Search Results (252)

The importance of magnesium (Mg) is often overlooked in modern crop production. Tomato (Solanum lycopersicum L.) is commonly grafted onto appropriate rootstock to improve the nutrient uptake, which may have a negative effect on the tomato Mg leaf concentration and possibly influence the carbohydrate partitioning required for optimal crop yield and quality. The aim of this study was to screen tomato cultivars and rootstocks under Mg deficiency using two experiments. The first experiment included a panel of 14 tomato cultivars and 10 rootstocks grown with 1 or 0.1 mM Mg in nutrient solution. The second experiment consisted of four cultivars either self-grafted or grafted onto four rootstocks chosen from the first experiment. In both experiments, most of the plants grown under low-Mg conditions, on average, had a higher biomass production. The magnesium concentrations in the leaves and stems (but not in the roots) of both cultivars and rootstocks, non-grafted or grafted, were significantly higher under optimal Mg supply. Regarding the Mg content, the differences between the Mg supplies were up to three-fold for cultivars, up to two-fold for the rootstocks, and up to five-fold for the combinations of grafted plants. Our results showed that genotypic differences between used tomato cultivars and rootstocks in response to Mg can be observed at early developmental stages and can possibly serve as a tool in screening programs, but further research is needed to assess their relationship with long-term cultivation. Full article

Rootstocks play a central role in modulating grapevine responses to water scarcity, yet their morpho-functional strategies remain highly genotype-dependent. This study compared three functionally contrasting rootstocks, 1103 Paulsen, 420 A, and M2, grafted with Vitis vinifera cv. Merlot, which differ in root system architecture, hydraulic efficiency, canopy development, and stomatal regulation, with the aim of elucidating their hydraulic, morphological, and physiological responses under controlled conditions. Plants were grown in containers and assessed for root system architecture, hydraulic conductance, gas exchange including transpiration rate, chlorophyll fluorescence, and biomass allocation. The results revealed three distinct adaptive strategies: 1103 P exhibited the highest structural root biomass and rootstock hydraulic conductivity, supporting elevated axial water transport, higher transpiration rates, and a larger canopy, consistent with an “active tolerance” strategy; 420 A showed balanced structural and absorptive root development, moderate hydraulic performance, and the highest transpiration rates, reflecting a flexible, opportunistic response to water availability. In contrast, M2 displayed markedly reduced structural root biomass but a high proportion of absorptive roots and the greatest scion hydraulic conductance combined with low stomatal conductance, reduced transpiration, and high intrinsic water use efficiency, which is indicative of a conservative, resource-efficient strategy. These findings demonstrate that the three rootstocks express fundamentally different drought response syndromes driven by coordinated variation in root morphology, hydraulic traits, canopy development, and stomatal behavior. The integration of hydraulic and morphological traits provides a robust framework for selecting rootstocks tailored to specific pedoclimatic and management contexts in water-limited environments. Full article

Drought stress represents a major constraint on global apple production, with the widely used semi-dwarfing rootstock ‘M.26’ being particularly vulnerable to water deficit. Although the osmolyte trimethylamine N-oxide (TMAO) has been shown to improve abiotic stress tolerance in the model plant Arabidopsis, its potential role in enhancing drought resilience in woody fruit trees remains largely unexplored. Under prolonged moderate drought stress, exogenous TMAO application significantly promoted plant growth, mitigating the drought-induced suppression of plant height by 5.3–12.2% compared to untreated drought-stressed controls and alleviating the decline in above-ground biomass. This improvement was underpinned by a substantial alleviation of root growth inhibition, with TMAO restoring total root length and biomass from 37% in the control to only 6.1–9.5%. TMAO also fine-tuned the root-to-shoot ratio to favor resource allocation to roots. Consequently, TMAO-treated plants maintained superior leaf water status, exhibiting higher relative water content (drought-induced reduction limited to ~17.5% with TMAO versus 26.3% in the control). Physiologically, TMAO alleviated the drought-induced stomatal limitation of photosynthesis, sustaining higher net photosynthetic rate, stomatal conductance, and transpiration rate. Crucially, under severe drought stress, TMAO pretreatment markedly enhanced ‘M.26’ survival rates from approximately 39% in the untreated control to 60–68%, representing a relative increase of approximately 74%. Collectively, this study demonstrates that exogenous application TMAO significantly enhances drought tolerance in apple rootstock ‘M.26’, highlighting its potential as an effective and environmentally safe plant growth regulator for more sustainable cultivation of fruit trees under irregular/erratic irrigation conditions. Full article

