH solution. In the control (blank) solution, 100 µL of methanol was added instead of the extract. The solutions were vigorously shaken for 10 s and kept for 30 min at room temperature in the dark. Absorbance was measured at 517 nm using a BioTek Epoch device (USA). The percentage of free radical inhibition (I%) was calculated using the following equation:
I% = [(A517 blank − A517 sample)/A517 blank] × 100
A517 blank and A517 sample refer to the absorbance of the blank and the sample at 517 nm, respectively. The IC50 value, representing the concentration required to neutralize 50% free radicals, was used to compare antioxidant activity.

2.4.3. Total Anthocyanin Content

A 10 mg sample of frozen fruit flesh was placed in a centrifuge tube, and 1 mL of acidic methanol (1% hydrochloric acid) was added. The extract was stored overnight at 4 °C. Then, it was centrifuged for 10 min at 10,500 rpm and read at two wavelengths of 530 and 657 nm [16].

2.4.4. Total Soluble Solids (TSS)

A quantity of 0.1 gr of dried fruit powder was placed in a Falcon tube, and 10 mL of 80% ethanol was added and mixed. The tubes were centrifuged for 10 min at 5000 rpm, then the supernatant was separated, and another 10 mL of 80% ethanol was added to the sediment in the tube and centrifuged again. The supernatant was added to the previous solution. A 5% phenol solution was prepared. A total of 1 mL of the target solution and 1 mL of Folin’s solution were placed in a test tube, and 5 mL of concentrated sulfuric acid was immediately added. The resulting mixture was stirred for 15 s. Afterward, the tubes were placed in ice water to cool. Finally, their absorbance was measured at a wavelength of 490 nm using a visible spectrophotometer. Pure D-glucose was used to draw the standard curve. For this purpose, solutions containing glucose with concentrations ranging from 10 to 200 µg mL−1 were prepared, and their absorbance was read at a wavelength of 490 nm using a BioTek Epoch device (USA) [17].

2.4.5. Titratable Acidity (TA)

To extract total acid, 2.5 gr of fruit was thoroughly crushed using a mortar and pestle, and then 10 mL of distilled water was added. The extract was then centrifuged, and titration was performed with 0.1 standard NaOH to reach a pH of 2.8 in the presence of phenolphthalein. The results were expressed in terms of malic acid [18]. The percentage of acid was calculated using the following equation:
% Acid = N × V1 × Eq.wt/V2 × 10
V1 = normalized NaOH, V2 = sample size, Eq.wt = molecular weight of the predominant acid (malic acid C4H6O5 = 134.09 g/mol).

2.4.6. Total Protein Content

To measure protein concentration using the Bradford method, 100 µL of protein extract was added to test tubes containing 5 mL of Bradford reagent and was quickly vortexed. After 2 min, the absorbance was read using an Epoch device (USA) at a wavelength of 595 nm. Bovine serum albumin was used to construct the standard curve. For this purpose, solutions containing bovine serum albumin at various concentrations were prepared, and their absorbance was read at a wavelength of 595 nm. The total protein content in the samples was calculated and reported based on the absorbance values read from the standard curve [19].

2.5. Statistical Analysis

A completely randomized design with three replications was used for the experiment. All data were analyzed using SAS software (version 4.2), and means were compared using the LSD test at 1% and 5% significance levels and correlation analysis between traits.

