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Review

Research Progress on the Effect of Grafting Technology on Disease Resistance and Stress Resistance of Watermelon

by
Xuena Liu
1,2,†,
Shikai La
1,2,†,
Chang Chen
3,
Ainong Shi
4,
Mingjiao Wang
1,2,
Yingying Zhang
1,2,
Jinghua Guo
1,2,* and
Lingdi Dong
1,2,*
1
Institute of Cash Crops, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China
2
Hebei Vegetable Engineering Technology Centre, Institute of Cash Crops, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang 050051, China
3
Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China
4
Department of Horticulture, University of Arkansas, Fayetteville, AR 72701, USA
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Horticulturae 2025, 11(10), 1271; https://doi.org/10.3390/horticulturae11101271
Submission received: 19 September 2025 / Revised: 17 October 2025 / Accepted: 20 October 2025 / Published: 21 October 2025
(This article belongs to the Special Issue The Role of Rootstock in Horticultural Crops and Its Influence on Growth and Development)
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Abstract

Grafting is an effective horticultural technique that significantly enhances disease resistance and stress tolerance in watermelon. This review systematically summarizes the types of rootstocks used in watermelon grafting and analyzes the effects of grafting on plant responses to biotic stresses, such as viral and fungal pathogens, root-knot nematodes infections, and abiotic stresses, including drought, temperature extremes, and salinity. Furthermore, it discusses the changes in fruit quality and explores the underlying mechanisms associated with graft-induced resistance. By synthesizing recent research advances, this review aims to offer valuable insights and practical references for improving resistance and promoting sustainable production in cucurbit and other vegetable crops through grafting. As a sustainable cultivation strategy, grafting demonstrates considerable potential for enhancing watermelon resilience and yield; however, optimizing fruit quality remains a critical focus for future research.

1. Introduction

Grafting, a horticultural technique that enhances crop resistance and yield by integrating selected rootstocks and scions, is extensively utilized in agricultural production [1,2,3]. It has proven particularly effective in enhancing the productivity and quality of cucurbit vegetables, such as watermelon, in many countries [4].
During long-term domestication and selective breeding focused on fruit appearance and yield, watermelons have experienced a significant decline in innate stress tolerance. Biotic stresses, such as Fusarium wilt, pose a serious threat to production. Similarly, abiotic challenges, including drought, salinity, and temperature extremes, substantially constrain watermelon growth and quality [5,6,7,8,9]. Grafting technology offers a viable solution to enhance watermelon resistance to both biotic and abiotic stresses [10] (Figure 1).
This paper systematically reviews the effects of grafting technology on disease resistance (including viruses, fungal, and root-knot nematodes), stress resistance (such as drought, temperature, and salt stress), and fruit quality of watermelon. Furthermore, it summarizes the underlying mechanisms through which grafting confers enhanced disease and stress resistance. The aim is to provide a reference for both theoretical research and practical applications aimed at improving resistance in watermelon and other cucurbit vegetables by grafting technology.

2. Grafting Affects the Tolerance of Watermelon to Biotic Stress

2.1. Virus Disease

There are several virus diseases for watermelon such as watermelon mosaic virus (WMV), watermelon curly mottle virus (WCMV), melon yellow spot virus (MYSV), melon necrotic spot virus (MNSV), papaya leaf distortion mosaic virus (PLDMV), papaya ringspot virus watermelon strain (PRSV-W), cucumber green mottle mosaic virus (CGMMV), melon aphid-borne yellows virus (MABYV), and Citrullus lanatus cryptic virus (CiLCV) [9,11,12].
Although reports on the use of grafting to mitigate viral diseases in watermelon remain limited, some studies indicate that grafting can enhance plant resistance to certain viruses (Table 1). This protective effect depends on the choice of rootstock with antiviral properties. Selecting appropriate rootstocks can significantly restrict viral spread and replication within plants. For example, grafting increased watermelon production by 115% in fields infected with MNSV [13]. In another study, [14] reported that grafting watermelon onto a hybrid squash rootstock (RS-841) significantly improved scion resistance to MNSV.
Previous research has shown that grafting can generally enhance the overall virus tolerance of seedless watermelons [23]. However, their efficacy entirely depends on the rootstock selected. It is also important to note that grafting cannot cure existing viral infections. For certain viruses, such as CGMMV, infection present in the scion before grafting will persist post-grafting [23]. Therefore, the selection and use of highly resistant rootstocks are essential for effective viral disease management.
Furthermore, the development of antiviral rootstocks through genetic engineering represents a promising research direction [24]. Transgenic rootstocks resistant to CGMMV have been successfully developed by introducing cDNA encoding the viral coat protein gene [25]. Notably, antiviral transgenic rootstocks engineered via RNA silencing technology can confer systemic resistance to susceptible scions grafted onto them [26]. This advancement presents new opportunities for integrated management of watermelon viral diseases through grafting in future agricultural practices.

2.2. Fungal Diseases

Fusarium wilt, gummy stem blight, colletotrichum orbiculare, and powdery mildew are the principal fungal diseases that pose serious threats to watermelon production [8,27]. Grafting is recognized as an effective management strategy for these diseases, particularly those caused by soil-borne pathogens [3] (Table 1).
The selection of resistant rootstocks, such as bottle gourds, pumpkins, and wild watermelons relatives, can significantly improve scion resistance to Fusarium wilt. Grafting onto these rootstocks has been shown to substantially reduce disease indices and incidence rates. In some cases, grafting can eliminate the disease entirely; one study reported 100% and 88% reductions in Fusarium wilt occurrence in grafted plants compared to non-grafted seedlings [16]. Furthermore, [28] indicated that grafting can modulate the rhizosphere bacterial community. By utilizing core bacterial strains isolated from the roots of grafted plants, they successfully constructed a synthetic beneficial microbial that enhanced both growth and disease resistance in non-grafted watermelons cultivated in non-sterilized soil.
Therefore, selecting rootstocks with inherent resistance is a critical component for improving fungal disease management in grafted watermelons. [7] grafted the scion cultivar ‘Mickey Lee’, which is susceptible to powdery mildew, onto 25 watermelon cultivars and four gourd rootstocks. The results demonstrated that specific gourd rootstocks (USVL482-PMR and USVL351-PMR) conferred a significantly higher level of powdery mildew resistance to the scion than watermelon rootstocks.

2.3. Root-Knot Nematode

Watermelon root-knot nematode disease, primarily caused by Meloidogyne spp. (especially Meloidogyne incognita), poses a significant challenge to watermelon production worldwide [29]. This pathogen damages the root system by forming galls or root nodules. These structures result in shortened roots, impaired root development, and reduced root activity [30,31]. The corresponding above-ground symptoms include plant stunting, leaf curling, yellowing, and wilting [32,33], which can lead to plant death in severe cases. Consequently, plant growth and vigor are compromised, leading to reduced fruit set, lower yields, and inferior fruit quality (Table 1).
Chemical control of root-knot nematodes often shows limited efficacy due to their adaptability, while also posing environmental risks and potential for resistance development [34]. Consequently, grafting has been developed as a viable management strategy for this disease [3,35]. This technique involves grafting susceptible watermelon scions onto rootstock cultivars that are resistant to root-knot nematodes, thereby controlling infection [21].
Certain varieties of bottle gourd (Lagenaria siceraria) and interspecific hybrid pumpkin (Cucurbita moschata × C. maxima) have been identified as effective resistant rootstocks for this disease. Their use significantly reduces nematode infection levels and root gall formation while improving watermelon yield [21]. Field trials have demonstrated high resistance in rootstock cultivars such as ‘Emphasis’, ‘Carnivor’ and ‘Strongto’. Resistance has also been reported in wild watermelon (Citrullus amarus) and some wild cucumber resources (e.g., Cucumis myriocarpus), suggesting their potential as rootstocks [22]. Germplasm resources of Citrullus lanatus var. citroides represents another source of potential rootstock material with resistance to root-knot nematodes [36]. The RKVL rootstocks series, developed by the United States Department of Agriculture from wild watermelons, has shown superior performance against nematodes compared to commercial rootstocks and non-grafted plants. Under field conditions with high nematode pressure, the root-knot rates for RKVL rootstocks were 9–16%, which was significantly lower than the 41% rate observed in non-grafted cultivars [37].

3. Grafting Affected the Tolerance of Watermelon to Abiotic Stress

3.1. Drought Stress

Drought stress presents a significant challenge to plant cultivation, particularly for high-water-demand crops, like watermelon, in arid and semi-arid regions. Grafting commercial varieties onto drought-tolerant rootstocks offers a potential strategy for mitigating these challenges. Tolerant rootstocks typically develop more extensive root systems, facilitating more efficient absorption of soil water and nutrients, thereby providing a stronger foundation for the scion under water-deficit conditions [38] (Table 2). Under continuous severe water stress, non-grafted watermelon plants can suffer yield losses of up to 40%, a consequence of reduced single-fruit weight and a lower fruit set [39,40].
The use of drought-resistant rootstocks enhances the ability of grafted watermelon plants to both avoid and tolerate drought stress. Physiological improvements include the maintenance of a high leaf relative water content and improved water-use efficiency (WUE) [44]. This is partly achieved through the rapid adjustment of the stomatal aperture to control transpiration [41,45]. Furthermore, grafting induces beneficial molecular and biochemical changes in the host. For example, grafting onto the pumpkin rootstock ‘Naihan 1’ upregulates ClTCP4 gene expression in the watermelon scion. This genetic change is associated with a 38% increase in the net CO2 assimilation rate and a 45% reduction in malondialdehyde (MDA) levels, indicating enhanced photosynthetic capacity and greater cell membrane stability [42], respectively.
Ref. [61] provided key multi-omics data on the variation in genes and metabolites under drought stress, which is important for understanding the mechanisms underlying graft-induced drought resistance. Additionally, grafted plants exhibit significantly higher antioxidant enzyme activity during drought stress. Concurrently, indices of oxidative damage were markedly lower in these plants than in self-rooted watermelon [41].
Field trials have confirmed the influence of rootstock type on the extent of increased drought resistance. Commercial pumpkin hybrid rootstocks (Cucurbita maxima Duch. × Cucurbita moschata Duch. rootstock ‘Shintoza’) [41,43] and other types of bottle gourd rootstocks, such as ‘Illapel’ and ‘Osorno’ [10], can effectively increase the yield of grafted watermelon under drought or less water conditions.

