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Article

Physiological Investigation of Drought Stress Tolerance of ‘W. Murcott’ Mandarin Grafted onto ‘Carrizo’, ‘Sour Orange’, and ‘Volkameriana’ Rootstocks

by
Meral Incesu
,
Berken Cimen
*,
Bilge Yilmaz
,
Turgut Yesiloglu
and
Merve Ilhan
Department of Horticulture, Faculty of Agriculture, University of Cukurova, 01330 Adana, Türkiye
*
Author to whom correspondence should be addressed.
Horticulturae 2025, 11(4), 365; https://doi.org/10.3390/horticulturae11040365
Submission received: 11 February 2025 / Revised: 5 March 2025 / Accepted: 21 March 2025 / Published: 28 March 2025
(This article belongs to the Section Biotic and Abiotic Stress)
Browse Figures
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Abstract

:
This study investigated the effects of rootstock selection and deficit irrigation on the growth, physiological, and photosynthetic performance of young ‘W. Murcott’ mandarin trees. A two-way ANOVA was conducted to evaluate the impact of rootstocks (sour orange, Carrizo citrange, and Volkameriana) and deficit irrigation treatments (40%, 50%, and 70% of field capacity as control) on various plant parameters. Results revealed that rootstock diameter, scion diameter, leaf chlorophyll concentration (Chl), fresh weight, total dry weight, and photosynthetic rate (PN) were significantly influenced by rootstocks and/or deficit irrigation treatments. Deficit irrigation significantly reduced plant height, fresh and dry weights, rootstock diameter, Chl, Fv’/Fm’ (chlorophyll fluorescence), and PN, while scion diameter, stomatal conductance, and water-use efficiency (WUE) remained unaffected. Among rootstocks, sour orange exhibited the highest Chl and Fv’/Fm’ values under water stress, indicating greater drought tolerance, despite showing lower growth compared to Carrizo and Volkameriana. Conversely, Carrizo and Volkameriana rootstocks demonstrated higher fresh and dry weights under optimal irrigation but were more sensitive to water stress. Photosynthetic rate was highest in sour orange-grafted plants under deficit irrigation, while transpiration rates were highest in control plants. These findings suggest that sour orange rootstock may enhance drought resilience by maintaining photosynthetic efficiency and chlorophyll integrity, albeit at the cost of reduced vegetative growth. At the end of this study, it was determined that W. Murcott seedlings grafted onto sour orange rootstock were more tolerant compared to the other two rootstocks.

1. Introduction

Citrus production quantity is one of the highest amounts among the other fruit groups in the world. A total of 24 million tons of production is carried out in the Mediterranean basin, where quality fresh consumption is carried out. The countries producing in the Mediterranean basin, Spain, Italy, Egypt, Greece, and Turkey, are among the important countries in terms of citrus production in the world. Turkey provides 5% of the total Mediterranean basin production and 1% of the world’s total citrus production [1].
Drought stress has begun to have a very severe effect with climate change. Irregular annual rainfall rates and frequent long dry days create problems for plant products produced in the Mediterranean. Citrus fruits are very valuable in this basin because their economic income has a great importance. High-quality products are obtained due to the subtropical climate in the Mediterranean basin. However, irrigation is a very important factor for citrus cultivation, as it is for many fruit crops’ cultivation. Low rainfall due to climate change and very dry periods and floods in certain periods pose a threat to citrus cultivation [2,3,4].
Drought tolerance is one of the most studied and important issues in the countries where citrus fruit is grown in the Mediterranean basin. Drought stress causes decreases in chlorophyll and photosynthetic activities in citrus plants and decreases the fruit yield and quality [4,5,6,7,8,9,10,11,12].
The effects of drought pose threats to growth, yield, membrane integrity, pigment content, osmotic regulation, water relations, and photosynthetic activity. Drought stress negatively affects chlorophyll accumulation. A decrease in chlorophyll content under drought stress conditions is a typical symptom of oxidative stress. The decrease in chlorophyll content in drought occurs as a typical result of pigment photooxidation and chlorophyll degradation [13,14]. It is reported that chlorophyll content decreases with drought stress and the decrease in total chlorophyll content causes the light capture capacity to decrease [15,16]. Drought stress negatively affects photosynthetic activity. Photosynthesis is one of the physiological processes most affected in response to water stress [17]. During drought stress conditions, the rate of photosynthesis may decrease due to stomatal and non-stomatal limitations. One of the first responses to reduce water loss in arid soils is stomatal closure, which also reduces transpiration. However, this process limits the entry of CO2 into mesophyll cells for photosynthesis [18,19,20].
Under mild water stress, stomatal limitation is the main cause of decreased photosynthesis. Under severe drought stress, photosynthesis is reduced in some plants due to biochemical inhibition and metabolic limitations (non-stomatal) [13]. Hue et al. [14] reported that the Fv’/Fm’ of seedlings decreased gradually with the deepening of drought degree, indicating that drought stress reduced the electron transport capacity and primary photochemical activity of PSII and the adverse effects of excessive excitation energy accumulation on photosynthesis. The more Fv’/Fm’ decreased, the higher the inhibition degree was, indicating the more severe damage, which was also the manifestation of the loss of the photosynthetic membrane function of PSII.
Although citrus fruits can be propagated by seeds, cuttings, or other vegetative methods, they are planted using rootstocks. There are basically two reasons for using rootstock. The first is to provide resistance to soil-borne diseases, vector insect-borne diseases or pests, extreme cold or temperatures, poor quality soils, poor quality or inadequate water conditions. The second is to obtain higher yield and quality from the grafted variety [21].
The response of different citrus rootstocks to drought varies depending on the dose of drought stress applied, the genetic structure of the rootstock, the variety it is grafted on, and environmental factors [21,22,23,24]. Grafting scions on abiotic stress-tolerant rootstocks seem a promising tool for facing drought stress effects in plants [25]. Citrus rootstocks have a different strategy to supply the scion with water and nutrients [7,26]. Therefore, a proper rootstock may reduce the adverse effects of environmental stresses on the scion, increasing its resistance to drought conditions [27].
The Cukurova region is one of the most important citrus production areas in Turkey. The recent drought stress has been causing problems in citrus production. Due to climate change, the orchards have been irrigated even in the winter months due to insufficient rainfall. Producers are looking for rootstocks that are more tolerant to drought stress. Due to the high quality and marketability of the W. Murcott mandarin, the drought stress tolerance of sour orange, Volkameriana, and Carrizo citrange, which are widely used in Cukurova, was examined to determine the most drought-tolerant rootstock [28]. In this context, this study was carried out to determine the responses of ‘W. Murcott’ mandarin grafted onto sour orange, Volkameriana, and Carrizo citrange to drought and to decide which rootstock can be used in future drought stress.