3. Results and Discussion

3.1. Evaluation of Morphological Characteristics of Myrtle Fruit from Different Populations

The results of the evaluation of morphological characteristics are presented in Table 2. The longest fruit was from KH (8.29 mm), while the shortest was from BN (5.85 mm). The largest fruit diameter was also from KH (6.83 mm), which did not show a significant difference compared to the ZF population, while the smallest fruit diameter was from BN (5.12 mm), which did not differ significantly from the KA, SM, JF, and AT populations. The highest length-to-diameter ratio was found in the SF region (1.25), while the lowest ratio was in ZF (1.06). The BN population had the longest seed (3.22 mm), while the shortest seed was from SM (2.21 mm), which did not show a significant difference compared to KH. BN had the largest seed diameter (1.11 mm) among the different populations, while the smallest seed diameter was from SM (0.81 mm), which did not differ significantly from KA. The heaviest fruit was from KH (2.35 g), and the lightest was from BN (1.72 g). The heaviest seed was from KH (1.19 g), while BN had the lowest seed weight (0.81 g) among the studied populations. The highest flesh weight of the fruit was from SF (1.82 g), while the lowest flesh weight was from BN (1.51 g), which did not show a significant difference compared to SM. The highest flesh-to-seed ratio was found in KH (0.78), while the lowest was in SM (0.50), which did not differ significantly from BN. The highest number of seeds was recorded in ZF (5.1), which did not show a significant difference compared to the KH population. The lowest number of seeds was found in BN (1.67). A high number of seeds in the fruit and a low flesh-to-seed ratio negatively affect fresh consumption and processing industries, such as in beverage production, for myrtle. This is because the amount of tannin in the fruit flesh reaches a minimum at ripening; however, the seeds retain tannins until the fruit ripens and enter beverages during processing, causing an astringent taste [2]. However, the high tannin content in the pharmaceutical industry, especially ellagitannins found in seeds, can be advantageous. Ellagitannins are a complex class of bioactive compounds or hydrolyzable tannins, identified by one or more units of hexa-hydroxy diphenyl, found in limited quantities in the seeds of dicotyledonous angiosperm myrtle [20]. These compounds have been shown to improve overall health, reduce inflammation, and lower the risk of cardiovascular diseases, neurological disorders, and cancer. There have been few studies on the morphological characteristics of myrtle fruit. Wahid et al. [21] reported significant differences in myrtle fruit morphology among populations in Morocco. Their findings on the morphological characteristics of the fruit from three growth sites are consistent with our results. They also stated that the differences in fruit morphology are primarily of genetic origin. This study examined the morphological characteristics of two varieties, “Barbara” and “Daniela”. “Barbara” produced fewer seeds (1.8) and had a higher flesh-to-seed ratio (3.19) than “Daniela”, making it more suitable for commercial fresh consumption. Meanwhile, “Daniela”, due to its significant vegetative growth potential, can be used as a dual-purpose variety, ideal for both leaf and fruit production in the pharmaceutical industry and beverage production [22]. An examination of the morphological characteristics of myrtle fruit across seven growth sites in Italy showed significant differences in fruit morphology across regions. The fruit length varied between 9.03 mm and 18.7 mm, the fruit diameter ranged from 5.74 mm to 8.22 mm, and the length-to-diameter ratio varied from 1.10 to 1.29 [23]. The results of this study indicated a high degree of morphological variation in ecologically similar sites, possibly due to genetic diversity or an adaptive mechanism in response to climatic conditions [23,24].