3.2. Temperature Stress

Watermelon is a thermophilic crop, and it is highly sensitive to low temperatures stress (Table 2). Low-temperature stress can seriously affect plant growth and development, interfere with plant physiological functions, and even result in plant death [47,48]. For instance, when post-planting temperatures remain around 2 °C for 14–15 h, watermelon yields can decrease by more than 10% [62]. The grafting technique is widely used to improve the low-temperature resistance of watermelon.
Grafting watermelon onto pumpkin rootstocks improves chilling resistance by maintaining higher chlorophyll content and photosynthetic rates under cold stress. Additionally, they exhibit a significant reduction in MDA content, indicating diminished cell membrane damage due to cold stress [47,49]. Typically, low temperatures suppress the activity of antioxidant enzymes in watermelon, adversely affecting photosynthesis and root development [47,63]. However, grafting significantly enhances the capacity of plants to eliminate reactive oxygen species (ROS), thereby mitigating oxidative damage. This enhancement is closely associated with the dynamic interactions between ROS and salicylic acid (SA), which may be a key mechanism underlying grafting-induced cold tolerance [49]. Further studies have indicated that pumpkin rootstocks improves cold resistance in watermelon seedlings by promoting the accumulation of melatonin and methyl jasmonate (MeJA) and increasing the levels of hydrogen peroxide (H2O2) [50].
Transcriptome analyses revealed that grafting altered the expression of many low-temperature-related genes in watermelon seedlings. This provides a molecular basis for better survival and growth under low temperatures [64]. For example, pumpkin rootstocks upregulate the arginine decarboxylase (ADC) gene, leading to the production of more putrescine, which helps mitigate the harmful effects of low temperatures [65]. Grafting can also alter the expression of genes related to the Calvin cycle, further enhancing cold adaption [47]. Insights from muskmelon studies suggest that miRNA-mediated gene regulation may also contribute to enhanced cold tolerance [66].
However, it is also necessary to mention that there are many differences in cold tolerance among various rootstocks. Rootstocks with good cold tolerance, such as the bottle gourd varieties ‘2505’ and ‘0526’, help improve the cold tolerance of grafted watermelons [47]. Grafting onto bottle gourd rootstocks can enhance cold tolerance, particularly during early growth stages, without compromising fruit commercial quality [20].
Elevated temperatures resulting from global warming have emerged as a significant threat to the yield and quality of watermelon [67]. Although systematic studies on heat tolerance in grafted watermelon remain limited, existing evidence have indicated their potential advantages. Grafting has been shown to have a beneficial effect on cucumber yield under combined stress conditions (heat and salt) [68]. Rootstocks, mostly pumpkin or bottle gourds, generally feature more extensive root systems with superior water and nutrient uptake capacity, which helps maintain plant water status under high-temperature conditions and indirectly enhances heat [69].

3.3. Salt Stress

Soil salinization is a major abiotic factor that affects the yield of crops worldwide (Table 2). In watermelon, salt stress leads to growth inhibition, osmotic stress, ion toxicity, and secondary oxidative stress, collectively limiting plant development and productivity [51,70,71,72,73,74]. Research indicates that grafting salt-tolerant rootstocks is an effective strategy for enhancing salt stress tolerance [51].
Variations in salt tolerance mechanisms are observed among different rootstocks, such as the Na translocation strategy [55,56,75,76]. Pumpkin rootstocks, such as ‘Kaijia No. 1’, showed much better salt tolerance [56]. Interestingly, autotetraploid watermelon rootstocks showed more salt-stress tolerance than diploid watermelon rootstocks, suggesting that autotetraploid watermelon may have a larger ion transportation capability of K+ and Na+ accumulation for its replication genome to enhance these functions, including ion absorption/transportation adjustment ability and antioxidant capability [57].
Grafting with salt-resistant rootstocks enhances plant salt resistance through ‘ion exclusion’ mechanisms, whereby Na+ transport from roots to shoots is restricted. This significantly reduces Na+ accumulation in leaves and helps maintain a balanced K+/Na+ ratio in scion tissue [75]. For example, watermelons grafted onto bott gourd rootstock showed much less accumulation of Na+ and significantly maintained leaf ion levels (the K+/Na+ ratio) in a balanced range, and also preserved stable cell osmotic pressure [56,58], with an accumulation of osmotic adjustment substances, such as soluble sugars [55].
In addition, under salt stress, grafted plants maintain or enhance the activity of antioxidant enzymes in leaves [51,52,53]. This increased enzymatic activity mitigates reactive oxygen species (ROS) overproduction and reduces oxidative damage, including membrane lipid peroxidation, thereby protecting cellular membrane integrity and function [51,77].
Transcriptomic and proteomic analyses have revealed a comprehensive molecular network activated by grafting, which may represent an adaptive response initiated by alterations in the local hormonal balance. Ref. [51] studied that 8462 differentially expressed genes were identified in grafted watermelon seedlings under salt stress, demonstrating that grafting onto gourd rootstock significantly alleviated salt-induced growth inhibition and photosynthetic decline. This widespread transcriptomic reprogramming likely reflects the systemic adjustments triggered by rootstock-induced hormonal signals. Similarly, proteomic analyses have indicated that grafting and/or salt stress alters the expression of 40 proteins involved in key processes, such as the Calvin cycle, amino acid biosynthesis, sugar and energy metabolism, ROS defense system, and hormone signaling pathways [54]. Ref. [59] further reported that grafting onto gourd rootstock led to dynamic changes in at least 12 proteins under prolonged 50 mmol/L NaCl stress. Additional studies have highlighted grafting-induced modulation of salt-responsive genes, including ion transporters (e.g., SOS, HKT1, NHX1, and PMA) and transcription factors, such as NAC and WRKY [51,60]. Moreover, ref. [77] demonstrated that the transcription factor ClaDREB14 positively regulates the peroxidase gene ClaPOD6, enhancing peroxidase activity and contributing to improved salt tolerance in grafted watermelons. These multilevel molecular changes collectively underscore grafting-induced adaptive mechanisms, potentially orchestrated by hormonal rebalancing, which enhances stress resilience.

4. Effects of Grafting on Fruit Quality of Watermelon

Watermelon fruit quality is a multifaceted concept that encompasses several key attributes that influence consumer perception and acceptance. These attributes primarily include appearance characteristics (size, shape, and color), internal quality characteristics (flesh color and texture), nutrients (lycopene and vitamin C), and flavor characteristics (soluble solids, soluble sugars, and organic acids) [78]. Sugar and soluble solid contents (SSC) both affect the sweetness of fruits, and consumer taste is directly influenced. Among them, SSC is an important index for evaluating watermelon sweetness [79,80,81]. Lycopene is one of the essential pigments that can give red coloration to watermelon but it also works as the antioxidant functions, plays an important role in measuring the nutritional value of watermelons [79,82] (Table 3).

4.1. Soluble Solids Content

Grafting has been observed to potentially reduce SSC and total sugar content. Ref. [95] indicated that the SSC of watermelon fruits grafted onto rootstocks from Citrullus lanatus var. citroides decrease. Ref. [83] found that fruit quality, including sugar content, of seedless watermelons grafted onto pumpkin rootstocks might be adversely affected. Conversely, some studies have indicated that grafting could enhance the SSC in watermelon, especially on gourd rootstocks, where the SSC increased by 12 to 15% [84,85,98]. Ref. [81] found that grafting pumpkin rootstocks altered the sugar composition and increased the weight of watermelon fruits through the action of invertase and sugar transporters. Transcriptome analyses have shown that pumpkin rootstocks upregulated the expression of genes involved in fructose/mannose metabolism in the flesh, increase the activity of sucrose synthase, and enhance the transfer of carbohydrates into fruits. Furthermore, grafting onto pumpkin rootstocks leads to an optimization of sugar distribution efficiency in sink tissues by regulating key factors such as the sugar transporter SWEET10 [84,85]. The mRNAs exchanged between the rootstock and scion have been implicated in improving watermelon fruit quality, potentially involving the regulation of sugar metabolism pathways [99].

4.2. Organic Acid

Grafting influences organic acid metabolism in watermelon fruits, thereby affecting their quality and flavor. Some studies have indicated that grafting can increase the total organic acids and titratable acidity of watermelon during fruit ripening [82,100]. Different rootstock combinations in grafting experiments showed significant differences in fruit organic acids [80,101]. Regarding specific organic acid types, grafting exerts a regulatory effect on the content of key organic acids such as citric acid and malic acid. In a metabolomic study of pumpkin rootstock-grafted watermelon, 56 primary metabolites were identified, with notable differences in organic acid profiles between grafted and self-rooted plants. Specifically, citric acid content increased while malic acid decreased, leading to an altered sugar-acid balance in the fruit [86].
The regulation of organic acid accumulation is primarily regulated by key metabolic enzymes. Grafting has the potential to influence the metabolic pathways of organic acids by altering the enzyme activity. For instance, in the ‘Zaojia’ watermelon grafting experiment, variations in the activities of acid invertase (AI), neutral invertase (NI), sucrose synthase (SS), and sucrose phosphate synthase (SPS) were documented. These enzymes play a role in sugar metabolism, and changes in their activity are indirectly associated with the accumulation of organic acids [80].
A comprehensive analysis of transcriptome and metabolome revealed that pumpkin rootstocks modify gene activity in plant biochemical processes. Over 216 chemical compounds differed between non-grafted and grafted watermelon, mainly in flavonoid biosynthesis affecting fruit flavor [85]. Gene networks linked to sugar and organic acid accumulation were identified through transcriptome analysis [102,103]. The translocation of signals between plant parts, including 834 mobile RNAs identified in pumpkin-grafted watermelon, may enhance grafted fruit quality [99].

4.3. Lycopene

Lycopene is a powerful antioxidant, and its increased consumption positively influences human health [104]. Studies have found that lycopene bioavailability in watermelons is higher than that in tomatoes, with an efficiency of more than 60% [105,106]. Many studies on lycopene and its biological activities have verified that lycopene possesses bioactivities, including anti-cancer, antioxidant, anti-aging, and prevention or cure of cardiovascular diseases [107,108,109].
Specific graft combinations have been shown to increase the lycopene content in watermelon fruits. For instance, grafting watermelon onto interspecific hybrid pumpkin rootstocks increased lycopene levels [87,110]. Similarly, watermelons grafted onto bottle gourd and pumpkin hybrid rootstocks exhibited higher lycopene content than non-grafted controls [88,110]. This enhancement may result from rootstock-mediated transcriptional regulation of lycopene metabolism genes [88]. Comparative analyses further corroborated that grafting combinations can augment lycopene content [111].
Regarding the impact of rootstocks on lycopene content in watermelon, current research findings remain inconclusive. Some studies suggest that different rootstocks can have varying effects on lycopene content due to factors such as the combination of scion and rootstock, planting environment, and fruit maturity. This influence may also differ depending on fruit set conditions and cultivation practices [19,112,113,114]. However, other studies have indicated that there is no significant difference in lycopene content between grafted and non-grafted watermelon fruits [115].
Grafting also influences the temporal pattern of lycopene accumulation. Research indicates that grafting can delay lycopene accumulation during fruit development, resulting in postponed color peaks in mature fruits [82,89]. This delay may be attributed to the fact that grafting significantly reduced the concentration of abscisic acid (ABA) in the fruit, which is essential for promoting fruit ripening. Reduction in ABA concentration may indirectly affect both the rate of accumulation and final lycopene content [90].

4.4. Physical and Sensory Quality

Grafting, particularly with Cucurbita rootstocks, is widely considered as a method for improving watermelon flesh firmness [82,91,92]. For instance, compared with the non-grafting control, the flesh firmness of watermelon grafted with pumpkin rootstocks was significantly higher [93]. This increase may be attributed to alterations in the cell wall structure or increased cell density of the fruit flesh [92]. However, not all studies support this finding. Some studies have indicated that grafting does not influence firmness [94,113], and may result in a reduction in firmness under specific rootstock/scion combinations [83,95]. For instance, watermelon is grafted onto zucchini rootstocks [95]. This change often correlates with rootstock genotypes, scion varietal species, and cultivation environments [114].
Beyond flesh firmness, grafting may also affect other fruit quality traits. Several studies have indicated that grafting can increase peel thickness [91], which may extend the shelf life of fruits and enhance their resistance to damage during transportation. Furthermore, grafting onto certain rootstocks may reduce the sensitivity of watermelons to fruit cracking, a condition associated with increased fruit toughness [92]. Regarding fruit morphology, grafting has been found to affect fruit weight and size [96] and increasing the weight of individual fruits [81].