2. Materials and Methods

2.1. Plant Material, Drought Treatment, and Determining Field Capacity of Soil

This study was conducted at Cukurova University, Department of Horticulture, in 2021. W. Murcott (Citrus reticulata) scions budded on local sour orange (Citrus aurantium L.), Carrizo citrange (Citrus sinensis [L.] Osb. × Poncirus trifoliata [L.] Raf.), and Volkameriana (Citrus volkameriana) were used as plant material. Seeds were germinated in the dark at 22 °C in plastic trays with sterilized 1:1 peat/soil. After germination, the seedlings were grown for 8 months in the greenhouse. Uniform seedlings were selected and surface sterilized (20% NaClO for 20 min) then transferred into pots for scion budding. After budding, seedlings were grown in a modified Hoagland nutrient solution for citrus for 8 months. Just before starting the treatments, the plants were transferred to 11 L pots that were filled with soil and transferred to a plant growth chamber. Until stress was applied, all plants were irrigated with a solution of the following composition: 1.25 mM KNO3, 0.625 mM KH2PO4, 2.00 mM MgSO4, 2.00 mM Ca(NO3)2, EDTA-Fe (125 μM), 25.0 μM H3BO3, 2.00 μM MnSO4, 2.00 μM ZnSO4, 0.50 μM CuSO4, 0.065 μM (NH4)6Mo7O24 for 2 months in order to ensure plant adaptation to growth chamber conditions. The pH of the nutrient solution was adjusted to 6.0–6.5 with nitric acid. The plants were subjected to three levels of control, 50% and 40% drought stress. Plants were exposed to deficit irrigation treatments for two months. Plants in the growth chamber experienced 65% relative humidity, 900 ± 25 μmol m−2s−1 photosynthetic photon flux density (PPFD) at the top of the plant canopy, and a photoperiod of 16 h day/8 h night with a 26 °C day and 20 °C night air temperature. The rootstocks, whose drought tolerance levels will be determined, were grown in three different water levels. By calculating the field capacity (FC), drought stress was applied by keeping the weight of control plants (70% of the FC water content), moderate drought stress plants (50% of the FC water content), and drought stress plants (40% of the FC water content) constant. Field capacity values were determined by calculating the volumetric water content values in each soil sample after applying 0.33 bar pressure to the soil samples in the pressure plate device [29].

2.2. Plant Growth Measurements

At the beginning of the experiment, fresh weight (g) and plant height (cm) were recorded for each replicant. After two months of deficit irrigation treatment, those variables were recorded again. The differences between the latter and initial values were calculated to assess plant growth during the experimental period. After leaf chlorophyll concentration and leaf gas exchange measurements, the plants were harvested for dry mass (DM) measurements for this purpose; samples were dried at 72 °C for 48 h using a thermo-ventilated oven.
Rootstock diameter (mm) was measured in mm with a caliper, 5 cm below the graft level of the plants in the experiment. Measurements were made at the beginning and at the end of the experiment, and the difference between the two measurements and rootstock growth rate was found. Scion diameter (mm) was measured in mm with a caliper, 5 cm above the graft level of the plants in the experiment.

2.3. Gas Exchange Measurements and Chlorophyll Concentration

At the end of the experiment, ten measurements were taken from each replicate of plants for each drought treatment in the greenhouse. Transpiration rate (E) (mmol m−2s−1), stomatal conductance (gS) [(mmol H2O m−2s−1)], photosynthetic rate (PN) [µmol(CO2) m−2s−1], and substomatal CO2 concentration (ppm) were measured at the end of the experiment using a LI-COR LI-6400 (LI-COR Inc., Lincoln, NE, USA) portable photosynthesis system. All gas exchange measurements were taken on attached fully expanded young leaves. Measurements were recorded in the morning from 08:00 to 10:00 h to avoid high temperatures and low humidity in the afternoon. The average saturation irradiance was 900 µmol m−2s−1 and leaf temperature ranged from 28 to 30 °C. Leaf chlorophyll concentration was estimated using a portable SPAD meter (Minolta Inc., Osaka, Japan). Chlorophyll fluorescence parameter (Fv’/Fm’) was measured with a portable fluorimeter (FluorPen FP100, Photon System Instruments Ltd., Drasov, Czech Republic) in light-adapted stage of the fully developed leaf of each plant. During the gas exchange measurements, leaf temperature ranged between 24 and 26 °C and the relative humidity was 50% where PFD was detected as 800–850 μmol m−2 s−1.

2.4. Experimental Design and Data Analysis

The experiment was arranged as 3 × 3 × 10, three treatments, three rootstocks, and 10 replicates, respectively, in a complete randomized factorial design. Data were subjected to a two-way analysis of variance (ANOVA). Significant differences between means were calculated by using Tukey’s multiple range test at a significance level of p ≤ 0.05. The correlation coefficients between all measured parameters were also calculated. All statistical analyses were performed with R (v4.4.0), and RStudio (v2024.04.1) was used for data visualization.