Pumpkin seedlings serve as rootstocks for watermelon grafting, and the partial leaf trimming operation performed approximately two days before grafting is crucial for the survival rate of grafted watermelon seedlings. Extracting the position of the main veins of the leaf is a prerequisite for achieving automated partial pruning. The existing methods have problems such as low segmentation accuracy and misclassification between primary and branch veins in the pumpkin seedling segmentation task. This study proposes a three-classification segmentation model Dynamic Region Enhancement Transformer (DRE-Former) of main vein, branch vein and background, as well as a post-processing system. The encoder of DRE-Former consists of two modules. The former is Dynamic Frequency Conv and Normalized Efficient Conv (DN Block), which can enhance the feature extraction ability for small targets. The latter is the Region Transformer Block, which enhances the ability to distinguish between the main vein and the branch vein. In addition, in the skip connection part of the model, a Skip Connection Fusion Block (SCF Block) has been added, which can reduce the dilution degree of detailed features. The post-processing section outputs the cutting position and cutting Angle through rule-based methods and geometric analysis. The experimental results show that the proposed model achieves mean Intersection-over-Union (mIoU) and Overall Accuracy (OA) of 90.80% and 95.88%, respectively, outperforming the comparative models. In stability and error testing, the average standard deviation is 0.60, and the average relative error is 11.90%. Compared with the primary mIoU data in the dataset, the average relative error differs by only 2.11%. The post-processing system enables the accurate determination of cutting positions and angles, but it has a strong dependence on the segmentation model. The research can provide reliable technical support for the subsequent automatic cutting equipment for pumpkin seedlings. Full article

The quality and yield of grafted tomato seedlings are significantly influenced by the selection of high-quality and robust rootstocks. The effectiveness of these rootstocks is dependent on various environmental factors and genetic traits. One of the most critical factors in cultivation is light, as its intensity plays a vital role in seedling growth, overall development, metabolic processes, the efficiency of the photosynthetic system, and other essential plant functions. The aim of this study was to investigate the changes in the photosynthetic system activity and the growth of tomato rootstocks depending on the light intensity. The study was conducted at the Institute of Horticulture, Lithuanian Center for Agricultural and Forestry Sciences, focusing on four tomato rootstock varieties grown in a controlled environment. The plants were grown at a temperature of +23/19 °C and a relative humidity of 55–60%, under different levels of illumination (high-pressure sodium lamps), PPFD: 150, 250 and 350 ± 10 µmol m⁻² s⁻¹. The results indicated that optimal growth and biomass accumulation occurred at around 250 µmol m⁻² s⁻¹, with the most significant growth observed in the rootstocks ‘Auroch’ and ‘Goldrake’. Higher light intensities, specifically at 350 µmol m⁻² s⁻¹, did not consistently enhance growth and could even lead to a reduction in leaf area and overall growth in some cultivars such as ‘Auroch’ and ‘TOR23901’. Although photosynthetic parameters improved with increased light intensity up to 350 µmol m⁻² s⁻¹, these enhancements did not translate into additional growth benefits. Full article

The response of cocoa (Theobroma cacao L.) to low oxygen availability in the soil and the possibility of recovery after stress relief are associated with the plasticity capacity of each genotype; however, studies evaluating the influence of rootstock on stress response are scarce. Thus, in the northern region of the state of Espírito Santo, municipality of São Mateus, the physiological, biochemical, and anatomical responses and recovery capacity of cocoa PS-1319 grafted onto the rootstocks TSH-1188, Cepec-2002, Pará, Esfip-02, and SJ-02 were evaluated under flooded conditions. The plants were subjected to flooding for 60 days, and their recovery capacity was assessed after this period. The gas exchange, relative chlorophyll content, stem and leaf anatomy, photosynthetic pigments, and carbohydrates were evaluated. All genotypes showed reductions in net photosynthetic assimilation, stomatal conductance, and transpiration rate in the flooded environment compared to the non-flooded environment. All pigments were degraded, with average values of Chl a, Chl b, total Chl, and total carotenoids of 9.33, 10.418, 19.75, and 590.75 μg.mL⁻¹ in the non-flooded environment and 6.43, 7.69, 14.12, and 500.33 μg.mL⁻¹ in the flooded environment. The rootstocks Cepec-2002 and Esfip-02 showed the highest carotenoid accumulation, with 585.78 and 650.47 μg.mL⁻¹, respectively, when compared to SJ-02 (474.03 μg.mL⁻¹), Pará (491.58 μg.mL⁻¹), and TSH-1188 (525.86 491.58 μg.mL⁻¹). The Pará rootstock did not show differences in stomatal density between environments, with values of 32.25 in flooding, 34.83 in non-flooding, and 31.61 in recovery. During flooding, lenticels formed in all rootstocks. After recovery, all rootstocks normalized their gas exchange, carbohydrate levels, and anatomy, showing that the root system was able to re-establish its functions, making these rootstocks suitable for areas at risk of flooding. Full article