5. Mechanism of Grafting Affecting Disease and Stress Resistance of Plants

5.1. Biotic Stress Resistance

The core of grafting technology in enhancing plant resistance to biotic stress is the synergistic interaction between the rootstock and scion. The selection of appropriate rootstocks is crucial, particularly for conferring resistance against soil-borne pathogens [116,117]. Grafting primarily augments plant disease resistance by facilitating efficient material exchange and long-distance signal transduction between rootstocks and scions [118,119]. This physical connection facilitates the transport of nutrients and hormone signals, and defense-related molecules [120,121,122,123]. For instance, jasmonic acid (JA) and its derivatives participate in systemic defense responses. Grafting experiments have demonstrated their involvement in long-distance signal transduction by activating defense mechanisms against herbivores [124]. Similarly, SA acts as a key signaling molecule in systemic acquired resistance (SAR), where its accumulation promotes NPR1 protein activation and confers broad-spectrum disease resistance [125,126,127].
Grafting can influence activation and regulation of the plant innate immune system. Plants respond to pathogens via pattern-triggered immunity (PTI), mediated by pattern recognition receptors (PRRs), and effector-triggered immunity (ETI), mediated by effector recognition receptors (NLRs) [128]. Rootstocks can transfer signal molecules to scions, thereby enhancing their PTI or ETI response. Moreover, beneficial rhizosphere microorganisms, including bacteria and fungi, can induce systemic resistance (ISR), which may be enhanced or transmitted through grafting to improve plant resistance to pathogens and pests [127,129,130,131]. ISR largely depends on the modulation of hormone signaling pathways involving JA, ethylene (ET), SA, along with associated gene expression changes [129].
Beyond signal transduction, grafting may induce epigenetic modifications that regulate gene expression without altering the DNA sequence [120,132,133]. For instance, the DNA demethylation observed during eggplant grafting is correlated with increased grafting activity [133]. These epigenetic changes may underlie the long-term enhancement of resistance in grafted plants as they can influence the plant’s memory effect regarding stress and its future response capabilities.
Furthermore, grafting can stimulate the production of antioxidant enzymes such as superoxide dismutase, catalase, and peroxidase, which help scavenge reactive oxygen species and alleviate oxidative stress [134,135]. Grafting may influence the accumulation of secondary metabolites that are vital for the defense against pathogens and pests [122,123]. Certain rootstocks enhance the accumulation of secondary metabolites with defensive properties in scions, thereby improving disease resistance [123].

5.2. Abiotic Stress Resistance

The mechanism by which grafting influences plant tolerance to abiotic stress is multifaceted, involving morphological, physiological, biochemical, and molecular adaptations [122,136]. Selecting suitable rootstocks is essential for optimizing morphological and physiological adjustments. Robust rootstock roots can absorb more water and nutrients, thereby effectively improves the stress resistance of the entire plant [117,137,138]. Grafting has been shown to increases the photosynthetic efficiency and water-use efficiency of crops [139]. Under drought stress, grafted cucumber plants exhibit significantly less damage in scions, indicating that rootstocks can effectively mitigate the adverse effects of water deficit [140]. Similarly, grafted grapes exhibit improved physiological and biochemical responses under drought stress, including enhanced osmotic adjustment and antioxidant enzyme activity [141]. Furthermore, salt-tolerant rootstocks can limit the translocation of harmful ions (such as Na+) to aerial parts, thereby improving the tolerance of plants to saline-alkali stress [138,142].
Long-distance signal and communication between rootstocks and scions constitute a fundamental mechanism underlying grafting enhanced stress resistance [118,120,136]. The formation of local hormone gradients is pivotal for orchestrating this process [143,144]. For instance, rootstocks improve scion cold tolerance by facilitating scion signals of melatonin, MeJA, and H2O2 accumulation in grafted watermelon plants [50]. Various hormones, including ABA, ET, JA, CKs, and SA, are involved in regulation of signal pathways in grafted plants [143,144]. In addition, rootstocks can transmit mobile mRNAs to scions, contributing significantly to enhanced stress tolerance [145]. Although the specific molecular transport mechanism is still under investigation, molecular communication between rootstock and scion is clearly a key factor in the adaptation of grafted crops to adverse environments [120].
The molecular basis of grafting-induced abiotic stress tolerance involves gene regulatory networks [146,147]. Abiotic stress typically trigger the expression of a series of stress-related genes in plants [148], while grafting can enhance plant tolerance by modulating the expression of such stress-related genes. Transcriptome studies have revealed the altered expression of heat tolerance-related genes changed in grafting roses under high-temperature stress [149], and differential gene expression patterns in grafted grapevines under drought conditions [141]. Epigenetic regulation plays a crucial role in this process and in the formation of plant stress memory [120,144,147,150]. For example, self-grafted tomato plants can induce changes in histone modifications and DNA methylation, which are closely associated with the enhanced tolerance of plants to drought [151]. As an key mechanism for plants to adapt to extreme environments, DNA methylation can lead to fluctuations in the expression levels of stress-related genes, thereby enhancing resilience [150]. Plant-microorganism interactions represent another important dimension. Plant biostimulants and rhizosphere-beneficial microorganisms (such as extracellular polysaccharide EPS produced by rhizosphere bacteria) can enhance plant tolerance to drought, salinity, and heavy metals [152,153]. However, grafting can promote this beneficial interaction, thereby enhancing plant adaptability to environmental stresses [154].

6. Conclusions and Prospects

Grafting is an effective technique for enhancing the disease and stress resistance of watermelon. It confers resistance to biotic stresses using rootstocks to prevent virus, fungi, and nematode proliferation and transfers systemic resistance signals to scions. In response to abiotic stress, drought-, salt-, and cold-tolerant rootstocks improve scion performance through enhanced root architecture, increased photosynthetic efficiency, and activated antioxidant systems. Hormones, proteins, and mobile RNAs mediate the relationships between rootstocks and scions to regulate transcriptomes and metabolomes for stress response. While grafting can increase fruit size, lycopene concentration, and shelf life, its effects on other quality traits vary with rootstock–scion combinations. Therefore, selecting rootstocks with strong stress resistance and high graft compatibility is essential to maintain fruit quality and achieve high yields.
Future research should focus on two key directions: first, the strategic integration of breeding with grafting to develop advanced rootstocks that provide perennial multi-stress resistance and ensure fruit quality, potentially enabling pre-emptive control against complex diseases. Second, a comprehensive investigation into the long-term effects on soil ecosystems is essential, particularly concerning the impact of grafting on microbial communities and biochemical processes in deeper soil layers and how these effects can be optimized together with soil amendments to amendments soil health and sustainability.
For widespread adoption, economic and agronomic feasibility must be considered. While grafting is highly profitable in commercial systems where yield gains offset costs, its economic viability remains challenging for small-scale farmers [19]. Bridging this gap requires the development more accessible and affordable grafting solutions. Finally, future studies should extend beyond greenhouse conditions to systematically evaluate grafted plant performance, stress stability, and rootstock–scion compatibility under diverse open-field conditions.

Author Contributions

Conceptualization, X.L., L.D. and J.G.; methodology, X.L. and C.C.; software, X.L. and S.L.; validation, X.L. and A.S.; formal analysis, X.L. and S.L.; investigation, X.L., M.W. and Y.Z.; resources, S.L. and C.C.; data curation, X.L., M.W. and Y.Z.; writing—original draft preparation, X.L., S.L. and C.C.; writing—review and editing, X.L. and A.S.; supervision, L.D. and J.G.; project administration, L.D. and J.G.; funding acquisition, L.D. and J.G. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the International Science and Technology Cooperation Project of the Hebei Academy of Agriculture and Forestry Sciences (2023KJCXZX-JZS-GH02); Hebei Academy of Agriculture and Forestry Sciences Modern Agricultural Science and Technology Innovation Project (2022KJCXZX-JZS-7); Technical system of vegetable industry in Hebei province, Southern Hebei high quality vegetable technology promotion post (HBCT2023100205).