3. Results

3.1. Plant Growth, Chlorophyll Concentration, and Chlorophyll Fluorescence

Rootstock (R), deficit irrigation (DI) treatment effects, and R × DI interaction effect were subjected to a two-way ANOVA. The effect of rootstocks on plant height (cm), chlorophyll fluorescence (Fv’/Fm’), transpiration rate (E), stomatal conductance, and leaf photosynthetic water-use efficiency (WUE) were not statistically significant according to a two-way ANOVA conducted. On the contrary, rootstock diameter (cm), scion diameter (cm), leaf chlorophyll concentration (Chl), fresh weight (g), total dry weight (g), and photosynthetic rate (PN) variables were significantly affected by rootstocks and/or deficit irrigation treatments (Table 1). Deficit irrigation treatments significantly affected plant height (cm), rootstock diameter (cm), Chl, fresh weight (g), Fv’/Fm’, fresh weight (g), total dry weight (g), PN and E of W. Murcott mandarin grafted onto three rootstocks. Scion diameter, stomatal conductance, and WUE were not significantly affected by the deficit irrigation treatments. In terms of rootstock × deficit irrigation treatments’ interaction effects, all variables except stem diameter were found to be statistically insignificant (Table 1).
The effects of deficit irrigation on plant fresh and dry weight, plant height, stem diameter, scion diameter, leaf Chl concentration, Fv’/Fm’ of W. Murcott mandarin grafted onto different rootstocks are presented in Table 2. The effect of rootstocks on fresh weight (g) of W. Murcott mandarin grafted on different rootstocks was statistically significant. The highest fresh weight amount was detected in plants grafted on Volkameriana (163.60 g) and Carrizo citrange (174.80 g). The effect of deficit irrigation treatment on fresh weight (g) was statistically significant according to a two-way ANOVA conducted. The highest fresh weight was determined in control plants with 186.40 g, followed by a 50% deficit irrigation treatment (153.73 g), whereas the lowest fresh weight was recorded in 40% plants as 153.73 g. The effect of the rootstock × deficit irrigation interaction effect on fresh weight was not statistically significant (Table 2). In terms of plant dry weight (g), a significant rootstock effect was determined according to a two-way ANOVA conducted. The highest dry weight was found in plants grafted on- to Carrizo citrange (96.80 g) and Volkameriana (83.07 g), whereas the lowest was in plants grafted onto sour orange rootstock (53.07 g). The effect of 40%, 50%, and 70% (control) treatments on dry weight (g) was statistically significant. The highest dry weight was determined in control plants with 96.00 g, followed by 50% deficit irrigation as 77.60 g. On the contrary, the rootstock × deficit irrigation interaction effect on dry weight was insignificant (Table 2).
The effect of rootstocks on plant height was not significant according to a two-way ANOVA conducted. The effect of deficit irrigation amounts on plant height was statistically significant. The highest plant height was determined in control plants (9.20 cm), while the plant heights at 50% and 40% irrigation doses were 6.13 cm and 5.17 cm, respectively. The interaction effect of rootstock × irrigation was not statistically significant according to a two-way ANOVA conducted (Table 2).
In terms of rootstock diameter, the lowest diameter was recorded in the plants grafted on Carrizo citrange (0.48 mm), whereas rootstock diameters of sour orange and Volkameriana were determined as 0.79 mm and 0.81 mm, respectively. In addition, deficit irrigation significantly affected rootstock diameter. The highest rootstock diameter was determined in the control plants (0.98 mm), whereas it was determined as 0.47 mm in the 40% irrigation treatment and 0.64 mm in the 50% irrigation treatment. Rootstock × deficit irrigation interaction effect was statistically significant in terms of rootstock diameter. The highest rootstock diameter was found in the control plants grafted on Volkameriana (1.43 mm), and the lowest was found in the 40% deficit irrigation treatment (0.29 mm) grafted on Carrizo citrange (Table 3). In addition, rootstocks significantly affected scion diameter growth. The lowest scion diameter was recorded in plants grafted on Carrizo citrange (0.26 mm) and sour orange (0.32 mm), whereas it the highest and 0.50 mm in plants grafted on Volkameriana rootstock. The effects of deficit irrigation main effect and rootstock × deficit irrigation interaction effect on scion diameter were not statistically significant according to a two-way ANOVA conducted (Table 3).
Significant main effects were determined on leaf chlorophyll concentration and leaf chlorophyll fluorescence variables of W. Murcott mandarin grafted onto different rootstocks under deficit irrigation treatments (Table 3). Rootstocks significantly affected leaf Chl concentration of W. Murcott mandarin grafted on different rootstocks. The highest Chl concentration was determined in the leaves of plants grafted on sour orange (54.18) whereas it was the lowest in the leaves of plants grafted onto Carrizo and Volkameriana rootstocks (45.93 and 48.62, respectively). In addition, there was a significant deficit irrigation effect on the Chl concentration of the leaves of plants grafted onto different rootstocks. The highest Chl concentration was determined in control plants as 56.07. In terms of leaf Chl fluorescence (Fv’/Fm’), a significant deficit irrigation effect was calculated according to a two-way ANOVA conducted. The highest Fv’/Fm’ was determined in control plants as 0.62, followed by 50% deficit irrigation treatment as 0.55, and the lowest Fv’/Fm’ was determined in the leaves of plants treated with 40% deficit irrigation (Table 3).

3.2. Leaf Gas Exchange Measurements

In the deficit irrigated leaves of W. Murcott, the photosynthetic rate (PN) was inhibited on all rootstocks. A two-way ANOVA indicated significant (p ≤ 0.05) rootstock and deficit irrigation treatment effects on PN (Table 4). ‘W. Murcott’ grafted on sour orange had higher PN than those on other rootstocks under deficit irrigation conditions. The lowest PN values were recorded in plants grafted on Carrizo citrange. The effect of 40%, 50%, and 70% (control) irrigation treatments on PN was statistically significant according to a two-way ANOVA conducted. The highest PN was determined in the control plants (6.70), and in 40% and 50% deficit irrigation treatments it was determined as 5.35 and 5.67, respectively. There was also a significant difference in the deficit irrigation treatment in terms of E of W. Murcott mandarin grafted onto different rootstocks. Leaves of the shoots of control plants had the highest E values. There were no significant main and interaction effects on stomatal conductance and the gSw values varied from 30.00 to 48.33 mmol m−2s−1. Similarly, rootstocks, deficit irrigation, and their interaction effects were not statistically significant on leaf photosynthetic water-use efficiency. The WUE value ranged from 2.85 to 3.47 (Table 4).