3.2. Evaluation of Biochemical Characteristics of Myrtle Fruit from Different Populations in Fars Province

The results of the biochemical characteristics evaluation of the fruit are presented in Table 3. The IC50 values ranged from 0.018 mg of dry matter per milliliter to 0.882 mg per milliliter across different regions. The IC50 values in various areas were compared with the IC50 of the synthetic antioxidant butylated hydroxytoluene (BHT) (IC50 = 0.0407 mg/mL DW) as a positive control. The lowest IC50 was recorded for SF (IC50 = 0.018), which was lower than that of BHT, indicating that the antioxidant activity of SF fruit was higher than that of the synthetic antioxidant BHT. The highest IC50 was associated with AT, which did not significantly differ from ZF, KH, or JF. Numerous studies have reported the high antioxidant activity of myrtle fruit [2,11,13,25,26]. An investigation into the differences in antioxidant activity among various parts of the fruit (whole fruit, seeds, and pericarp) of Myrtus communis var. italica in Tunisia showed that all parts exhibited high antioxidant activity. Among these, the seeds had the highest antioxidant activity (IC50 = 8 μg/mL), even greater than the synthetic antioxidant BHT (IC50 = 25 μg/mL). The antioxidant activities of the other parts of the fruit were close to that of the synthetic antioxidant [26], which was consistent with our results. The phenol content ranged from 660 to 1846 mg per 100 g of fresh material. BN had the highest phenol content among the studied areas (1846 mg per 100 g of fresh material), while KH had the lowest (660 mg per 100 g of fresh material), which was not significantly different from KA and JF. Melito et al. [23] reported the phenol content of myrtle fruit in seven different habitats in Sicily, Italy, ranging from 2466 to 3800 mg/100 g DW. Additionally, a study examining the phenol content in different parts of Myrtus communis var. italica fruit found that the phenol content varied among different parts of the fruit. The phenol content in the seeds was 23.87 mg/g DW, in the pericarp (fruit flesh), 2.76 mg/g DW, and in the whole fruit, 13.73 mg/g DW [27]. Since this study measured only the phenol content in the pericarp, the pericarp of the myrtle fruits analyzed here had a higher phenol content (825–1824 mg/100 g DW) than those in the previous study. The phenol content of the two cultivars, “Barbara” and “Daniela”, grown in Alghero, Italy, over two consecutive years and at different stages of fruit development, showed significant variation each year and at different stages of growth. The phenol content of the fruit decreased as it approached the ripening stage [27].
A study on four genotypes of myrtle fruit collected from different regions of Antalya, Turkey (two black genotypes and two white genotypes), revealed that black fruits contained higher levels of phenolic compounds than white fruits. Additionally, the phenol content varied even among genotypes with the same fruit color, possibly due to genetic and ecological factors. The predominant phenolic compounds in black myrtle fruit included chlorogenic acid, syringic acid, naringin, gallic acid, caffeic acid, and p-hydroxybenzoic acid. In contrast, in white fruit, naringin, gallic acid, and chlorogenic acid were present [28].
The anthocyanin content ranged from 1.53 to 311 mg per 100 g of fresh weight. The highest anthocyanin content (311 mg per 100 g of fresh weight) was found in the SF genotype, while the lowest was in the SM region (53 mg per 100 g of fresh weight). Fadda and Mulas [18] reported that anthocyanin content in myrtle fruit varied over consecutive years and at different stages of growth. In 2005, the anthocyanin content was 117 mg/100 g FW; in 2006, it decreased to 70 mg/100 g FW. With the onset of fruit ripening, the level of anthocyanins increased. The variation in anthocyanin levels over consecutive years may be due to climatic conditions. Temperature is a significant factor influencing anthocyanin production, as lower nighttime temperatures enhance the activity of the enzymes involved in the biosynthetic pathway of anthocyanins [29]. A study on the anthocyanin content in different parts of the fruit (pericarp, whole fruit, seeds) of M. communis var. italica in Tunisia showed that the highest anthocyanin content (4.64 mg/g FW) was found in the entire fruit. The anthocyanin content in the fruit’s pericarp was 3.47 mg/g DW, while the seeds contained no anthocyanins. The soluble solid content varied between 0.8% and 2.4%. JF had the highest soluble solid content (2.5%), which was not significantly different from the AT region. The lowest soluble solid content was measured in SM (0.81%), which did not differ substantially from the KH and SF regions. The acid content varied between 0.07% and 0.18%. The highest acid content was associated with BN (0.18%), which did not significantly differ from KH and AT. The lowest acid content was found in SM (0.07%), although it was not significantly different from JF. The ratio of soluble solids to acid varied between 6.31 and 24. The JF population had the highest ratio of soluble solids to acid (22.42) among the different regions. The lowest ratio of soluble solids to acid was found in KH, which did not differ significantly from SF. The protein content varied between 0.27 and 1.7 mg/g DW. The highest protein content was found in ZF (1.7 mg/g DW), which did not differ significantly from JF. The lowest protein content was associated with the BN region (0.27 mg/g DW), which did not differ substantially from the SF region. The fruit sugar content of the two cultivars, Barbara and Daniela, from Italy, was determined. The sugar content values at full ripeness in the two varieties, “Barbara” and “Daniela”, were 8.28% and 7.56%, respectively. The authors also stated that the sugar content increases as the fruit ripens, and there was no significant difference in sugar content over two consecutive years. In another study, the crude protein content of myrtle fruit was reported to be 17.41% [30].
Çakmak and colleagues [10] investigated the effects of freezing, sun drying, and microwave drying on the nutritional value of wild and cultivated fruit populations in Osmaniye, Turkey. The results showed that both types of fruit were rich in vitamins A, B, and E and essential elements such as selenium, zinc, iron, and copper. The levels of vitamins A and E, cyanocobalamin, thiamine, nicotinamide, and folic acid were high in wild and cultivated fruits. In contrast, the level of riboflavin was higher in cultivated fruits compared to wild ones. No significant differences were observed between fresh and frozen fruits regarding biochemical parameters. Thus, freezing was identified as the most suitable method for preserving myrtle fruits.
AlJuhaimi and colleagues [8] reported potassium, phosphorus, and iron levels in fruits collected from Mersin, Turkey, as 5212.77, 949.08, and 3.76 mg/kg, respectively. A study comparing the antioxidant activity, phenolic compounds, and fatty acids of myrtle fruit, tree bark, and seeds revealed that all three exhibited high antioxidant activity and significant amounts of phenolic compounds. Therefore, these products can serve as sources of natural antioxidants and potential substitutes for synthetic antioxidants. The highest levels of fatty acids in the bark and seeds were those of linoleic acid, while the lowest were those of γ-linolenic and α-linolenic acids in both parts [31].