Data Availability Statement

Data are contained within the article.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Bahadur, A.; Singh, P.M.; Rai, N.; Singh, A.K.; Singh, A.K.; Karkute, S.G.; Behera, T.K. Grafting in Vegetables to Improve Abiotic Stress Tolerance, Yield and Quality. J. Hortic. Sci. Biotechnol. 2024, 99, 385–403. [Google Scholar] [CrossRef]
  2. Augstein, F.; Melnyk, C.W. Modern and Historical Uses of Plant Grafting to Engineer Development, Stress Tolerance, Chimeras, and Hybrids. Plant J. 2025, 121, e70057. [Google Scholar] [CrossRef] [PubMed]
  3. Singathiya, P.; Mahala, P.; Yadav, L.P.; Varotariya, K.; Brahmani, G.; Sohi, A.; Choudhary, R.; Jangu, R.; Uikey, P.; Kumar, S. Advanced Grafting Techniques for Mitigating Biotic and Abiotic Stresses in Vegetable Crops: Breeding and Biotechnological Approaches. Biotechnol. Environ. 2025, 2, 9. [Google Scholar] [CrossRef]
  4. Liu, C.; Lin, W.; Feng, C.; Wu, X.; Fu, X.; Xiong, M.; Bie, Z.; Huang, Y. A New Grafting Method for Watermelon to Inhibit Rootstock Regrowth and Enhance Scion Growth. Agriculture 2021, 11, 812. [Google Scholar] [CrossRef]
  5. Kantor, M.; Levi, A. Utilizing Genetic Resources and Precision Agriculture to Enhance Resistance to Biotic and Abiotic Stress in Watermelon. Not. Sci. Biol. 2018, 10, 1–7. [Google Scholar] [CrossRef]
  6. Zhang, M.; Xu, J.; Ren, R.; Liu, G.; Yao, X.; Lou, L.; Xu, J.; Yang, X. Proteomic Analysis of Fusarium oxysporum-Induced Mechanism in Grafted Watermelon Seedlings. Front. Plant Sci. 2021, 12, 632758. [Google Scholar] [CrossRef]
  7. Kousik, C.S.; Mandal, M.; Hassell, R. Powdery Mildew Resistant Rootstocks that Impart Tolerance to Grafted Susceptible Watermelon Scion Seedlings. Plant Dis. 2018, 102, 1290–1298. [Google Scholar] [CrossRef] [PubMed]
  8. Tong, Y.; Du, H.; Xiao, J.; Zhou, B.; Zheng, X.; Deng, Y.; Zheng, X.; Chen, M. Watermelon Wilt Disease: Causes, Harms, and Control Measures. Front. Microbiol. 2025, 16, 1601130. [Google Scholar] [CrossRef]
  9. Byun, H.-S.; Choi, H.-S.; Kim, H.R.; Kwak, H.-R.; Kil, E.-J.; Kim, M. First Report of Melon Aphid-Borne Yellows Virus Infecting Watermelon in Korea. Plant Dis. 2022, 106, 1766. [Google Scholar] [CrossRef]
  10. Morales, C.; Riveros-Burgos, C.; Espinoza Seguel, F.; Maldonado, C.; Mashilo, J.; Pinto, C.; Contreras-Soto, R.I. Rootstocks Comparison in Grafted Watermelon under Water Deficit: Effects on the Fruit Quality and Yield. Plants 2023, 12, 509. [Google Scholar] [CrossRef]
  11. Ma, G.; Kang, H. The Research Advance of Virus Diseases in the Cucurbitaceae. Heilongjiang Agric. Sci. 2001, 1, 44–47. [Google Scholar]
  12. Zhao, L.; Qiu, Y.; Zhang, X.; Liu, H.; Yang, J.; Zhang, J.; Zhang, H.; Xu, X.; Wen, C. The Detection of Citrullus lanatus Cryptic Virus Using TaqMan-qPCR Method. Sci. Agric. Sin. 2021, 54, 4337–4347. [Google Scholar]
  13. Huitrón-Ramírez, M.V.; Ricárdez-Salinas, M.; Camacho-Ferre, F. Influence of Grafted Watermelon Plant Density on Yield and Quality in Soil Infested with Melon Necrotic Spot Virus. HortScience 2009, 44, 1838–1841. [Google Scholar] [CrossRef]
  14. Felipe, A.; García López, F.; González-Eguiarte, D.; Macías, R.; Zarazúa, P.; María, V.; Huitrón, R. Watermelon Production with Rootstocks in Soils Infested with the Melon Necrotic Spot Virus. Rev. Mex. Cienc. Agríc. 2018, 9, 577. [Google Scholar]
  15. Hao, X.; Liu, F.; Liu, L.; Wu, H.; Liang, Z.; Zhao, W.; Wang, Y.; Gu, Q.; Kang, B. Zucchini yellow mosaic virus-induced hypersensitive response is associated with pathogenesis-related 1 protein expression and confers resistance in watermelon. Plant Cell Rep. 2024, 43, 277. [Google Scholar] [CrossRef]
  16. Yetışır, H.; Sari, N.; Yücel, S. Rootstock Resistance to Fusarium Wilt and Effect on Watermelon Fruit Yield and Quality. Phytoparasitica 2003, 31, 163–169. [Google Scholar] [CrossRef]
  17. Attavar, A.; Tymon, L.; Perkins-Veazie, P.; Miles, C.A. Cucurbitaceae Germplasm Resistance to Verticillium Wilt and Grafting Compatibility with Watermelon. HortScience 2020, 55, 141–148. [Google Scholar] [CrossRef]
  18. Mahapatra, S.; Rao, E.S.; Hebbar, S.S.; Rao, V.K.; Pitchaimuthu, M.; Sriram, S. Evaluation of rootstocks resistant to gummy stem blight and their effect on the fruit yield and quality traits of grafted watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai). J. Hortic. Sci. Biotechnol. 2023, 98, 635–648. [Google Scholar] [CrossRef]
  19. Mohamed, F.; El-Hamed, K.; Elwan, M.; Hussien, M.-A. Impact of Grafting on Watermelon Growth, Fruit Yield and Quality. Veg. Crops Res. Bull. 2012, 76, 99. [Google Scholar] [CrossRef]
  20. Jang, Y.; Moon, J.-H.; Kim, S.-G.; Kim, T.; Lee, O.-J.; Lee, H.-J.; Wi, S.-H. Effect of Low-Temperature Tolerant Rootstocks on the Growth and Fruit Quality of Watermelon in Semi-Forcing and Retarding Culture. Agronomy 2023, 13, 67. [Google Scholar] [CrossRef]
  21. Thies, J.A.; Ariss, J.J.; Hassell, R.L.; Olson, S.; Kousik, C.S.; Levi, A. Grafting for Management of Southern Root-Knot Nematode, Meloidogyne incognita, in Watermelon. Plant Dis. 2010, 94, 1195–1199. [Google Scholar] [CrossRef] [PubMed]
  22. Pofu, M.; Mashela, P.; Mphosi, M. Management of Meloidogyne incognita in nematodesusceptible watermelon cultivars using nematoderesistant Cucumis africanus and Cucumis myriocarpus rootstocks. Afr. J. Biotechnol. 2011, 10, 8790–8793. [Google Scholar] [CrossRef]
  23. Ellouze, W.; Mishra, V.; Howard, R.J.; Ling, K.-S.; Zhang, W. Preliminary Study on the Control of Cucumber Green Mottle Mosaic Virus in Commercial Greenhouses Using Agricultural Disinfectants and Resistant Cucumber Varieties. Agronomy 2020, 10, 1879. [Google Scholar] [CrossRef]
  24. Yu, T.-A.; Chiang, C.-H.; Wu, H.-W.; Li, C.-M.; Yang, C.-F.; Chen, J.-H.; Chen, Y.-W.; Yeh, S.-D. Generation of Transgenic Watermelon Resistant to Zucchini Yellow Mosaic Virus and Papaya Ringspot Virus type W. Plant Cell Rep. 2011, 30, 359–371. [Google Scholar] [CrossRef]
  25. Lin, C.-Y.; Ku, H.-M.; Chiang, Y.-H.; Ho, H.-Y.; Yu, T.-A.; Jan, F.-J. Development of Transgenic Watermelon Resistant to Cucumber Mosaic Virus and Watermelon Mosaic Virus by Using a Single Chimeric Transgene Construct. Transgenic Res. 2012, 21, 983–993. [Google Scholar] [CrossRef] [PubMed]
  26. Thies, J.A. Grafting for Managing Vegetable Crop Pests. Pest Manag. Sci. 2021, 77, 4825–4835. [Google Scholar] [CrossRef]
  27. Liu, G. Identification and Comprehensive Control of Main Infectious Diseases of Greenhouse Seedless Watermelon in North China. North. Hortic. 2013, 20, 118–120. [Google Scholar]
  28. Qiao, Y.; Wang, Z.; Sun, H.; Guo, H.; Song, Y.; Zhang, H.; Ruan, Y.; Xu, Q.; Huang, Q.; Shen, Q.; et al. Synthetic Community Derived from Grafted Watermelon Rhizosphere Provides Protection for Ungrafted Watermelon Against Fusarium oxysporum via Microbial Synergistic Effects. Microbiome 2024, 12, 101. [Google Scholar] [CrossRef]
  29. Kumar, V.; Mann, S.; Kumar, A. Screening of Vegetables Crop Genotype Against Root-knot Nematode (Meloidogyne incognita) under Polyhouse Conditions. Int. J. Agric. Sci. 2021, 17, 600–603. [Google Scholar] [CrossRef]
  30. Sumita, K.; Vivekananda, Y. A Southern Root-knot Nematode (Meloidogyne incognita) First Reported on Cucumber in Manipur. Indian J. Agric. Res. 2024, 58, 548–550. [Google Scholar] [CrossRef]
  31. Patel, T.; Quesada-Ocampo, L.M.; Wehner, T.C.; Bhatta, B.P.; Correa, E.; Malla, S. Recent Advances and Challenges in Management of Colletotrichum orbiculare, the Causal Agent of Watermelon Anthracnose. Horticulturae 2023, 9, 1132. [Google Scholar] [CrossRef]
  32. Saud, S.; Aryal, S.; Ojha, S.; Bhandari, P.; Ghimire, A.; Thapa, A. A Comprehensive Review: Root-knot Nematode; Biology and Management. Trop. Agroecosyst. 2024, 5, 10–15. [Google Scholar] [CrossRef]
  33. García-Mendívil, H.A.; Munera, M.; Giné, A.; Escudero, N.; Picó, M.B.; Gisbert, C.; Sorribas, F.J. Response of Two Citrullus amarus Accessions to Isolates of Three Species of Meloidogyne and Their Graft Compatibility with Watermelon. Crop Prot. 2019, 119, 208–213. [Google Scholar] [CrossRef]
  34. Phani, V.; Gowda, M.T.; Dutta, T.K. Grafting Vegetable Crops to Manage Plant-parasitic Nematodes: A Review. J. Pest Sci. 2024, 97, 539–560. [Google Scholar] [CrossRef]
  35. Liu, B.; Ren, J.; Zhang, Y.; An, J.; Chen, M.; Chen, H.; Xu, C.; Ren, H. A New Grafted Rootstock Against Root-knot Nematode for Cucumber, Melon, and Watermelon. Agron. Sustain. Dev. 2015, 35, 251–259. [Google Scholar] [CrossRef]
  36. Thies, J.A.; Ariss, J.J.; Kousik, C.S.; Hassell, R.L.; Levi, A. Resistance to Southern Root-knot Nematode (Meloidogyne incognita) in Wild Watermelon (Citrullus lanatus var. citroides). J. Nematol. 2016, 48, 14–19. [Google Scholar] [CrossRef]
  37. Thies, J.; Levi, A.; Ariss, J.; Hassell, R. RKVL-318, a Root-knot Nematode-resistant Watermelon Line as Rootstock for Grafted Watermelon. HortScience 2015, 50, 141–142. [Google Scholar] [CrossRef]
  38. Sehularo, M.N.; Kgwaakgwaa, P.; Madumane, K.; Sewelo, L.T.; Batlang, U.; Kobue-Lekalake, R.; Malambane, G. Grafting Susceptible Watermelon on Wild Watermelon Root Stocks Improves Response to Moisture Stress and Improves Growth and Yield. J. Agric. Sci. 2025, 17. [Google Scholar] [CrossRef]
  39. Rouphael, Y.; Cardarelli, M.; Colla, G.; Rea, E. Yield, Mineral Composition, Water Relations, and Water Use Efficiency of Grafted Mini-watermelon Plants Under Deficit Irrigation. HortScience 2008, 43, 730–736. [Google Scholar] [CrossRef]
  40. Yavuz, N.; Seymen, M.; Yavuz, D.; Kal, Ü.; Kurtar, E.S.; Kal, S.; Gür, A. Functional roles of plant growth-promoting rhizobacteria in ungrafted and grafted watermelons under various deficit irrigation strategies. Agric. Water Manag. 2025, 318, 109687. [Google Scholar] [CrossRef]