As a coastal brush, Atalantia buxifolia is a good rootstock of citrus plants around sea shores, but its salt tolerance has not been studied. In order to explore the salt tolerance of A. buxifolia, its seeds and seedlings were subjected to NaCl stress treatment, followed by phenotypic observation and biochemical and transcriptome analysis. Results showed that the increase in NaCl concentrations resulted in the decrease in germination rates, germination potential, germination index, and vigor index of A. buxifolia seeds, as well as growth of epicotyl and radicle, and biomass of A. buxifolia seedlings. However, the seeds of A. buxifolia could adapt to the growth of 100 mM NaCl concentration to a certain extent. The levels of malondialdehyde (MDA) and relative electrolyte leakage increased with the increase in NaCl concentrations. However, under treatment of 100 mM NaCl, the biomass, POD, CAT, APX, GSH, AsA, H₂O₂, MDA, and relative electrolyte leakage of A. buxifolia seedlings did not show significant changes compared with the control treatment. Transcriptome analysis showed that expression of differential genes increased with the increase in NaCl concentrations. GO enrichment showed that the most annotated genes were metabolic process, cell and cell composition, and binding. The KEGG pathway annotation shows that differential genes were mainly enriched in some pathways, such as photosynthesis antenna proteins, plant hormone signal transduction, glutathione metabolism, and starch and sucrose metabolism. In addition, differentially expressed genes had been annotated into 45 transcription factor families, including the largest number of bHLH, NAC, WRKY, MYB, and bZIP families. The results provide a basis for further understanding the salt tolerance mechanism and exploring related salt tolerance genes of A. buxifolia. Full article

Valsa canker, a destructive necrotrophic disease caused by Valsa species (V. mali and V. pyri), threatens global apple and pear production. Resistance breeding has gained much attention because of its environmental friendliness and effectiveness, making it extremely critical to obtain key disease resistance genes. In this study, we identified that the expression of PbeSTOP2, a C2H2-type transcription factor in ‘Duli-G03’ (Pyrus betulifolia, rootstock of pear), was induced in response to signals from Vp and Vp metabolites (VpM). Transient expression in fruits and stable overexpression in suspension cells demonstrated that PbeSTOP2 enhances resistance to Vp. In overexpressing cells, genes associated with jasmonic acid (JA) and pattern-triggered immunity (PTI) signaling were upregulated, and endogenous JA and auxin (IAA) levels increased. These results revealed that JA signaling was involved in the enhanced Valsa canker resistance conferred by PbeSTOP2 overexpression. This finding on host disease resistance should facilitate the breeding efforts for Valsa canker resistance. Full article

Grafting is a strategy to mitigate biotic and abiotic stresses in coffee systems. However, initial compatibility indicators between Coffea arabica scions and C. canephora rootstocks under controlled conditions remain insufficiently documented. We evaluated the physiological and morphological compatibility of four C. arabica cultivars (Bourbon, Geisha, Catuai, and Villa Sarchí) grafted onto C. canephora (Robusta) rootstock in a tropical highland nursery in the Peruvian Amazon. Seven physiological and six morphological variables were measured. Statistical analyses included one-way ANOVA and Kruskal–Wallis tests with Bonferroni post hoc comparisons. Two physiological parameters were significantly higher in Villa Sarchí grafts than in Robusta: PSII quantum yield (+0.044 units; p < 0.05) and electron transport rate (+14.702 µmol e⁻ m⁻² s⁻¹; p < 0.05); by contrast, net photosynthesis, stomatal conductance, intercellular CO₂ concentration, and transpiration did not differ, and maximum PSII efficiency was similar among treatments (p = 0.509). Conversely, no morphological trait showed significant differences, and graft-take was high across all combinations. The results support the use of Coffea robusta as a rootstock for these four cultivated varieties, thereby offering the possibility of improving their resilience in tropical highland regions. Full article