3.3. Correlation Coefficients Analysis

Significant correlations between investigated parameters were determined regarding investigated variables of W. Murcott mandarin grafted onto Carrizo, sour orange, and Volkameriana rootstocks under drought stress (Figure 1). A correlation heatmap showed that the correlations between Chl content and PN (0.72), E and gS (0.56) were significant. Also, high correlation coefficients were calculated between plant fresh and dry weight (0.83) and transpiration rate and leaf photosynthetic water-use efficiency.
Therefore, regression analyses were performed between leaf gas exchange measurements concerning high r2 values (p = 0.05). The regression analysis confirmed that the PN rate was increased by the high Chl content in the leaves (Figure 2a). In addition, a strong relationship was determined between stomatal conductance and transpiration rate (Figure 2b).

4. Discussion

In this work, we described how rootstock affected the growth and the photosynthetic performance of leaves from young ‘W. Murcott’ trees grown under deficit irrigation conditions. Citrus production is being carried out using rootstocks. The drought tolerance of rootstock/scion combinations differs from each other. Grafting scions on abiotic stress-tolerant rootstocks seems a promising tool for facing drought stress effects in plants [11]. Drought affects plant growth and development, reducing the growth rate and the biomass accumulation and ultimately crop yield [27]. In this study, rootstock diameter (cm), fresh and dry weight (g) were statistically affected by both the rootstock and the deficit irrigation treatment. Comparing rootstocks, it was determined that the lowest plant development was in those grafted onto sour orange. As the irrigation amount decreased, the rootstock diameter, fresh and dry weights decreased. While the plants grafted on sour orange were found to be the lowest in terms of dry weight, the highest dry weight in the dose application was determined in the control plants. When fresh weight and dry weights were compared, it was determined that sour orange rootstock was more affected by drought than the other two rootstocks. Carrizo was the least affected rootstock according to the dry weight and fresh weight.
A deficit irrigation treatment was applied for 2 months, during which control plants were irrigated with 70% of field capacity, while others were irrigated with 40% and 50%. The 2-month period caused statistically significant differences in the fresh and dry weights of plants in both the rootstock and the deficit irrigation treatments. At the end of the 2-month period, the rootstock diameter was affected more than the scion diameter. While the interaction of rootstock, deficit irrigation treatments, and rootstock deficit irrigation treatments was significant on rootstock diameter, only the effect of rootstock was statistically significant on scion diameter. It is thought that the reason for this is that rootstocks increased the scion diameter at different amounts in the 8-month period from the time the plants were grafted until the period when the deficit irrigation treatments were applied. Rootstock/scion combinations affect the development of the scion on rootstocks at different levels. In drought stress, different responses were observed with drought together with the rootstock/scion effect. For instance, Korkmaz et al. [12], in their study comparing Flying dragon, Carrizo, and sour orange rootstocks, reported that Flying dragon rootstock was more tolerant than Carrizo and sour orange. Romero et al. [5] claimed that ‘Cleopatra’ mandarin rootstock has a higher tolerance to water stress than ‘Carrizo’ citrange, and is a better rootstock for field-grown Clemenules mandarin. Magalhaes Filho et al. [30] reported that Valencia orange grafted onto Rangpur lime was more tolerant to drought than those grafted onto Poncirus trifoliata orange.
Citrus rootstocks showed different responses to drought in rootstock/scion combinations. In our study, the citrus rootstock commonly used in the Cukurova region fell behind the other two rootstocks in plant growth parameters under drought stress. Kumar et al. [31] found that sour orange root systems exhibit a balanced set of traits, unlike Carrizo, which showed less desirable root characteristics. Sour orange develops deep tap roots, but its lateral root growth is less extensive compared to other citrus varieties like Rough lemon, sweet orange, or grapefruit. When the taproot is cut during transplanting, it typically branches out into a small cluster. Sour orange roots tend to be cone-shaped, featuring strong central roots and a monopodial structure, with weaker upper roots and obliquely descending lateral roots. The overall root system’s composition of fibrous roots, laterals, and tap roots varies based on the rootstock cultivar and environmental conditions. Numerous factors, such as the scion variety, environment, and soil conditions, influence root distribution. This explains the inconsistencies in root system descriptions from different researchers. Furthermore, Rodriguez-Ramir et al. [7] asserted that rootstock traits significantly affect drought response through variations in root distribution, water uptake, and hydraulic conductivity, making rootstock selection crucial for managing citrus plants under water-deficient conditions.
At the end of the 2-month period in which the deficit irrigation treatment was applied, the effect of both rootstock and restricted water application on leaf chlorophyll concentration was found to be significant. It was determined that restricted water application played a very effective role in chlorophyll formation. Numerous studies have shown that drought conditions lead to a decrease in chlorophyll content, and the ability to maintain chlorophyll levels is associated with greater drought tolerance [32]. Perez-Perez et al. [33] reported in their drought study on the Fino 49 lemon variety that the total chlorophyll content decreased in drought-stressed plants. Kacar et al. [34] stated that drought stress negatively affects chlorophyll synthesis. Monteoliva et al. [32] found that the water deficit caused by drought triggers the breakdown of the thylakoid membrane in chloroplasts in most plant species, leading to a decline in chlorophyll and other photosynthetic pigments. This stress results in reduced photosynthetic rates, smaller leaf areas, and ultimately lower yields. However, not all plants experience a decrease in chlorophyll content under drought conditions. Certain drought-tolerant grasses, as well as soybean and potato, have been observed to maintain their chlorophyll levels during drought. The capacity to preserve chlorophyll content can vary based on the plant’s genotype, the duration of the stress, and its intensity. Generally, plants that retain higher chlorophyll levels under drought conditions are more efficient at utilizing light energy, which is a sign of greater drought tolerance. Consistent with all this information, in this study it was determined that drought stress caused lightening in leaf color and decreases in chlorophyll value.
Fv’/Fm’ was affected by deficit irrigation and the highest Fv’/Fm’ was determined in the control plants. It has been determined that the deficit irrigation treatment is effective on the Fv’/Fm’ ratio, just as it is on the chlorophyll concentration. Control plants exhibited approximately 1.5 times higher chlorophyll fluorescence yield compared to the 40% application. These data have shown us how significantly water affects plant health, even during the seedling stage.
Guo et al. [35] stated that chlorophyll fluorescence kinetic parameters reveal details about how leaves absorb, convert, transfer, and distribute light energy. Among these parameters, the maximum photochemical quantum yield (Fv/Fm) indicates the highest efficiency of light energy conversion in the reaction center of photosystem II (PSII). As a result, indicators of drought tolerance have been developed to assess how well different plant genotypes adapt to drought conditions. Fv/Fm shows a positive correlation with the severity of drought, making it a useful tool for analyzing physiological changes in plants under drought stress. They reported that Fv’/Fm’ activity decreased with water stress in Sutil lime trees grafted onto Cleopatra mandarin [36]. In this study, control plants gave the highest 40% irrigation regime and the lowest Fv/Fm amount.
PN was found to be higher in control plants than in limited water applications, and the highest photosynthesis was detected in plants grafted onto sour orange rootstock. Vu and Yelenosky [37], on the Valencia orange; Chen et al. [38], in the Satsuma mandarin; Moran et al. [39], in peas; and Erismann et al. [40] reported that the photosynthesis rate decreased with drought stress in the Valencia orange. With the pause of photosynthesis under drought stress, photosynthesis occurs in two ways: control by stomata and control by factors outside stomata [41]. When the plant closes its stomata to prevent water loss, the intake of CO2 required for photosynthesis is prevented. In addition, the rate of transpiration is adjusted by the density of the stomata and the order in which the stomata open and close [42]. The highest transpiration rate in plants grafted onto Carrizo citrange was detected in the control plants. In other treatments, the control plants had the highest transpiration amount, but it was not found to be statistically significant.
When all the data are taken into account, they demonstrate how crucial the amount of water provided to plants is for their development. The uneven distribution of rainfall due to climate change shows that when plants cannot receive the necessary amount of water at the required time, it negatively affects seedling growth. The decrease in rainfall in Cukurova, a region where citrus farming is intensive, impacts production in this area. The performance of the W. Murcott variety grafted onto three commonly used rootstocks in Cukurova sour orange, Carrizo, and Volkameriana has been evaluated. Among these, the sour orange rootstock grafted with W. Murcott was the most affected by water restriction in terms of plant growth. However, it outperformed the other two rootstocks in terms of Fv/Fm and leaf chlorophyll concentration. This experiment was conducted under pot conditions. Field trials should also be carried out to assess the drought performance of these three rootstocks. The fact that the sour orange rootstock performed better in terms of chlorophyll and Fv/Fm compared to the other two rootstocks suggests that its performance should be evaluated over a longer stress period. Although plant growth was lower than the other two rootstocks, the higher chlorophyll and Fv/Fm levels indicate promising drought tolerance. Perhaps the smaller size of the plant grafted onto the sour orange rootstock is a protective mechanism against water scarcity, as it avoids excessive growth. This could be due to reduced stomatal conductance under water deficit irrigation.