3.3. Correlation Analysis Between Traits

The correlation analysis (Table 4) showed a strong positive relationship (0.435) between phenol content and altitude above sea level and a strong negative relationship (−0.425) with soil EC. Additionally, there was a strong negative relationship (−0.544) between clay content and IC50 and a strong positive relationship (0.482) with anthocyanins. A strong positive relationship was also found between TSS/TA and silt (0.507), sand (0.501), soil pH (0.527), and organic matter (0.541). There was a robust negative relationship (−0.708) between TA and clay, a strong positive relationship (0.511) with sand, and a strong negative relationship (−0.451) with organic matter. Different results have been reported regarding the effect of altitude on phenol and antioxidant content. Some studies indicated an increase, others indicated a decrease, and some showed no effect [29,32,33]. Medda et al. [2] reported that altitude has a varying impact on the phenolic content and antioxidant levels in different parts of myrtle. As altitude increased, the levels of phenols and antioxidants in the leaves increased, whereas in the fruit, they decreased. Some studies suggest that genetic factors have a significant influence, more than environmental factors, on the biochemical characteristics of plants [23,24,29]. According to the correlation results (Table 4), the levels of phenols and proteins increased with altitude, which may be one of the mechanisms by which the plant adapts to adverse environmental factors such as high light intensity and ultraviolet radiation [26]. Depending on whether leaves or fruits are the primary targets, selecting specific altitudinal ranges for cultivation may optimize the desired biochemical traits. It has been established that environmental factors can influence the biosynthesis, accumulation, and qualitative composition of phenolic compounds in various plant organs. The increase in the concentration of phenolic compounds under biotic and abiotic stress is due to the PAL gene’s enhanced expression and the PAL enzyme’s activity, which provides a substrate for other reactions [9]. An assessment of the impact of environmental factors on phenolic compounds, tannins, and anthocyanins in 22 cultivars in Italy showed that high temperatures negatively affect phenolic compounds. Anthocyanin content increases with elevation but decreases with rising temperatures. This reduction may be due to lower expression of the genes responsible for anthocyanin production or the degradation of anthocyanins. Additionally, the levels of anthocyanins and tannins positively correlated with rainfall, while total phenols remained unaffected. Water and light availability had a more significant impact on the fruit’s tannin content than temperature [9]. Overall, the concentration of secondary metabolites may serve as a genotypic marker for identifying the origin of cultivars or as an indicator of quality. For example, in kiwi, the level of phenolic compounds can indicate the specific growth site among five locations in China. Besides climate, other abiotic factors may also affect the content of secondary metabolites [34]. Soil is a complex physical, chemical, and biological environment, and various factors influence the relationship between soil, water, and plants [35]. Since roots are the primary agents for absorbing external materials into the plant system, soil edaphic conditions are crucial in producing biochemical compounds and metabolites [30,36]. Ogundola et al. [37] stated that soil texture significantly impacts the biochemical and phytochemical composition of Solanum nigrum, with the highest levels of tannins, flavonoids, anthocyanins, and antioxidant activity measured in plants grown in silty clay loam soils. They also noted that the increase in biochemical and phytochemical compounds in silty clay loam soils may be attributed to adequate moisture retention, which is essential for biochemical and phytochemical functions. Myrtle naturally grows in sandy loam soil with high organic matter, as shown in Table 1 and our previous study [38].