Mango (Mangifera indica L.) is a tropical fruit tree characterized by vigorous growth and high fruit production, making it one of Peru’s main export crops. However, its extensive vegetative development requires substantial space, limiting productivity per unit area. This study evaluated the effects of rootstock and interstock combinations on agronomic traits and fruit biometrics, highlighting the potential of interstocks to modulate tree vigor in mango orchards of Peru’s dry forest region. A total of 216 trees were established using ‘Chulucanas’ and ‘Chato’ as rootstocks and ‘Chulucanas,’ ‘Chato,’ ‘Irwin,’ and ‘Julie’ as interstocks, apically grafted with the ‘Kent’ cultivar, with a spacing of 6.0 m × 6.0 m. Tree performance was assessed after 10 years during the 2017–2019 growing seasons in Piura, Peru, under a randomized complete block design (2 × 4 factorial). The combination of the ‘Chulucanas’ rootstock with ‘Chulucanas’ and ‘Julie’ interstocks reduced tree height by 10.94% and 11.70%, respectively, facilitating orchard management and potentially increasing planting density. Yield varied significantly among growing seasons, with a 15% reduction in 2017 attributed to El Niño–Southern Oscillation (ENSO)-related increases in temperature and rainfall that affected flowering and fruit set. These results underscore the importance of cultivar selection and climate-adaptive strategies to sustain mango productivity in regions prone to climatic variability. Full article

Soil salinity and bicarbonate-induced alkalinity severely limit melon productivity by disrupting physiological and biochemical processes. This study evaluated the effectiveness of grafting an Iranian cantaloupe cultivar, ‘Til-e-Sabz’, onto Cucurbita maxima × C. moschata rootstock in mitigating salinity (10 mM NaCl; 2.7 dS m⁻¹) and alkalinity (10 mM NaHCO₃; 2.6 dS m⁻¹) stress in soilless culture. Compared to non-grafted plants, grafted plants exhibited 22–35% greater leaf area, 28–40% higher shoot and root fresh biomass, and 25–38% higher dry biomass under both stress conditions. Relative chlorophyll content (SPAD) and total chlorophyll were reduced by stress but remained 15–21% higher in grafted plants. Carotenoid content was also maintained at 10–14% higher levels in grafted plants compared to non-grafted controls. Proline and soluble protein accumulation increased significantly under stress, with grafted plants accumulating 18–25% more proline and 12–20% more protein, indicating enhanced osmotic adjustment. Sodium levels increased in the roots and shoots under stress. However, grafted plants maintained 30–45% lower Na accumulation relative to non-grafted plants. In contrast, grafted plants showed up to 27% higher phosphorus and 32% higher iron uptake, while maintaining greater potassium retention (18–24%) under both salinity and alkalinity. Overall, grafting significantly improved physiological resilience and ion homeostasis, leading to enhanced stress tolerance. These findings demonstrate that grafting is a promising agronomic strategy to sustain melon production in saline and alkaline environments associated with increasing soil and water degradation. Full article

Pumpkin is widely used as a rootstock to enhance salt tolerance and improve productivity of Cucurbit crops. To date, the morphology and ion parameters of pumpkins at a certain time point under salt stress are well-known. However, the dynamic changes in organ morphology and K⁺/Na⁺ content of pumpkin under salt stress and the relationship of them remain unclear. Therefore, this study investigated biomass, root morphology, stem structure, and K⁺/Na⁺ content in salt-sensitive (JZ-1) and salt-tolerant (JYZ-1) pumpkins under 0 mM and 120 mM NaCl conditions at 2, 5, and 10 days after treatment (DAT). Our results show that at the beginning, NaCl treatment led to a sharp decrease in shoot fresh weight by 30–53% and a slight decrease in root fresh weight, plant dry weight, and total root length and affects the K⁺ and Na⁺ content both in JZ-1 and JYZ-1 at 2 DAT. Subsequently, total root volume and number of tips have changed, in which NaCl treatment resulted in a significant increase of 127% in total root volume and a significant decrease of 38.4% in number of tips in JYZ-1 at 5 DAT, but no significant difference in JZ-1 at 5 DAT was found. At the end, root fresh weight and stem structure parameters were significantly decreased by NaCl treatment at 10 DAT both in JZ-1 and JYZ-1, and stem cross-sectional area under NaCl conditions in JZ-1 and JYZ-1 at 10 DAT (2.133 and 2.316 mm³, respectively) was significantly lower than that under control conditions (2.933 and 4.441 mm³, respectively). Additionally, shoot K⁺ content showed a trend of first upward and then downward in JZ-1 and a slightly decreasing trend in JYZ-1, and shoot Na⁺ content displayed a trend of first downward and then upward in JZ-1 and a slightly increasing trend in JYZ-1. It is suggested that shoot K⁺ content, shoot Na⁺ content, and total root volume be considered as the important parameters for pumpkin salt tolerance assessment. These findings will help us better understand the mechanisms of salt tolerance and improve the efficiency of identification of salt-tolerant pumpkin. Full article