5. Conclusions

This study highlights the significant impact of rootstock selection and deficit irrigation on the growth, photosynthetic performance, and drought tolerance of young ‘W. Murcott’ citrus trees. The findings demonstrate that rootstocks play a critical role in determining the physiological and developmental responses of citrus plants under water stress conditions. Among the rootstocks evaluated, sour orange exhibited the lowest plant growth under deficit irrigation but outperformed Carrizo and Volkameriana in terms of chlorophyll concentration and Fv/Fm values, indicating a potential mechanism for drought tolerance. This suggests that while sour orange may limit vegetative growth under water scarcity, it prioritizes maintaining photosynthetic efficiency and chlorophyll integrity, which are crucial for survival under stress.
At the end of this study, it was determined that W. Murcott seedlings grafted onto sour orange rootstock were more tolerant compared to the other two rootstocks. However, this study was conducted under pot conditions. It is necessary to carry out this study under field conditions as well.

Author Contributions

Conceptualization, M.I. (Meral Incesu) and B.C.; Methodology, M.I. (Meral Incesu); Investigation, M.I. (Merve Ilhan); Data Curation, B.C.; Writing—Original Draft Preparation, B.C.; Writing—Review and Editing, T.Y., B.C. and B.Y.; Visualization, B.C.; Supervision, M.I. (Meral Incesu). All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Research Fund of the Cukurova University. Project Number: FYL-2022-14490.