4. Conclusions

The present research highlights the considerable diversity in the morphology and biochemistry of myrtle fruit populations in southwestern Iran. It also emphasizes the influence of genotypes and environmental factors, such as altitude and soil conditions, on fruit biochemical composition, offering valuable insights for selecting suitable cultivation areas. The studied populations demonstrated high levels of phenolic compounds and antioxidant activity, with the SF population showing more significant antioxidant levels. Myrtle fruits hold great promise as a horticultural crop and a natural alternative to synthetic antioxidants, offering potential applications in medicine and fresh consumption. This research also provides a basis for further breeding research in these areas.

Author Contributions

Conceptualization, A.K. and N.S.G.; methodology, D.S.; investigation, D.S.; writing—original draft preparation, D.S.; writing—review and editing, A.K. and N.S.G. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by Shiraz University (Fund NO: 96GCU1M154198).

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors on request.

Conflicts of Interest

The authors declare no conflicts of interest.

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Horticulturae 11 00233 g001
Figure 1. The fruits of myrtle are (a) black or (b) white. The black fruit is more common and has recently gained attention due to its higher antioxidant properties, while the white fruit is rare. The ripening of the fruits occurs in autumn, between October and November (photos: Donya Shahbazian).
Figure 1. The fruits of myrtle are (a) black or (b) white. The black fruit is more common and has recently gained attention due to its higher antioxidant properties, while the white fruit is rare. The ripening of the fruits occurs in autumn, between October and November (photos: Donya Shahbazian).
Horticulturae 11 00233 g001
Table 1. Collection site, soil, and geographical characteristics of myrtle populations from southern Iran.
Table 1. Collection site, soil, and geographical characteristics of myrtle populations from southern Iran.
NO.Accession NameCollection SiteLatitudeLongitudeAltitude (m)ClaySiltSandOrganic Matter (%)pHEC
1ZFZanjyran, Firozabad, Fars, Iran29°03′38″ N52°38′33″ E16975.464.6302.187.431.059
2JFJuddehkuhmareh, Firozabad, Fars, Iran29°06′37″ N52°33′29″ E15707.43854.62.317.110.71
3KHKhergheh, Firozabad, Fars, Iran28°54′22″ N52°22′22″ E149711.96890.41.157.621.1
4KAKavar, Fars, Iran29°07′42″ N53°35′31″ E15257.952864.042.627.351.14
5SMSimakan, Jahrom, Fars, Iran28°41′32″ N52°57′42″ E134413.42.664.062.457.121.05
6ATAtashkadeh, Fars, Iran28°53′23″ N52°32′31″ E14781.961088.041.147.421.5
7SFSarvegarm, Fasa, Fars, Iran29°18′05″ N53°23′09″ E17435.963064.041.677.281.5
8BNBaghnari, Noorabad mamasani, Fars, Iran30°11′10″ N51°47′58″ E12937.962072.042.057.340.97
The populations used, with their abbreviations, were Zanjiran (ZF), Kouhmareh Road (JK), Tang Kherqeh (KH), Kavar (KA), Simkan (SM), Atashkadeh (AT), Sarvegarm (SF), and Baghnari (BN).
Table 2. Morphological characteristics of myrtle fruits in Fars myrtle populations. The table presents the average fruit characteristics derived from the 20 sampled fruits from each individual.
Table 2. Morphological characteristics of myrtle fruits in Fars myrtle populations. The table presents the average fruit characteristics derived from the 20 sampled fruits from each individual.
RegionFruit Length (mm)Fruit
Diameter (mm)		Length/
Diameter Ratio		Seed Length (mm)Seed Diameter (mm)Fruit Weight (g)Pulp Weight (g)Seed Weight (g)NO. Seeds