  41. Bikdeloo, M.; Colla, G.; Rouphael, Y.; Hassandokht, M.R.; Soltani, F.; Salehi, R.; Kumar, P.; Cardarelli, M. Morphological and Physio-Biochemical Responses of Watermelon Grafted onto Rootstocks of Wild Watermelon [Citrullus colocynthis (L.) Schrad] and Commercial Interspecific Cucurbita Hybrid to Drought Stress. Horticulturae 2021, 7, 359. [Google Scholar] [CrossRef]
  42. Wang, H.; Zhang, W.; Zheng, D.; Li, X.; Hu, X.; Khan, A.; Wang, X.; Li, M.; Du, Q.; Li, J.; et al. Transcription factor ClTCP4 maintains watermelon resilience to drought by stabilizing antioxidant and photosynthetic systems. Plant Cell Rep. 2025, 44, 168. [Google Scholar] [CrossRef]
  43. Huang, Y.; Zhao, L.; Kong, Q.; Cheng, F.; Niu, M.; Xie, J.; Muhammad Azher, N.; Bie, Z. Comprehensive Mineral Nutrition Analysis of Watermelon Grafted onto Two Different Rootstocks. Hortic. Plant J. 2016, 2, 105–113. [Google Scholar] [CrossRef]
  44. Kurtar, E.S.; Seymen, M.; Yavuz, D.; Acar, B.; Metin, D.; Atakul, Z.; Kal, Ü. Morphophysiological and biochemical investigation of the potential of citron watermelon (Citrullus lanatus var. citroides) rootstock under different irrigation regimes. Hortic. Environ. Biotechnol. 2024, 65, 1009–1023. [Google Scholar] [CrossRef]
  45. Yavuz, D.; Gökmen Yılmaz, F.; Seymen, M.; Korkmaz, A.; Baştaş, K.K. Effects of Newly Isolated Rhizobacteria on the Physiological Characteristics and Nutrient Uptake of Watermelon Plants Grafted onto Different Rootstocks Under Water Stress. J. Crop Health 2024, 76, 865–881. [Google Scholar] [CrossRef]
  46. Seymen, M.; Yavuz, D.; Ercan, M.; Akbulut, M.; Çoklar, H.; Kurtar, E.S.; Yavuz, N.; Süheri, S.; Türkmen, Ö. Effect of wild watermelon rootstocks and water stress on chemical properties of watermelon fruit. Hortic. Environ. Biotechnol. 2021, 62, 411–422. [Google Scholar] [CrossRef]
  47. Lu, K.; Sun, J.; Li, Q.; Li, X.; Jin, S. Effect of Cold Stress on Growth, Physiological Characteristics, and Calvin-Cycle-Related Gene Expression of Grafted Watermelon Seedlings of Different Gourd Rootstocks. Horticulturae 2021, 7, 391. [Google Scholar] [CrossRef]
  48. Lu, J.; Cheng, F.; Huang, Y.; Bie, Z. Grafting Watermelon Onto Pumpkin Increases Chilling Tolerance by Up Regulating Arginine Decarboxylase to Increase Putrescine Biosynthesis. Front. Plant Sci. 2022, 12, 812396. [Google Scholar] [CrossRef] [PubMed]
  49. Cheng, F.; Gao, M.; Lu, J.; Huang, Y.; Bie, Z. Spatial–Temporal Response of Reactive Oxygen Species and Salicylic Acid Suggest Their Interaction in Pumpkin Rootstock-Induced Chilling Tolerance in Watermelon Plants. Antioxidants 2021, 10, 2024. [Google Scholar] [CrossRef]
  50. Li, H.; Guo, Y.; Lan, Z.; Xu, K.; Chang, J.; Jalal, A.G.; Ma, J.; Wei, C.; Zhang, X. Methyl Jasmonate Mediates Melatonin-induced Cold Tolerance of Grafted Watermelon Plants. Hortic. Res. 2021, 8, 57. [Google Scholar] [CrossRef] [PubMed]
  51. Wang, Y.; Zhou, J.; Wen, W.; Sun, J.; Shu, S.; Guo, S. Transcriptome and Proteome Analysis Identifies Salt Stress Response Genes in Bottle Gourd Rootstock-Grafted Watermelon Seedlings. Agronomy 2023, 13, 618. [Google Scholar] [CrossRef]
  52. Liu, X.; Guo, S.; Tian, J.; Duan, J.; Du, C. Effects of Grafting on the Isozymes and Activities of Antioxidant Enzymes of Watermelon Leaves under NaCl Stress. J. Chang. Veg. 2009, 4, 22–26. [Google Scholar]
  53. Yang, Y.; Lu, X.; Yan, B.; Li, B.; Sun, J.; Guo, S.; Tezuka, T. Bottle Gourd Rootstock-grafting Affects Nitrogen Metabolism in NaCl-stressed Watermelon Leaves and Enhances Short-term Salt Tolerance. J. Plant Physiol. 2013, 170, 653–661. [Google Scholar] [CrossRef]
  54. Yang, Y.; Wang, L.; Tian, J.; Li, J.; Sun, J.; He, L.; Guo, S.; Tezuka, T. Proteomic Study Participating the Enhancement of Growth and Salt Tolerance of Bottle Gourd Rootstock-grafted Watermelon Seedlings. Plant Physiol. Biochem. 2012, 58, 54–65. [Google Scholar] [CrossRef]
  55. Yetisir, H.; Uygur, V. Responses of Grafted Watermelon onto Different Gourd Species to Salinity Stress. J. Plant Nutr. 2010, 33, 315–327. [Google Scholar] [CrossRef]
  56. Yan, Y.; Wang, S.; Wei, M.; Gong, B.; Shi, Q. Effect of Different Rootstocks on the Salt Stress Tolerance in Watermelon Seedlings. Hortic. Plant J. 2018, 4, 239–249. [Google Scholar] [CrossRef]
  57. Zhu, H.; Zhao, S.; Lu, X.; He, N.; Gao, L.; Dou, J.; Bie, Z.; Liu, W. Genome Duplication Improves the Resistance of Watermelon Root to Salt Stress. Plant Physiol. Biochem. 2018, 133, 11–21. [Google Scholar] [CrossRef]
  58. Bőhm, V.; Fekete, D.; Balázs, G.; Gáspár, L.; Kappel, N. Salinity Tolerance of Grafted Watermelon Seedlings. Acta Biol. Hung. 2017, 68, 412–427. [Google Scholar] [CrossRef]
  59. Yang, Y.; Guo, S.; Li, J.; Du, C.; Chen, L.; Wang, L. Effects of Grafting on the Soluble Protein Expression in Watermelon Seedling under Salt Stress. J. Nanjing Agric. Univ. 2011, 34, 54–60. [Google Scholar]
  60. Márkus, R.; Czigle, S.; Zana, B.; Somogyi, B.A.; Urbán, P.; Kutyáncsánin, D.; Helfrich, P.; Stranczinger, S. Drought and Salt Stressors Alter NAC and WRKY Gene Expression Profiles in Grafted Citrullus lanatus. Plant Mol. Biol. Report. 2025, 43, 1576–1587. [Google Scholar] [CrossRef]
  61. Chen, S.; Zhong, K.; Li, Y.; Bai, C.; Xue, Z.; Wu, Y. Joint transcriptomic and metabolomic analysis provides new insights into drought resistance in watermelon (Citrullus lanatus). Front. Plant Sci. 2024, 15, 1364631. [Google Scholar] [CrossRef] [PubMed]
  62. Korkmaz, A.; Dufault, R. Short-term Cyclic Cold Temperature Stress on Watermelon Yield. HortScience 2002, 37, 487–489. [Google Scholar] [CrossRef]
  63. Yaseen, I.; Choi, S.; Mukhtar, T.; Park, J.-I.; Kim, H.-T. Quantification of Growth and Physiological Characteristics in Tolerant and Sensitive Watermelon Lines Under Cold Treatment. Hortic. Environ. Biotechnol. 2025, 66, 189–204. [Google Scholar] [CrossRef]
  64. Xu, J.; Zhang, M.; Liu, G.; Yang, X.; Hou, X. Comparative Transcriptome Profiling of Chilling Stress Responsiveness in Grafted Watermelon Seedlings. Plant Physiol. Biochem. 2016, 109, 561–570. [Google Scholar] [CrossRef]
  65. Hou, L.; Yin, J.; Wu, L.; Yan, J.; Guo, Q.; XIan, W. Transcriptome Analysis Revealed that Grafting Improves the Resistance of Pepper to Phytophthora Capsici by Fine-tuning Growth-defense Tradeoff. Not. Bot. Horti Agrobot. Cluj-Napoca 2022, 50, 12705. [Google Scholar] [CrossRef]
  66. Lang, X.; Zhao, X.; Zhao, J.; Ren, T.; Nie, L.; Zhao, W. MicroRNA Profiling Revealed the Mechanism of Enhanced Cold Resistance by Grafting in Melon (Cucumis melo L.). Plants 2024, 13, 1016. [Google Scholar] [CrossRef]
  67. Smiti, K.; Mina, U.; Verma, M.; Arya, L. Impact of Climate Extremes and Other Key Abiotic Stresses on Cucurbits: A Systematic Review. Vegetos 2025. [Google Scholar] [CrossRef]
  68. Bayoumi, Y.; Abd-Alkarim, E.; El-Ramady, H.; El-Aidy, F.; Hamed, E.-S.; Taha, N.; Prohens, J.; Rakha, M. Grafting Improves Fruit Yield of Cucumber Plants Grown under Combined Heat and Soil Salinity Stresses. Horticulturae 2021, 7, 61. [Google Scholar] [CrossRef]
  69. El-Kafafi, S.; Abu El-Azm, N.; Hikal, M. Grafting Enables Cantaloupe to Tolerate More Saline Stress. J. Plant Prod. 2017, 8, 671–678. [Google Scholar] [CrossRef]
  70. Song, Q.; Joshi, M.; Joshi, V. Transcriptomic Analysis of Short-Term Salt Stress Response in Watermelon Seedlings. Int. J. Mol. Sci. 2020, 21, 6036. [Google Scholar] [CrossRef]
  71. Sun, X.; Chen, S.; Yang, L.; Li, J.; Zhou, B.; Chen, N. Effects of Salt Stress on Plant Growth and Stoichiometric Characteristics of C, N, P and K of Grafted Watermelon Seedlings. Agric. Res. Arid. Areas 2020, 38, 170–176. [Google Scholar]
  72. Zhu, Y.; Yuan, G.; Gao, B.; An, G.; Li, W.; Si, W.; Sun, D.; Liu, J. Comparative Transcriptome Profiling Provides Insights into Plant Salt Tolerance in Watermelon (Citrullus lanatus). Life 2022, 12, 1033. [Google Scholar] [CrossRef]
  73. Liu, Y.; Zhang, W.; Elango, D.; Liu, H.; Jin, D.; Wang, X.; Wu, Y. Metabolome and Transcriptome Analysis Reveals Molecular Mechanisms of Watermelon under Salt Stress. Environ. Exp. Bot. 2023, 206, 105200. [Google Scholar] [CrossRef]
  74. Llanderal, A.; Vasquez Muñoz, G.; Pincay-Solorzano, M.S.; Ceasar, S.A.; García-Caparros, P. Growth, Spectral Vegetation Indices, and Nutritional Performance of Watermelon Seedlings Subjected to Increasing Salinity Levels. Agronomy 2025, 15, 1620. [Google Scholar] [CrossRef]
  75. Niu, M.; Luo, W.; Luo, L.; Chen, S.; Zhao, H.; Zhang, H.; Qian, Y. Non-Invasive Micro-Test Technology and Reciprocal Grafting Provide Direct Evidence of Contrasting Na+ Transport Strategies between Cucurbita moschata and Cucurbita maxima. Agronomy 2023, 13, 1843. [Google Scholar] [CrossRef]
  76. Başak, H.; Aydin, A.; Yetişir, H.; Turan, M. Salt Stress Effects On Hybrid Bottle Gourd (Lagenaria siceraria) Rootstock Candidates Plant Growth, Hormones and Nutrient Content. J. Crop Health 2025, 77, 28. [Google Scholar] [CrossRef]
  77. Yuan, G.; He, Y.; Sun, D.; Shi, M.; Li, W.; Zhang, J.; Zhu, Y. ClaDREB14 Enhances the Salt Tolerance of Watermelon by Positively Regulating the Expression of ClaPOD6. Hortic. Plant J. 2025. [Google Scholar] [CrossRef]
  78. Kyriacou, M.C.; Leskovar, D.I.; Colla, G.; Rouphael, Y. Watermelon and Melon Fruit Quality: The Genotypic and Agro-environmental Factors Implicated. Sci. Hortic. 2018, 234, 393–408. [Google Scholar] [CrossRef]
  79. Dia, M.; Wehner, T.C.; Perkins-Veazie, P.; Hassell, R.; Price, D.S.; Boyhan, G.E.; Olson, S.M.; King, S.R.; Davis, A.R.; Tolla, G.E. Stability of Fruit Quality Traits in Diverse Watermelon Cultivars Tested in Multiple Environments. Hortic. Res. 2016, 3, 16066. [Google Scholar] [CrossRef] [PubMed]