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. FAO. FAOSTAT-Agriculture Database (2022). Available online: http://faostat.fao.org/en/#data/QCL (accessed on 5 January 2025).
  2. Gimeno, J.; Gadea, J.; Forment, J.; Pérez-Valle, J.; Santiago, J.; Martínez-Godoy, M.A.; Yenush, L.; Bellés, J.M.; Brumós, J.; Colmenero-Flores, J.M.; et al. Shared and novel molecular responses of mandarin to drought. Plant Mol. Biol. 2009, 70, 403–420. [Google Scholar] [CrossRef] [PubMed]
  3. Pandey, P.; Irulappan, V.; Bagavathiannan, M.V.; Senthil-Kumar, M. Impact of combined abiotic and biotic stresses on plant growth and avenues for crop improvement by exploiting physio-morphological traits. Front. Plant Sci. 2017, 8, 537. [Google Scholar] [CrossRef]
  4. Balfagón, D.; Zandalinas, S.I.; dos Reis de Oliveira, T.; Santa-Catarina, C.; Gómez-Cadenas, A.G. Reduction of heat stress pressure and activation of photosystem II repairing system are crucial for citrus tolerance to multiple abiotic stress combination. Physiol. Plant. 2022, 174, e13809. [Google Scholar] [PubMed]
  5. Romero, P.; Navarro, J.M.; Perez-Perez, J.; Garcia-Sanchez, F.; Gomez-Gomez, A.; Porras, I.; Martinez, V.; Botia, P. Deficit irrigation and rootstock: Their effects on water relations, vegetative development, yield, fruit quality and mineral nutrition of Clemenules mandarin. Tree Physiol. 2006, 26, 1537–1548. [Google Scholar]
  6. Garcıa-Sanchez, F.; Syvertsen, P.J.; Gimeno, V.; Botia, P.; Perez, G. Responses to Flooding and Drought Stres by Two Citrus Rootstock Seedlings with Different Water-Use Efficency. Physiol. Plant. 2007, 130, 532–542. [Google Scholar]
  7. Rodriguez-Gamir, J.; Primo-Millo, E.; Forner, J.B.; Forner-Giner, M.A. Citrus rootstock responses to water stress. Sci. Hortic. 2010, 126, 95–102. [Google Scholar]
  8. García-Tejero Iván, F.; Víctor, H.; Durán-Zuazo, J.; Muriel-Fernández, L.; Jiménez-Bocanegra, J.A. Linking canopy temperature and trunk diameter fluctuations with other physiological water status tools for water stress management in citrus orchards. Funct. Plant Biol. 2011, 38, 106–117. [Google Scholar] [CrossRef]
  9. Cerçi, S. Effects of Drought Stress on Some Photosynthetic Parameters and Plant Nutrient Concentrations in Different Citrus Rootstocks. Master’s Thesis, Institute of Science, Çukurova University, Adana, Turkey, 2012; 104p. [Google Scholar]
  10. Zandalinas, S.I.; Rivero, R.M.; Martínez, V.; Gómez-Cadenas, A.; Arbona, V. Tolerance of citrus plants to the combination of high temperatures and drought is associated to the increase in transpiration modulated by a reduction in abscisic acid levels. BMC Plant Biol. 2016, 16, 105. [Google Scholar] [CrossRef]
  11. Souza, J.D.; Silva, D.A.E.M.; Filho, M.A.C.; Morillon, R.; Bonatto, D.; Micheli, F.; Gesteria, A.D.S. Different adaptation strategies of two citrus scion/rootstock combinations in response to drought stress. PLoS ONE 2017, 12, e0177993. [Google Scholar]
  12. Korkmaz, N.; Aşkın, A.; Altunlu, H.; Polat, M.; Okatan, V.; Kahramanoglu, I. The effects of melatonin application on the drought stress of different citrus rootstocks. Turk. J. Agric. For. 2022, 46, 585–600. [Google Scholar] [CrossRef]
  13. Anjum, S.A.; Xie, X.Y.; Wang, L.C.; Saleem, M.F.; Chen, M.; Wang, L. Morphological, physiological and biochemical responses of plants to drought stress. Afr. J. Agric. Res. 2011, 6, 2026–2032. [Google Scholar]
  14. Hu, F.; Zhang, Y.; Guo, J. Effects of drought stress on photosynthetic physiological characteristics, leaf microstructure, and related gene expression of yellow horn. Plant Signal. Behav. 2023, 18, e2215025. [Google Scholar] [CrossRef]
  15. Mafakheri, A.; Siosemardeh, A.; Bahramnejad, B.; Struik, P.C.; Sohrabi, E. Effect of drought stress on yield, proline and chlorophyll contents in three chickpea cultivars. Aust. J. Crop Sci. 2010, 4, 580–585. [Google Scholar]
  16. Wu, X.; Yuan, J.; Luo, A.; Chen, Y.; Fan, Y. Drought stress and rewatering increase secondary metabolites and enzyme activity in dendrobium moniliforme. Ind. Crops Prod. 2016, 94, 385–393. [Google Scholar] [CrossRef]
  17. Pinheiro, C.; Chaves, M. Photosynthesis and drought: Can we make metabolic connections from available data? J. Exp. Bot. 2011, 62, 869–882. [Google Scholar] [CrossRef]
  18. Cornic, G. Drought stress inhibits photosynthesis by decreasing stomatal aperture—Not by affecting ATP synthesis. Trends Plant Sci. 2000, 5, 187–188. [Google Scholar]
  19. Grassi, G.; Magnani, F. Stomatal, mesophyll conductance and biochemical limitations to photosynthesis as affected by drought and leaf ontogeny in ash and oak trees. Plant Cell Environ. 2005, 28, 834–849. [Google Scholar] [CrossRef]
  20. Flexas, J.; Bota, J.; Galmes, J.; Medrano, H.; Ribas-Carbó, M. Keeping a Positive Carbon Balance under Adverse Conditions: Responses of Photosynthesis and Respiration to Water Stress. Physiol. Plant. 2006, 127, 343–352. [Google Scholar] [CrossRef]
  21. Ferguson, L.; Sakovich, N.; Roose, M. California Citrus Rootstocks; University of California Cooperative Extension Publication: Berkeley, CA, USA, 1990. [Google Scholar]
  22. von Broembsen. L.A. Citrus Rootstocks—The Choice You Have; S.A. Cooperative Citrus Exchange Ltd.: Pretoria, South Africa, 1985; p. 19. [Google Scholar]
  23. Castle, W.S.; Tucker, D.P.H.; Krezdom, A.H.; Youtsey, C.O. Rootstocks for Florida Citrus; University of Florida Cooperative Extension Service Publication: Gainesville, FL, USA, 1989; p. 41. [Google Scholar]
  24. Diaz-Curti, S.A.; Hernandez, C.; Lopez-Maza, I.; Salazar-Loredo, R.X.; Gonzalez-Sanchez, A.; Drought Tolerance of 27 Citrus Rootstocks Growing in a Nursery. International Society of Citriculture Abstracts. 2004; p. 145. Available online: https://www.ars.usda.gov/research/publications/publication/?seqNo115=163292 (accessed on 5 January 2025).
  25. Gonçalves, L.P.; Alves, T.O.; Martins, C.P.S.; de Sousa, A.O.; dos Santos, I.C.; Pirovani, C.P.; Almeida, A.F.; Filho, M.A.C.; Gesteira, A.S.; Soares Filho, S.; et al. Rootstock-induced physiological and biochemical mechanisms of drought tolerance in sweet orange. Acta Physiol. Plant. 2016, 38, 174. [Google Scholar] [CrossRef]
  26. Santana-Vieira, D.D.S.; Freschi, L.; Almeida, L.A.D.H.; Moraes, D.H.S.D.; Neves, D.M.; Santos, L.M.D.; Neves, D.M.; Santos, L.M.; Bertolde, F.Z.; Soares Filho, W.S.; et al. Survival strategies of citrus rootstocks subjected to drought. Sci. Rep. 2016, 6, 38775. [Google Scholar] [CrossRef]
  27. Sousa, A.D.O.; Silva, D.A.E.M.; Filho, M.A.C.; Costa, M.G.C.; Filho, W.D.S.S.; Micheli, F.; Maserti, B.; Gesteria, A.D.S. Metabolic responses to drought stress and rehydration in leaves and roots of three citrus scion/rootstock combinations. Sci. Hortic. 2022, 292, 110490. [Google Scholar] [CrossRef]
  28. Cimen, B.; Yesiloglu, T. Rootstock Breeding for Abiotic Stress Tolerance in Citrus; InTech: Houston, TX, USA, 2016. [Google Scholar]
  29. Klute, A. Methods of Soil Analysis. Part 1: Physical and Mineralogical Methods, 2nd ed.; American Society of Agronomy and Soil Science Society of America: Madison, WI, USA, 1986. [Google Scholar]
  30. Magalhães Filho, J.R.; Amaral, L.R.; Machado, D.F.S.P.; Medina, C.L.; Machado, E.C. Water deficit, gas exchange and root growth in’ Valencia’ orange tree budded on two rootstocks. Bragantia 2008, 67, 75–82. [Google Scholar] [CrossRef]
  31. Kumar, S.; Awasthi, O.P.; Dubey, A.K.; Pandey, R.; Sharma, V.K.; Mishra, A.K.; Sharma, R.M. Root morphology and the effect of rootstocks on leaf nutrient acquisition of Kinnow mandarin (Citrus nobilis Loureiro × Citrus reticulata Blanco). J. Hortic. Sci. Biotechnol. 2017, 93, 100–106. [Google Scholar] [CrossRef]