Nitrogen (N) deficiency in apples (Malus × domestica Borkh.) leads to characteristic physiological symptoms, including leaf and fruit discoloration. Fertigation, i.e., the application of dissolved fertilizers, can significantly improve the growth and fruit quality of apples while optimizing nutrient uptake through a more precise and better timed application than conventional fertilization. This study therefore investigates how different fertilization treatments affect the N concentration of different age categories of apple leaves. Apples of the variety ‘Braeburn’ were grown hydroponically on the low-vigorous rootstock M9. Four fertilizer treatments were used: (1) Hoagland solution (HS); (2) HS nitrogen excluded; (3) HS iron excluded; and (4) HS magnesium excluded. Through vegetation, leaf samples were taken from three shoot positions representing different leaf ages (young, semi-young and old) and then chemically analyzed. The lowest N concentrations across all leaf ages and sampling moments were found in the treatment with N excluded (1.69–2.07% N), while the highest values occurred in the treatments where iron (2.00–2.49% N) or magnesium (1.98–2.37% N) were excluded. The seasonal changes in N concentration reflect interactions between the leaf age and the sampling moment. These results show that the N concentration of apple leaves strongly depends on the type of fertilization. Full article

Selecting an appropriate rootstock for a specific scion cultivar is an efficient way to improve both yield and berry quality in viticulture. This study aimed to provide practical guidance for rootstock selection in the cultivation of the table grape cultivar ‘Fengguang’. The mature scions of this cultivar were grafted onto hardwood cuttings of eight different resistant rootstocks, which included 101-14M, 110R, 188-08, 3309C, 5BB, 5C, SO4, and Beta, with the own-rooted vines as control. Graft compatibility, growth vigor, yield performance, and fruit quality were compared and analyzed among the different grafting combinations. The results suggested that vines on 101-14M, 5BB, and Beta obtained higher germination rates of scions, better healing rates of the mating interface, and greater generation rates of root callus. Among these, vines on 5BB exhibited the largest scion trunk cross-sectional diameter. Furthermore, SO4 demonstrated the most significant improvement in yield, with an average increase of 13.54% compared to the control. Regarding berry quality, 101-14M significantly enhanced berry mass, pressure resistance, and flesh firmness relative to the controls, with average improvements of 7.67%, 11.34%, and 29.86%, respectively. Based on a comprehensive evaluation of yield and fruit quality indicators, 101-14M gained the highest value. In conclusion, 101-14M is preferentially recommended for grafting cultivation of ‘Fengguang’ vines. These findings could provide practical guidance for the cultivation of table grape cultivars. Full article

Rootstock choice offers a powerful lever for tailoring economically important trees to adverse environments. Camellia oleifera Abel., a premier oil-producing species cultivated widely on red-soil hills, suffers large yield losses under chronic phosphorus deficiency. We grafted a single elite scion (CL4) onto three contrasting rootstocks (CL4, CL3, CL53) and monitored growth and root transcriptomes for 1.5 years under adequate (1 mM) or limiting (0 mM) P supply. Under low-P stress, the rootstock identity reshaped the root architecture: CL4/CL3 produced the longest, most extensive network, increasing the total root length by 49.7%, the surface area by 52.9%, and the volume by 42.6% relative to the control, whereas leaf morphology responded solely to P supply, not to the graft combination. CL4/CL3 also accumulated up to more than 17.5% of root biomass and 28.25% of whole-plant biomass than any other combination. Physiologically, CL4/CL3 acted as an aggressive P miner, accumulating 67.8% more P in its roots than the self-grafted control under P limitation, while CL4/CL4 maximized the internal P use efficiency, showing a 44.74% higher root P use efficiency than CL4/CL53—two contrasting yet effective strategies for coping with low-P stress. Transcriptome profiling uncovered 1733 DEGs in the CL4/CL3 and 2585 in the CL4/CL4 roots, with 150 and 255 uniquely co-expressed genes, respectively. CL4/CL3 up-regulated organic-acid and phenylpropanoid pathways; CL4/CL4 activated defense and phosphate transport networks. qRT-PCR of six genes confirmed that CL4/CL3 mounted a stronger low-P response via MAPK, hormonal, and lipid–metabolic signaling. These results provide a mechanistic framework for rootstock-mediated P efficiency and establish a foundation for the molecular breeding of C. oleifera under nutrient-limited conditions. Full article