  80. Ying, Q.; He, Y.; Wang, Y.; Cao, T.; Gu, B.; Wang, Y. Effects of Grafting with Different Rootstocks on Watermelon Fruit Quality. Acta Agric. Zhejiangensis 2017, 29, 590–596. [Google Scholar]
  81. Sun, N.; Ma, Y.; Wang, X.; Ying, Q.; Huang, Y.; Zhang, L.; Zhu, Z.; Wang, Y.; He, Y. Grafting onto Pumpkin Alters the Evolution of Fruit Sugar Profile and Increases Fruit Weight through Invertase and Sugar Transporters in Watermelon. Sci. Hortic. 2023, 314, 111936. [Google Scholar] [CrossRef]
  82. Soteriou, G.A.; Kyriacou, M.C.; Siomos, A.S.; Gerasopoulos, D. Evolution of Watermelon Fruit Physicochemical and Phytochemical Composition during Ripening as Affected by Grafting. Food Chem. 2014, 165, 282–289. [Google Scholar] [CrossRef]
  83. Liu, Q.; Zhao, X.; Brecht, J.K.; Sims, C.A.; Sanchez, T.; Dufault, N.S. Fruit Quality of Seedless Watermelon Grafted onto Squash Rootstocks under Different Production Systems. J. Sci. Food Agric. 2017, 97, 4704–4711. [Google Scholar] [CrossRef] [PubMed]
  84. Garcia-Lozano, M.; Dutta, S.K.; Natarajan, P.; Tomason, Y.R.; Lopez, C.; Katam, R.; Levi, A.; Nimmakayala, P.; Reddy, U.K. Transcriptome Changes in Reciprocal Grafts Involving Watermelon and Bottle Gourd Reveal Molecular Mechanisms Involved in Increase of the Fruit SIze, RInd Toughness and Soluble Solids. Plant Mol. Biol. 2020, 102, 213–223. [Google Scholar] [CrossRef]
  85. Ning, K.; Cai, X.; Yan, L.; Zhou, W.; Xie, A.; Wang, Y.; Xu, P. Transcriptomic and Metabolomic Analysis Reveals Improved Fruit Quality in Grafted Watermelon. Horticulturae 2024, 10, 1269. [Google Scholar] [CrossRef]
  86. Aslam, A.; Zhao, S.; Azam, M.; Lu, X.; He, N.; Li, B.; Dou, J.; Zhu, H.; Liu, W. Comparative Analysis of Primary Metabolites and Transcriptome Changes Between Ungrafted and Pumpkin-grafted Watermelon During Fruit Development. PeerJ 2020, 8, e8259. [Google Scholar] [CrossRef]
  87. Fekete, D.; Stéger-Máté, M.; Bőhm, V.; Balázs, G.; Kappel, N. Lycopene and Flesh Colour Differences in Grafted and Non-grafted Watermelon. Acta Univ. Sapientiae Aliment. 2015, 8, 111–117. [Google Scholar] [CrossRef]
  88. Kong, Q.; Yuan, J.; Gao, L.; Liu, P.; Cao, L.; Huang, Y.; Zhao, L.; Lv, H.; Bie, Z. Transcriptional Regulation of Lycopene Metabolism Mediated by Rootstock During the Ripening of Grafted Watermelons. Food Chem. 2017, 214, 406–411. [Google Scholar] [CrossRef] [PubMed]
  89. Kyriacou, M.C.; Soteriou, G.A.; Rouphael, Y.; Siomos, A.S.; Gerasopoulos, D. Configuration of Watermelon Fruit Quality in Response to Rootstock-Mediated Harvest Maturity and Postharvest Storage. J. Sci. Food Agric. 2016, 96, 2400–2409. [Google Scholar] [CrossRef]
  90. Guo, S.; Sun, H.; Tian, J.; Zhang, G.; Gong, G.; Ren, Y.; Zhang, J.; Li, M.; Zhang, H.; Li, H.; et al. Grafting Delays Watermel on Fruit Ripening by Altering Gene Expression of ABA Centric Phytohormone Signaling. Front. Plant Sci. 2021, 12, 624319. [Google Scholar] [CrossRef]
  91. Davis, A.R.; Perkins-Veazie, P. Rootstock Effects on Plant Vigor and Watermelon Fruit Quality. Rep.-Cucurbit Genet. Coop. 2005, 28, 39. [Google Scholar]
  92. Soteriou, G.A.; Siomos, A.S.; Gerasopoulos, D.; Rouphael, Y.; Georgiadou, S.; Kyriacou, M.C. Biochemical and Histological Contributions to Textural Changes in Watermelon Fruit Modulated by Grafting. Food Chem. 2017, 237, 133–140. [Google Scholar] [CrossRef] [PubMed]
  93. Kyriacou, M.C.; Soteriou, G. Quality and Postharvest Performance of Watermelon Fruit in Response to Grafting on Interspecific Cucurbit Rootstocks. J. Food Qual. 2015, 38, 21–29. [Google Scholar] [CrossRef]
  94. Kurum, R.; Çelik, İ.; Eren, A. Effects of Rootstocks on Fruit Yield and Some Quality Traits of Watermelon (Citrullus lanatus). Derim 2017, 34, 91–98. [Google Scholar] [CrossRef]
  95. Fredes, A.; Roselló, S.; Beltran Arandes, J.; Cebolla-Cornejo, J.; Pérez de Castro, A.; Gisbert, P.; Picó, M.B. Fruit Quality Assessment of Watermelons Grafted onto Citron Melon Rootstock. J. Sci. Food Agric. 2017, 97, 1646–1655. [Google Scholar] [CrossRef]
  96. Zaaroor-Presman, M.; Alkalai-Tuvia, S.; Chalupowicz, D.; Beniches, M.; Gamliel, A.; Fallik, E. Watermelon Rootstock/Scion Relationships and the Effects of Fruit-Thinning and Stem-Pruning on Yield and Postharvest Fruit Quality. Agriculture 2020, 10, 366. [Google Scholar] [CrossRef]
  97. Aras, V.; Sari, N.; Solmaz, I. Effects of Cucurbita, Lagenaria and Citrullus rootstocks on pollen and fruit characters, seed yield and quality of F 1 hybrid watermelon. Int. J. Agric. Environ. Food Sci. 2022, 6, 683–693. [Google Scholar] [CrossRef]
  98. Chen, W.; Zhong, C.; Liao, J.; Bao, W.; Yang, Y.; Yu, W. Effects of Double-rootstock Grafting on Growth and Fruit Quality of Watermelon. China Cucurbits Veg. 2017, 30, 13–16. [Google Scholar]
  99. Ning, K.; Zhou, W.; Cai, X.; Yan, L.; Ma, Y.; Xie, A.; Wang, Y.; Xu, P. Rootstock–Scion Exchanging mRNAs Participate in Watermelon Fruit Quality Improvement. Int. J. Mol. Sci. 2025, 26, 5121. [Google Scholar] [CrossRef] [PubMed]
  100. Gölükcü, M.; Tokgöz, H. Variation in Sugar, Organic Acid and Volatile Flavor Compounds of Watermelon (Citrullus lanatus) Grafted on Different Rootstocks at Different Harvest Time. Akad. Gıda 2018, 16, 381–386. [Google Scholar] [CrossRef]
  101. Liu, J.; Li, J. Grafting Experiment with Different Stocks on Watermelon and Muskmelon. North. Hortic. 2008, 1, 33–35. [Google Scholar]
  102. Gao, L.; Zhao, S.; Lu, X.; He, N.; Zhu, H.; Dou, J.; Liu, W. Comparative Transcriptome Analysis Reveals Key Genes Potentially Related to Soluble Sugar and Organic Acid Accumulation in Watermelon. PLoS ONE 2018, 13, e0190096. [Google Scholar] [CrossRef] [PubMed]
  103. Umer, M.J.; Bin Safdar, L.; Gebremeskel, H.; Zhao, S.; Yuan, P.; Zhu, H.; Kaseb, M.O.; Anees, M.; Lu, X.; He, N.; et al. Identification of Key Gene Networks Controlling Organic Acid and Sugar Metabolism during Watermelon Fruit Development by Integrating Metabolic Phenotypes and Gene Expression Profiles. Hortic. Res. 2020, 7, 193. [Google Scholar] [CrossRef]
  104. Li, Y.; Cui, Z.; Hu, L. Recent Technological Strategies for Enhancing the Stability of Lycopene in Processing and Production. Food Chem. 2023, 405, 134799. [Google Scholar] [CrossRef] [PubMed]
  105. Edwards, A.J.; Wiley, E.R.; Brown, E.D.; Clevidence, B.A.; Vinyard, B.T.; Collins, J.K.; Perkins-Veazie, P.; Baker, R.A. Consumption of Watermelon Juice Increases Plasma Concentrations of Lycopene and β-Carotene in Humans. J. Nutr. 2003, 133, 1043–1050. [Google Scholar] [CrossRef] [PubMed]
  106. Liu, W.; He, N.; Zhao, S.; Lu, X. Advances in Watermelon Breeding in China. China Cucurbits Veg. 2016, 29, 1–7. [Google Scholar] [CrossRef]
  107. Shafe, M.O.; Gumede, N.M.; Nyakudya, T.T.; Chivandi, E. Lycopene: A Potent Antioxidant with Multiple Health Benefits. J. Nutr. Metab. 2024, 2024, 6252426. [Google Scholar] [CrossRef]
  108. Noreen, S.; Shehzadi, S.; Egbuna, C.; Aja, P.M. Lycopene Alleviates Lipid Dysregulation, Oxidative Stress, and Hypercholesterolemia in Obese Rats Subjected to a High-Fat Diet. Food Sci. Nutr. 2025, 13, e70549. [Google Scholar] [CrossRef]
  109. Tripathi, A.K.; Das, R.; Ray, A.K.; Mishra, S.K.; Anand, S. Recent Insights on Pharmacological Potential of Lycopene and its Nanoformulations: An Emerging Paradigm towards Improvement of Human Health. Phytochem. Rev. 2025, 24, 1091–1118. [Google Scholar] [CrossRef]
  110. Perkins Veazie, P.; Olson, S.; Hassell, R.; Schultheis, J.; Miller, G.; Kelly, W. Rootstock of Interspecific Squash Hybrids (Cucarbita maxima x Cucurbita moschata) Increases Lycopene Content of Watermelon. In Proceedings of the HortScience, Orlando, FL, USA, 21–24 July 2008; pp. 1199–1200. [Google Scholar]
  111. Xu, X.; Bie, Z.; Sun, D.; Deng, Y.; Li, W.; An, G.; Liu, J. Effects of Grafting Combinations on the Plant Growth and Fruit Quality in Watermelon (Citrullus lanatus). China Cucurbits Veg. 2011, 24, 10–14. [Google Scholar] [CrossRef]
  112. Roberts, W.; Bruton, B.; Fish, W.; Taylor, M. Year Two: Effects of Grafting on Watermelon Yield and Quality. HortScience 2006, 41, 519. [Google Scholar] [CrossRef]
  113. Alan, O.; Ozdemir, N.; Gunen, Y. Effect of Grafting on Watermelon Plant Growth, Yield and Quality. J. Agron. 2007, 6, 362–365. [Google Scholar] [CrossRef]
  114. Fallik, E.; Alkalai-Tuvia, S.; Chalupowicz, D.; Popovsky-Sarid, S.; Zaaroor-Presman, M. Relationships between Rootstock-Scion Combinations and Growing Regions on Watermelon Fruit Quality. Agronomy 2019, 9, 536. [Google Scholar] [CrossRef]
  115. Devi, P.; Perkins-Veazie, P.; Miles, C. Impact of Grafting on Watermelon Fruit Maturity and Quality. Horticulturae 2020, 6, 97. [Google Scholar] [CrossRef]
  116. Louws, F.J.; Rivard, C.L.; Kubota, C. Grafting Fruiting Vegetables to Manage Soilborne Pathogens, Foliar Pathogens, Arthropods and Weeds. Sci. Hortic. 2010, 127, 127–146. [Google Scholar] [CrossRef]
  117. Mozafarian Meimandi, M.; Kappel, N. Grafting Plants to Improve Abiotic Stress Tolerance. In Plant Ecophysiology and Adaptation under Climate Change: Mechanisms and Perspectives II: Mechanisms of Adaptation and Stress Amelioration; Hasanuzzaman, M., Ed.; Springer: Singapore, 2020; pp. 477–490. [Google Scholar]
  118. Lu, X.; Liu, W.; Wang, T.; Zhang, J.; Li, X.; Zhang, W. Systemic Long-Distance Signaling and Communication Between Rootstock and Scion in Grafted Vegetables. Front. Plant Sci. 2020, 11, 460. [Google Scholar] [CrossRef] [PubMed]
  119. Tsutsui, H.; Notaguchi, M. The Use of Grafting to Study Systemic Signaling in Plants. Plant Cell Physiol. 2017, 58, 1291–1301. [Google Scholar] [CrossRef] [PubMed]
  120. Jin, Q.; Chachar, M.; Ahmed, N.; Zhang, P.; Chachar, Z.; Geng, Y.; Guo, D.; Chachar, S. Harnessing Epigenetics through Grafting: Revolutionizing Horticultural Crop Production. Horticulturae 2023, 9, 672. [Google Scholar] [CrossRef]