  32. Monteoliva, M.I.; Guzzo, M.C.; Posada, G.A. Breeding for drought tolerance by monitoring chlorophyll content. Gene Technol. 2021, 10, 10–35248. [Google Scholar]
  33. Perez-Perez, J.G.; Syvertsen, J.P.; Botia, P.; Garcıa-Sanchez, F. Leaf Water Relations and Net Gas Exchange Responses of Salinized Carrizo citrange Seedlings During Drought Stress and Recovery. Ann. Bot. 2007, 100, 335–345. [Google Scholar] [PubMed]
  34. Kaçar, B.; Katkat, A.V.; Öztürk, Ş. Plant Physiology; Uludag University: Bursa, Turkey, 2002. [Google Scholar]
  35. Guo, C.; Liu, L.; Sun, H.; Wang, N.; Zhang, K.; Zhang, Y.; Zhu, J.; Li, A.; Bai, Z.; Liu, X.; et al. Predicting Fv/Fm and evaluating cotton drought tolerance using hyperspectral and 1D-CNN. Front. Plant Sci. 2022, 13, 1007150. [Google Scholar]
  36. Soto, A.C.; María Sara, M.; Ríos Rojas, M. Gas exchange and fluorescence in ‘sutil’ lime (Citrus aurantifolia Swingle) under different soil moisture levels. Bioagro 2022, 34, 195–206. [Google Scholar] [CrossRef]
  37. Vu, J.C.V.; Yelenosky, G. Biomass and photosynthesis responses of rough lemon (Citrus jambhiri Lush.) to growth regulators. Can. J. Plant Sci. 1988, 68, 261–266. [Google Scholar]
  38. Chen, Z.H.; Zhang, L.C.; Wu, G.L.; Zhang, S.L. Photosynthesis of Citrus Under Water Stres. Acta Agric.-Univ. Zheylangensis 1992, 18, 60–66. [Google Scholar]
  39. Moran, E.F.; Brondizio, E.S.; Mausel, P.; Wu, Y. Integrating Amazonian Vegetation, Land-use and Satellite Data. BioScience 1994, 44, 329–338. [Google Scholar]
  40. Erismann, N.; Machado, E.C.; Sant, M.L.; Tucci, A. Photosynthetic Limitation by CO2 Diffusion in Drought Stresses Orange Leaves on Three Rootstocks. Photosynth. Res. 2008, 96, 163–172. [Google Scholar]
  41. Kutlu, I. Drought Stress in Cereals. Turk. J. Sci. Rev. 2010, 3, 35–41. [Google Scholar]
  42. Kuşvuran, Ş.; Daşgan, H.Y.; Abak, K. Responses of Different Okra Genotypes to Drought Stress. In Proceedings of the VII. Vegetable Farming Symposium, Yalova, Türkiye, 26–29 August 2008; pp. 329–333. [Google Scholar]
Horticulturae 11 00365 g001
Figure 1. Correlation coefficients analysis between investigated variables.
Figure 1. Correlation coefficients analysis between investigated variables.
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Figure 2. Regression coefficients analysis between investigated variables. (a) Leaf Chl concentration vs. Net Photosynthetic rate; (b) Stomatal conductance vs. Transpiration rate.
Figure 2. Regression coefficients analysis between investigated variables. (a) Leaf Chl concentration vs. Net Photosynthetic rate; (b) Stomatal conductance vs. Transpiration rate.
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Table 1. Results of two-way analysis of variance (ANOVA) of rootstock (R) and deficit irrigation (DI) effects and their interaction (R × DI) for the dependent variables considered. Numbers represent F values. * p < 0.05. ns: not significant.
Table 1. Results of two-way analysis of variance (ANOVA) of rootstock (R) and deficit irrigation (DI) effects and their interaction (R × DI) for the dependent variables considered. Numbers represent F values. * p < 0.05. ns: not significant.
Dependent VariableIndependent Variable
RDIR × DI
Plant height (cm)0.57 ns17.80 *0.99 ns
Rootstock diameter (mm)4.87 *9.84 *3.11 *
Scion diameter (mm)7.84 *2.70 ns1.32 ns
SPAD8.58 *16.73 *2.36 ns
Fv’/Fm’0.26 ns31.46 *1.29 ns
Fresh weight (g)11.79 *16.28 *1.22 ns
Total dry weight (g)19.19 *12.89 *0.21 ns
PN10.91 *12.37 *0.92 ns
E2.80 ns3.56 *1.32 ns
gS3.30 ns1.94 ns1.07 ns
WUE0.06 ns0.14 ns0.67 ns
Table 2. Fresh weight (g), dry weight (g), plant height (cm), rootstock diameter (mm) of W. Murcott mandarin grafted onto Carrizo, sour orange, and Volkameriana rootstocks under drought stress. Mean values in the same column with different letters are significantly different according to Tukey’s test (p = 0.05). ns: not significant.
Table 2. Fresh weight (g), dry weight (g), plant height (cm), rootstock diameter (mm) of W. Murcott mandarin grafted onto Carrizo, sour orange, and Volkameriana rootstocks under drought stress. Mean values in the same column with different letters are significantly different according to Tukey’s test (p = 0.05). ns: not significant.
RootstockDIFresh Weight (g)Dry Weight (g)Plant Height (cm)
Carrizo 174.80 a96.80 a7.00
Sour orange 119.60 b53.07 b6.40
Volkameriana 163.60 a83.07 a7.10
40%117.87 c59.33 c5.17 b
50%153.73 b77.60 b6.13 b
Control186.40 a96.00 a9.20 a
Carrizo40%140.8075.605.40
50%171.2097.606.40
Control212.40117.209.20
Sour orange40%98.8037.204.60
50%125.6048.805.80
Control134.4073.208.80
Volkameriana40%114.0065.205.50
50%164.4086.406.20
Control212.4097.609.60
LSD0.05Rootstock24.36614.640ns
Treatment24.36614.6401.431
Interactionnsnsns
Table 3. Rootstock diameter (mm), scion diameter (mm), leaf Chl concentration (SPAD readings), and chlorophyll fluorescence (Fv’/Fm’) of W. Murcott mandarin grafted onto Carrizo, sour orange, and Volkameriana rootstocks under drought stress. Mean values in the same column with different letters are significantly different according to Tukey’s test (p = 0.05). ns: not significant.
Table 3. Rootstock diameter (mm), scion diameter (mm), leaf Chl concentration (SPAD readings), and chlorophyll fluorescence (Fv’/Fm’) of W. Murcott mandarin grafted onto Carrizo, sour orange, and Volkameriana rootstocks under drought stress. Mean values in the same column with different letters are significantly different according to Tukey’s test (p = 0.05). ns: not significant.
RootstockDIRootstock Diameter (mm)Scion Diameter (mm)SPADFv’/Fm’
Carrizo 0.48 b0.26 b45.93 b0.52
Sour orange 0.79 a0.32 b54.18 a0.53
Volkameriana 0.81 a0.50 a48.62 b0.51
40%0.47 b0.2944.63 b0.40 c
50%0.64 b0.3548.02 b0.55 b
Control0.98 a0.4456.07 a0.62 a
Carrizo40%0.29 d0.2842.260.38
50%0.55 bcd0.1744.540.55
Control0.61 bcd0.3250.980.65
Sour orange40%0.66 bcd0.2646.880.39
50%0.82 bc0.3250.080.56
Control0.90 b0.3865.580.64
Volkameriana40%0.45 cd0.3344.740.43
50%0.55 bcd0.5649.450.54
Control1.43 a0.6251.660.56
LSD0.05Rootstock0.2390.1294.121ns
Treatment0.239ns4.1210.057
Interaction0.414nsnsns
Table 4. Transpiration rate = E (mmol m−2s−1), photosynthetic rate = PN [µmol(CO2) m−2s−1], stomatal conductance = gSw (mmol m−2s−1), and photosynthetic leaf water-use efficiency (WUE = PN/E) of W. Murcott mandarin grafted onto Carrizo, sour orange, and Volkameriana rootstocks under drought stress. Mean values in the same column with different letters are significantly different according to Tukey’s test (p = 0.05). ns: not significant.
Table 4. Transpiration rate = E (mmol m−2s−1), photosynthetic rate = PN [µmol(CO2) m−2s−1], stomatal conductance = gSw (mmol m−2s−1), and photosynthetic leaf water-use efficiency (WUE = PN/E) of W. Murcott mandarin grafted onto Carrizo, sour orange, and Volkameriana rootstocks under drought stress. Mean values in the same column with different letters are significantly different according to Tukey’s test (p = 0.05). ns: not significant.
RootstockDIPNEgSwWUE
Carrizo 5.25 c1.6134.003.36
Sour orange 6.57 a2.0641.783.33
Volkameriana 5.91 b1.9139.673.23
40%5.35 b1.68 b38.003.19
50%5.67 b1.71 b35.673.42
Control6.70 a2.16 a41.783.22
Carrizo40%4.861.5035.003.47
50%4.981.6330.003.10
Control5.901.6937.003.50
Sour orange40%6.021.8741.673.44
50%6.001.6235.333.71
Control7.682.7048.332.85
Volkameriana40%5.181.7737.332.94
50%6.021.8741.673.44
Control6.522.1040.003.31
LSD0.05Rootstock0.592nsnsns
Treatment0.4930.411nsns
Interactionnsnsnsns
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Incesu, M.; Cimen, B.; Yilmaz, B.; Yesiloglu, T.; Ilhan, M. Physiological Investigation of Drought Stress Tolerance of ‘W. Murcott’ Mandarin Grafted onto ‘Carrizo’, ‘Sour Orange’, and ‘Volkameriana’ Rootstocks. Horticulturae 2025, 11, 365. https://doi.org/10.3390/horticulturae11040365