BN5.85 g5.12 d1.13 e3.22 a1.11 a1.72 g1.51 f0.81 h1.67 f
KA7.47 c5.80 bcd1.28 a2.47 e0.82 e2.17 b1.66 c1.07 b3.66 d
SM6.68 e5.76 bcd1.16 c2.21 f0.81 e1.93 e1.54 f1.05 c3.32 e
JF6.49 f5.72 bcd1.13 e2.53 d0.91 bc2.08 c1.77 b0.93 f3.61 d
ZF6.79 b6.34 ab1.06 f2.71 c0.85 d1.78 f1.61 d0.95 e5.1 a
KH8.29 a6.83 a1.23 b2.23 f0.90 c2.35 a1.58 e1.19 a5.06 a
AT6.66 e5.52 cd1.21 b2.45 e0.92 bc1.93 d1.42 g1.01 d4.64 b
SF7.67 b6.05 bc1.28 a2.93 b0.93 b2.08 c1.82 a0.91 g4.32 c
Mean values with the different letters within a column are significantly different (p < 0.01); LSD test. The populations used, with their abbreviations, were Zanjiran (ZF), Kouhmareh Road (JK), Tang Kherqeh (KH), Kavar (KA), Simkan (SM), Atashkadeh (AT), Sarvegarm (SF), and Baghnari (BN).
Table 3. Biochemical characteristics of myrtle fruits in Fars myrtle populations.
Table 3. Biochemical characteristics of myrtle fruits in Fars myrtle populations.
RegionIC50
(mg dw/mL)		TPC
(mg/100 gfw)		Anthocyanin
(mg/100 gfw)		TSS (%)TA (%)TSS/TA RatioProtein
(mg/g FW)
JF0.87 a820 de102.2 d2.4 a0.1 cd24 a1.33 ab
ZF0.84 a1002 cd218.3 c1.87 bc0.13 bc15 bc1.70 a
AT0.88 a1212 c200.8 c2.15 ab0.17 a13 cd0.60 de
KH0.87 a706 d121.3 d1.033 d0.16 ab10 f0.74 cd
KA0.13 c851 de122 d1.83 c0.12 c16 b1.08 bc
SM0.25 b1218 c53.1 e0.8 d0.07 d12 de1.022 bc
SF0.018 d1600 b311 a1.04 d0.12 c9 ef0.32 ef
BN0.11 c1832 a271.5 b1.84 c0.18 a10 de0.027 f
Mean values with different letters within a column are significantly different (p < 0.01); LSD test. The abbreviations stand for total phenol content (TPC), total soluble solids (TSS), and titratable acidity (TA).
Table 4. Correlation of biochemical characteristics of myrtles and some environmental factors.
Table 4. Correlation of biochemical characteristics of myrtles and some environmental factors.
Altitude (m)1
Clay (Soil)0.3781
Silt (Soil)0.641 **0.191
Sand (Soil)−0.545−0.393−0.97 **1
Organic Matter % (Soil)0.0260.45 *0.3980.2481
pH −0.105−0.103−0.1740.185−0.1711
EC (Soil)0.273−0.3750.2360.261−0.0580.2121
TPC0.435 *−0.036−0.1040.1060.0230.05−0.435 *1
TSS0.396−0.4290.331−0.2060.382−0.348−0.1320.1361
Protein0.751 **0.1610.7 **−0.724 **0.247−0.2590.0730.441 *0.1061
IC50−0.227−0.544 *0.118−0.02−0.042−0.090.335−0.3670.2750.3691
TA−0.069−0.708 **−0.3530.511 *−0.451 *0.2190.1940.2430.26−0.486 *0.1751
TSS/TA0.431−0.0710.507 *0.501 *0.541 *0.527 *−0.329−0.0870.732 **0.445 *0.152−0.4181
Anthocyanin−0.0240.482 *0.150.019−0.0920.291−0.020.2970.412−0.3390.0020.69 **−0.1731
** and * are significantly different (p < 0.01 and p < 0.05 respectively). The abbreviations stand for total phenol content (TPC), total soluble solids (TSS), and titratable acidity (TA).
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Shahbazian, D.; Karami, A.; Gruda, N.S. Biochemical and Morphological Traits of Wild Myrtle Populations for Horticultural Use. Horticulturae 2025, 11, 233. https://doi.org/10.3390/horticulturae11030233

AMA Style

Shahbazian D, Karami A, Gruda NS. Biochemical and Morphological Traits of Wild Myrtle Populations for Horticultural Use. Horticulturae. 2025; 11(3):233. https://doi.org/10.3390/horticulturae11030233

Chicago/Turabian Style

Shahbazian, Donya, Akbar Karami, and Nazim S. Gruda. 2025. "Biochemical and Morphological Traits of Wild Myrtle Populations for Horticultural Use" Horticulturae 11, no. 3: 233. https://doi.org/10.3390/horticulturae11030233

APA Style

Shahbazian, D., Karami, A., & Gruda, N. S. (2025). Biochemical and Morphological Traits of Wild Myrtle Populations for Horticultural Use. Horticulturae, 11(3), 233. https://doi.org/10.3390/horticulturae11030233

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