  121. Habibi, F.; Liu, T.; Folta, K.; Sarkhosh, A. Physiological, biochemical, and molecular aspects of grafting in fruit trees. Hortic. Res. 2022, 9, uhac032. [Google Scholar] [CrossRef]
  122. Lal, N.; Ramteke, V.; Diwan, G.; Singh, P.; Sahu, N.; Hota, D.; S.R., M.; Meena, N.K.; Sharma, K.M.; Shiurkar, G.B.; et al. Physiological, Biochemical, and Molecular Responses During Grafting in Horticultural Crops. Plant Mol. Biol. Report. 2025. [Google Scholar] [CrossRef]
  123. Dong, D.; Shi, Y.-N.; Mou, Z.-M.; Chen, S.-Y.; Zhao, D.-K. Grafting: A potential method to reveal the differential accumulation mechanism of secondary metabolites. Hortic. Res. 2022, 9, uhac050. [Google Scholar] [CrossRef] [PubMed]
  124. Bozorov, T.A.; Dinh, S.T.; Baldwin, I.T. JA but not JA-Ile is the cell-nonautonomous signal activating JA mediated systemic defenses to herbivory in Nicotiana attenuata. J. Integr. Plant Biol. 2017, 59, 552–571. [Google Scholar] [CrossRef]
  125. Fu, Z.Q.; Dong, X. Systemic Acquired Resistance: Turning Local Infection into Global Defense. Annu. Rev. Plant Biol. 2013, 64, 839–863. [Google Scholar] [CrossRef]
  126. Mou, Z.; Fan, W.; Dong, X. Inducers of Plant Systemic Acquired Resistance Regulate NPR1 Function through Redox Changes. Cell 2003, 113, 935–944. [Google Scholar] [CrossRef]
  127. Tonelli, M.L.; Figueredo, M.S.; Rodríguez, J.; Fabra, A.; Ibañez, F. Induced systemic resistance -like responses elicited by rhizobia. Plant Soil 2020, 448, 1–14. [Google Scholar] [CrossRef]
  128. Kushalappa, A.C.; Yogendra, K.N.; Karre, S. Plant Innate Immune Response: Qualitative and Quantitative Resistance. Crit. Rev. Plant Sci. 2016, 35, 38–55. [Google Scholar] [CrossRef]
  129. Rabari, A.; Ruparelia, J.; Jha, C.K.; Sayyed, R.Z.; Mitra, D.; Priyadarshini, A.; Senapati, A.; Panneerselvam, P.; Das Mohapatra, P.K. Articulating beneficial rhizobacteria-mediated plant defenses through induced systemic resistance: A review. Pedosphere 2023, 33, 556–566. [Google Scholar] [CrossRef]
  130. Khan, R.A.A.; Najeeb, S.; Chen, J.; Wang, R.; Zhang, J.; Hou, J.; Liu, T. Insights into the molecular mechanism of Trichoderma stimulating plant growth and immunity against phytopathogens. Physiol. Plant. 2023, 175, e14133. [Google Scholar] [CrossRef]
  131. Wu, G.; Liu, Y.; Xu, Y.; Zhang, G.; Shen, Q.; Zhang, R. Exploring Elicitors of the Beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 to Induce Plant Systemic Resistance and Their Interactions With Plant Signaling Pathways. Mol. Plant-Microbe Interact. 2018, 31, 560–567. [Google Scholar] [CrossRef]
  132. Kapazoglou, A.; Tani, E.; Avramidou, E.V.; Abraham, E.M.; Gerakari, M.; Megariti, S.; Doupis, G.; Doulis, A.G. Epigenetic Changes and Transcriptional Reprogramming Upon Woody Plant Grafting for Crop Sustainability in a Changing Environment. Front. Plant Sci. 2021, 11, 613004. [Google Scholar] [CrossRef]
  133. Cerruti, E.; Gisbert, C.; Drost, H.-G.; Valentino, D.; Portis, E.; Barchi, L.; Prohens, J.; Lanteri, S.; Comino, C.; Catoni, M. Grafting vigour is associated with DNA de-methylation in eggplant. Hortic. Res. 2021, 8, 241. [Google Scholar] [CrossRef]
  134. Liu, J.; Li, J.; Su, X.; Xia, Z. Grafting improves drought tolerance by regulating antioxidant enzyme activities and stress-responsive gene expression in tobacco. Environ. Exp. Bot. 2014, 107, 173–179. [Google Scholar] [CrossRef]
  135. Monteiro, G.C.; Goto, R.; Minatel, I.O.; de Sousa da Silva, E.; da Silva, E.G.; Vianello, F.; Lima, G.P.P. Grafting, Agrochemicals, and Oxidative Enzymes as Factor for Plant Biotic Resistance. In Plant Health Under Biotic Stress: Volume 1: Organic Strategies; Ansari, R.A., Mahmood, I., Eds.; Springer: Singapore, 2019; pp. 37–57. [Google Scholar]
  136. Liu, Y.; Liu, H.; Zhang, T.; Liu, J.; Sun, X.; Sun, X.; Wang, W.; Zheng, C. Interactions Between Rootstock and Scion during Grafting and Their Molecular Rgulation Mechanism. Sci. Hortic. 2023, 308, 111554. [Google Scholar] [CrossRef]
  137. Williams, B.; Ahsan, M.U.; Frank, M.H. Getting to the root of grafting-induced traits. Curr. Opin. Plant Biol. 2021, 59, 101988. [Google Scholar] [CrossRef]
  138. Nawaz, M.A.; Imtiaz, M.; Kong, Q.; Cheng, F.; Ahmed, W.; Huang, Y.; Bie, Z. Grafting: A Technique to Modify Ion Accumulation in Horticultural Crops. Front. Plant Sci. 2016, 7, 1457. [Google Scholar] [CrossRef]
  139. Fullana-Pericàs, M.; Conesa, M.À.; Pérez-Alfocea, F.; Galmés, J. The influence of grafting on crops’ photosynthetic performance. Plant Sci. 2020, 295, 110250. [Google Scholar] [CrossRef]
  140. Coşkun, Ö.F. The Effect of Grafting on Morphological, Physiological and Molecular Changes Induced by Drought Stress in Cucumber. Sustainability 2023, 15, 875. [Google Scholar] [CrossRef]
  141. Jiao, S.; Zeng, F.; Huang, Y.; Zhang, L.; Mao, J.; Chen, B. Physiological, biochemical and molecular responses associated with drought tolerance in grafted grapevine. BMC Plant Biol. 2023, 23, 110. [Google Scholar] [CrossRef] [PubMed]
  142. Nadoda, N.A.; Barot, D.C.; Baria, V.K.; Chaudhari, V.M. Exploitation of Grafting for Abiotic and Biotic Stress Management in Vegetable Crops: A Review. Adv. Res. Teach. 2024, 25, 125–131. [Google Scholar] [CrossRef]
  143. Wang, X.; Cao, M.; Li, H.; Liu, Y.; Fan, S.; Zhang, N.; Guo, Y. Strategies and prospects for melatonin to alleviate abiotic stress in horticultural plants. Hortic. Plant J. 2024, 10, 601–614. [Google Scholar] [CrossRef]
  144. Siddique, A.B.; Parveen, S.; Rahman, M.Z.; Rahman, J. Revisiting plant stress memory: Mechanisms and contribution to stress adaptation. Physiol. Mol. Biol. Plants 2024, 30, 349–367. [Google Scholar] [CrossRef]
  145. Davoudi, M.; Song, M.; Zhang, M.; Chen, J.; Lou, Q. Long-distance control of the scion by the rootstock under drought stress as revealed by transcriptome sequencing and mobile mRNA identification. Hortic. Res. 2022, 9, uhab033. [Google Scholar] [CrossRef]
  146. Lin, J. Molecular Mechanisms of Plant Response to Abiotic Stresses and Breeding for Stress Tolerance. Theor. Nat. Sci. 2024, 63, 123–127. [Google Scholar] [CrossRef]
  147. Tsaballa, A.; Xanthopoulou, A.; Madesis, P.; Tsaftaris, A.; Nianiou-Obeidat, I. Vegetable Grafting From a Molecular Point of View: The Involvement of Epigenetics in Rootstock-Scion Interactions. Front. Plant Sci. 2021, 11, 621999. [Google Scholar] [CrossRef]
  148. Apostolova, E.L. Molecular Mechanisms Associated with Plant Tolerance upon Abiotic Stress. Plants 2024, 13, 3532. [Google Scholar] [CrossRef]
  149. Qi, W.; Zhang, C.; Wang, W.; Cao, Z.; Li, S.; Li, H.; Zhu, W.; Huang, Y.; Bao, M.; He, Y.; et al. Comparative transcriptome analysis of different heat stress responses between self-root grafting line and heterogeneous grafting line in rose. Hortic. Plant J. 2021, 7, 243–255. [Google Scholar] [CrossRef]
  150. Lu, X.; Liu, Y.; Xu, J.; Liu, X.; Chi, Y.; Li, R.; Mo, L.; Shi, L.; Liang, S.; Yu, W.; et al. Recent progress of molecular mechanisms of DNA methylation in plant response to abiotic stress. Environ. Exp. Bot. 2024, 218, 105599. [Google Scholar] [CrossRef]
  151. Fuentes-Merlos, M.I.; Bamba, M.; Sato, S.; Higashitani, A. Self-grafting-induced Epigenetic Changes Leading to Drought Stress Tolerance in Tomato Plants. DNA Res. 2023, 30, dsad016. [Google Scholar] [CrossRef] [PubMed]
  152. Khalid, F.; Rasheed, Y.; Asif, K.; Ashraf, H.; Maqsood, M.F.; Shahbaz, M.; Zulfiqar, U.; Sardar, R.; Haider, F.U. Plant Biostimulants: Mechanisms and Applications for Enhancing Plant Resilience to Abiotic Stresses. J. Soil Sci. Plant Nutr. 2024, 24, 6641–6690. [Google Scholar] [CrossRef]
  153. Morcillo, R.; Manzanera, M. The Effects of Plant-Associated Bacterial Exopolysaccharides on Plant Abiotic Stress Tolerance. Metabolites 2021, 11, 337. [Google Scholar] [CrossRef] [PubMed]
  154. Morais, M.C.; Torres, L.F.; Kuramae, E.E.; Andrade, S.A.L.d.; Mazzafera, P. Plant Gafting: Maximizing Beneficial Microbe-plant Interactions. Rhizosphere 2024, 29, 100825. [Google Scholar] [CrossRef]
Horticulturae 11 01271 g001
Figure 1. The main steps of watermelon grafting and suitable grafting methods. (A) Watermelon seedling was used as scion. (B) Rootstock seedling. (C) Grafted watermelon seedling after the process. (D–F) represent the three commonly used grafting methods suitable for watermelon. (D) Top-insertion grafting: A sharp tool is used to pierce the stem at the growing point of the rootstock without penetrating it. The scion is then inserted, positioning the cotyledons of the scion and rootstock in a cross shape relative to each other. (E) Cleft grafting: A blade is used to make a vertical incision approximately 1–1.5 cm long at the growing point of the rootstock. The scion is inserted into the incision and secured using a grafting clip or tube. (F) Approach grafting: After removing the growing point of the rootstock, a downward incision of approximately 1 cm in length was made with a blade. The scion was prepared with an upward slanting cut of approximately 1 cm. The scion and rootstock are then fitted together and secured with grafting clips or tubes. The red rectangles in the figure indicate the positions of the graft clips or tubes.