AMA Style

Incesu M, Cimen B, Yilmaz B, Yesiloglu T, Ilhan M. Physiological Investigation of Drought Stress Tolerance of ‘W. Murcott’ Mandarin Grafted onto ‘Carrizo’, ‘Sour Orange’, and ‘Volkameriana’ Rootstocks. Horticulturae. 2025; 11(4):365. https://doi.org/10.3390/horticulturae11040365

Chicago/Turabian Style

Incesu, Meral, Berken Cimen, Bilge Yilmaz, Turgut Yesiloglu, and Merve Ilhan. 2025. "Physiological Investigation of Drought Stress Tolerance of ‘W. Murcott’ Mandarin Grafted onto ‘Carrizo’, ‘Sour Orange’, and ‘Volkameriana’ Rootstocks" Horticulturae 11, no. 4: 365. https://doi.org/10.3390/horticulturae11040365

APA Style

Incesu, M., Cimen, B., Yilmaz, B., Yesiloglu, T., & Ilhan, M. (2025). Physiological Investigation of Drought Stress Tolerance of ‘W. Murcott’ Mandarin Grafted onto ‘Carrizo’, ‘Sour Orange’, and ‘Volkameriana’ Rootstocks. Horticulturae, 11(4), 365. https://doi.org/10.3390/horticulturae11040365

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