Figure 1. The main steps of watermelon grafting and suitable grafting methods. (A) Watermelon seedling was used as scion. (B) Rootstock seedling. (C) Grafted watermelon seedling after the process. (D–F) represent the three commonly used grafting methods suitable for watermelon. (D) Top-insertion grafting: A sharp tool is used to pierce the stem at the growing point of the rootstock without penetrating it. The scion is then inserted, positioning the cotyledons of the scion and rootstock in a cross shape relative to each other. (E) Cleft grafting: A blade is used to make a vertical incision approximately 1–1.5 cm long at the growing point of the rootstock. The scion is inserted into the incision and secured using a grafting clip or tube. (F) Approach grafting: After removing the growing point of the rootstock, a downward incision of approximately 1 cm in length was made with a blade. The scion was prepared with an upward slanting cut of approximately 1 cm. The scion and rootstock are then fitted together and secured with grafting clips or tubes. The red rectangles in the figure indicate the positions of the graft clips or tubes.
Horticulturae 11 01271 g001
Table 1. Effects of grafting on biotic stress resistance of watermelon.
Table 1. Effects of grafting on biotic stress resistance of watermelon.
Type of StressRootstockScionResistanceReferences
VirusCucurbita maxima × C. moschataRS841,
Shintosa Camelforce		Tri-X 313Increased yield; fruit firmness increased, but did not affect the soluble solids content.[13]
Cucurbita maxima × C. moschataRS-841, ErcoleMielheartSignificantly increased the resistance of scions to MNSV.[14]
Citrullus lanatus var citroidesRobust
Citrullus mucosospermus938-16-B938-16-B, H1, HongziResistant to virus disease.[15]
Citrullus lanatusH1, HongziSusceptible to viral diseases.
FungusCucurbita moschataLandraceCrimson TideThe incidence rate was reduced by 88–100%, and even completely controlled.[16]
Cucurbita maximaLandrace
Lagenaria sicerariaLandrace
Luffa cylindricaLandrace
Benincasa hispidaLandrace
Lagenaria hybrid216, Emphasis,
Skopje, FR Gold
Cucurbita hybridP360, Strong Tosa
Lagenaria sicerariaUSVL482-PMR, USVL351-PMRMickey LeeSignificantly enhance the resistance of the scion to powdery mildew.[7]
Lagenaria sicerariaChaofengkangshengwangSumi 1High resistance to Fusarium wilt, and the incidence was only 3.4%.[6]
Cucurbita maxima × C. moschataTetsukabutoSecretariatResistance to verticillium wilt.[17]
Citrullus lanatus var. citroidesIIHR-82, IIHR-617,
BIL-53		NS-295Resistance to gummy stem blight.[18]
Lagenaria sicerariaBG-95, BG-77-6-1
Citrullus lanatus var. citroidesIIHR-617 × Arka Manik, IIHR-82 × Arka Manik, IIHR-82 × IIHR-617
Cucurbita maxima × C. moschataNun 6001, Strongtosa,
Tetsukabuto, Ferro,
Shintoza		Aswan F1Enhance disease resistance.[19]
Lagenaria sicerariaIT207112SambokkulResistance to Fusarium wilt, single spore root rot, and vine recession.[20]
Lagenaria sicerariaFRD22Moderate resistance to single spore root rot and vine decline disease.
NematodesLagenaria sicerariaEmphasis, WMXP 3938,
WMXP 3944,
WMXP3445		Fiesta, Tri-X 313Significantly reduce the root knot rate and infection level; increase production.[21]
Cucurbita moschata × C. maximaStrong TosaSignificant nematode resistance in field trials.
Citrullus lanatus var. citroidesRKVL 301, RKVL 302, RKVL 303, RKVL 315, RKVL 318, OjakkyoSignificant resistance; root knot index and nematode reproduction were low.
Cucumis africanus,
Cucumis myriocarpus		Congo, Charleston GrayResistance to root-knot nematodes.[22]
Table 2. Effects of grafting on abiotic stress resistance of watermelon.
Table 2. Effects of grafting on abiotic stress resistance of watermelon.
Type of StressRootstockScionResistanceReferences
Drought stressLagenaria sicerariaIllapel, Osorno,
GC		Santa AmeliaDrought tolerance, significantly increased yield; improve root structure.[10]
BG-48, PhilippinesNot drought-tolerant.
Cucurbita maxima × C. moschataShintozaCrimson SweetBetter growth performance and water status.[41]
Citrullus colocynthis (L.) SchradEsfahanBetter drought resistance, growth and biomass decreased less, and showed higher antioxidant activity and lower oxidative stress.
Cucurbita moschataNaihan 1 Up-regulation of ClTCP4 gene expression in scions helped to maintain higher photosynthetic efficiency and cell membrane stability.[42]
Lagenaria sicerariaJingxinzhen 1Zaojia 8424Better growth performance.[43]
Cucurbita maxima × C. moschataQingyanzhen 1
Citrullus lanatus subsp. mucosospermusCrimson SweetImprove the ability to resist water stress, improve growth and yield.[38]
Cucurbita maxima × C. moschataStrong TosaCrimson Tide F1Enhance drought tolerance.[44]
Citrullus lanatus var. citroidesCrimson TideEnhance drought tolerance and affect physiological characteristics and nutrient uptake.[45]
Cucurbita maxima × C. moschataTZ-148
Citrullus lanatus var. citroidesA1, A2Crimson TideEnhance drought tolerance.[46]
Cucurbita maxima × C. moschataTZ-148Enhance drought resistance and improve fruit quality.
Temperature stressLagenaria sicerariaFR79SambokkulTolerance to low temperature, little effect on fruit quality.[20]
Lagenaria siceraria0526, 2505Zaojia 8424Enhance cold resistance.[47]
Cucurbita maxima × C. moschataQingyan No. 197103Enhance cold resistance.[48,49]
Cucurbita moschataWeizhen No. 1Nongkeda No. 5Enhance cold resistance.[50]
Cucurbita ficifolia BouchéCf
Salt stressLagenaria sicerariaChaofeng KangshengwangXiuliEnhance salt tolerance.[51,52,53,54]
Cucurbita maximaCmaCrimson TideEnhance salt tolerance.[55]
Lagenaria sicerariaSkp, Birecik
Citrullus lanatusJingxin No. 2Jingxin No. 2General salt tolerance.[56]
Cucurbita moschataQuanneng TiejiaGeneral salt tolerance.
Kaijia No. 1High salt tolerance.
Lagenaria sicerariaHanzhen No. 3High salt tolerance.
Citrullus lanatusZhongyu No. 9 tetraploidZhongyu No. 9Enhance salt tolerance.[57]
Lagenaria sicerariaC. lanatusEnhance salt tolerance.[58,59,60]
Cucurbita maxima × C. moschataShintosa F-90C. lanatusEnhance salt tolerance.[58]
Table 3. Effects of grafting on fruit quality of watermelon.
Table 3. Effects of grafting on fruit quality of watermelon.
RootstockScionChanges in Quality After GraftingReferences
Lagenaria sicerariaYongzhen No. 1,
Yongzhen No. 3,
Yongzhen No. 8		Zaojia 8424Increase SSC content.[80]
Cucurbita maxima × C. moschataYongzhen No. 7Zaojia 8424Increase fruit weight (SSC content did not change).[81]
Cucurbita maxima × C. moschataTZ148PegasusThe flesh firmness, color and other physical qualities were improved, and the contents of bioactive compounds such as lycopene and citrulline were increased, but the acidity was slightly increased.[82]
Cucurbita maxima × C. moschataSuper ShintosaMelodyIncrease the lycopene content.[83]
Cucurbita moschataMarvelIncrease fruit firmness.
Cucurbita maxima × C. moschataRoot Power
Lagenaria sicerariaMacisCrimson SweetIncreased the size and rind thickness of fruits.[84]
Cucurbita moschataSiZhuang8424Improve quality, increase beneficial metabolites, and reduce bitter compounds.[85]
Cucurbita moschataXi Jia Qiang ShengZhongyu No. 1Increase the total sugar, total amino acid and total acid content.[86]
Lagenaria sicerariaFR STRONGRX 467Reduce the lycopene content.[87]
Cucurbita maxima × C. moschataRS 841Increase the lycopene content.
Lagenaria sicerariaJingxinzhen No. 1ZaojiaIncrease the lycopene content.[88]
Citrullus lanatus var. citroidesYongshi
Cucurbita maxima × C. moschataQingyanzhen No. 1No effect on lycopene content.
Cucurbita maxima × C. moschataFerro, Nun 6001,
Shintoza		AswanIncrease the lycopene content.[19]
Cucurbita maxima × C. moschataTZ148PegasusIncrease fruit firmness and citrulline content.[89]
Cucurbita maxima × C. moschataJingxinzhen No. 297103Maturity extended.[90]
Cucurbita argyrosperma451Summer Flavor 800,
Summer Sweet 5244		Reduce fruit weight, lycopene content (diploid).[91]
Cucurbita maxima × C. moschataN101PegasusIncrease fruit firmness[92]
Cucurbita maxima × C. moschataTZ148, Bombo,
N101		Celebration, Gallery, Pegasus, TorpillaIncrease fruit firmness, lycopene content; SSC content decreased slightly.[93]
Cucurbita maxima × C. moschataFerro RZ, Nun 9075Crimson TideIncrease SSC content, peel thickness, fruit firmness.[94]
RS 841, Strong TosaIncrease lycopene content, peel thickness, fruit firmness.
Citrullus lanatus var. citroidesBGV0005167OneidaIncrease fruit thickness, flesh firmness, SSC content.[95]
Cucurbita maxima VAV 1860 × C. moschata PI 550689GMM1Increase fruit thickness and flesh firmness; change the fruit aroma.
Cobalt
Cucurbita maxima × C. moschataTZ-1481262Improve fruit taste.[96]
NuritImprove fruit taste, increase lycopene and SSC content.
Lagenaria sicerariaA3Crimson TideIncrease the sugar content of fruit.[46]
Lagenaria spp.Argentario, 3335187 × 125, 11 × 162Increase the SSC content, fruit diameter, peel thickness and fruit weight.[97]
Cucurbita maxima × C. moschataTZ148, Nun9075Increase fruit weight.
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Liu, X.; La, S.; Chen, C.; Shi, A.; Wang, M.; Zhang, Y.; Guo, J.; Dong, L. Research Progress on the Effect of Grafting Technology on Disease Resistance and Stress Resistance of Watermelon. Horticulturae 2025, 11, 1271. https://doi.org/10.3390/horticulturae11101271

AMA Style

Liu X, La S, Chen C, Shi A, Wang M, Zhang Y, Guo J, Dong L. Research Progress on the Effect of Grafting Technology on Disease Resistance and Stress Resistance of Watermelon. Horticulturae. 2025; 11(10):1271. https://doi.org/10.3390/horticulturae11101271

Chicago/Turabian Style

Liu, Xuena, Shikai La, Chang Chen, Ainong Shi, Mingjiao Wang, Yingying Zhang, Jinghua Guo, and Lingdi Dong. 2025. "Research Progress on the Effect of Grafting Technology on Disease Resistance and Stress Resistance of Watermelon" Horticulturae 11, no. 10: 1271. https://doi.org/10.3390/horticulturae11101271

APA Style

Liu, X., La, S., Chen, C., Shi, A., Wang, M., Zhang, Y., Guo, J., & Dong, L. (2025). Research Progress on the Effect of Grafting Technology on Disease Resistance and Stress Resistance of Watermelon. Horticulturae, 11(10), 1271. https://doi.org/10.3390/horticulturae11101271

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