Search Results (220)

In the last decade, avocado production has increased in Italy due to the fruit’s high nutritional quality and economic value. During 2024, stem lesions, wood discoloration and dieback, often starting at the grafting point, were observed in young plants in a nursery in Sicily (Italy). Colletotrichum-like colonies were frequently isolated from symptomatic tissues. Multi-locus phylogenetic analysis (gapdh, chs-1, act, tub2, cal, gs and ApMat) was conducted on 11 representative isolates, identifying 6 as C. perseae and 5 as C. gloeosporioides sensu stricto (s.s.). Two representative isolates were selected for pathogenicity tests performed on 2-year-old avocado plants cultivated in a greenhouse. After two months, necrotic lesions, wood discoloration and reddish-brown streaking at the inoculation point were induced in both species. Additional inoculations of avocado fruit confirmed the ability of both species to cause fruit rot. All inoculated fungi were successfully re-isolated and identified, fulfilling Koch’s postulates. This is the first report of stem lesions and dieback caused by Colletotrichum species and the first occurrence of C. perseae in avocado plants in Europe. The results highlight the importance of early monitoring in nurseries during the propagation process and contribute to a better understanding of fungal diseases in avocado crops in Italy. 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

Cold stress limits cucumber productivity, and grafting onto tolerant rootstocks offers a promising strategy for improving resilience. This study compared the responses of cucumber heterografts and self-grafts exposed to different cold temperatures, aiming to uncover the molecular basis of grafting-mediated tolerance. Morphological observations showed that grafting onto Cucurbita ficifolia and C. maxima X C. moschata cv. Tetsukabuto rootstocks improved plant growth under moderate cold, while extreme stress remained lethal. Transcriptome analysis revealed that heterografts displayed broader and more sustained differentially expressed genes than self-grafts. Gene ontology (GO) enrichment in heterografts indicated early activation of structural, regulatory, and metabolic processes, with continued enrichment at later stages. KEGG analysis highlighted plant hormone signaling as a central pathway modulated by heterografting, with selective regulation of auxin, ethylene, and ABA signaling. Heterografts activated key regulators, including MAPK3-like, TIFY5A, and CPK28, which were strongly expressed, alongside transcription factors from NAC, CAMTA, WRKY, and MYB families, suggesting coordinated regulation of cold-responsive networks. These results demonstrate that heterografting enhances cold tolerance by orchestrating multi-layered molecular responses, including hormone modulation, stress signaling, and transcriptional factors. This underscores the potential of grafting onto cold-tolerant rootstocks as a practical strategy for cucumber cultivation in cold-prone environments. Full article

Leaf area estimation using multispectral imaging in grafted cucumber seedlings is often underestimated due to leaf overlap at later growth stages. This study investigates the use of multispectral imaging technology to estimate leaf area in grafted cucumber seedlings and proposes a method to improve estimation accuracy by introducing “days after grafting” (DAG) as a correction variable. For the experiments, the scion varieties ‘Goodmorning Backdadagi’, ‘NakwonSeongCheongJang’, and ‘Sinsedae’ were grafted onto the same rootstock ‘Heukjong’ (Cucurbita ficifolia), and images were acquired at 7, 14, and 21 days after grafting. The results show that including DAG as a correction variable significantly enhances the accuracy of image-based leaf area estimation, particularly in plug tray units, where R² increased from 0.89 to 0.96 for ‘Goodmorning Backdadagi’, by effectively reducing errors caused by leaf overlap. Across all three varieties and both seasons (spring and summer), models incorporating DAG consistently showed higher accuracy in leaf area estimation than models without DAG. These results suggest that the method’s broad applicability is validated through comparisons across different seasons and varieties. Overall, this study provides a practical and accurate method for correcting leaf area estimation, with strong potential for application, particularly in seedling production and cultivation management. Full article

This paper presents a valve-controlled pipeline humidification system aimed at achieving precise and uniform humidity regulation in the multi-layer cultivation environments of plant factories. Since grafted seedlings require stable humidity conditions for effective healing, the system was designed to enable fine-grained adjustments across different cultivation layers. A quadratic regression orthogonal rotational combination design was employed to investigate how valve opening angles affect mean relative humidity (MRH), and a regression prediction model was developed accordingly. The model exhibited strong predictive performance, achieving an R² of 0.9907 and an average relative error of only 0.67%. The optimal valve-opening angles were 60°, 50°, and 50°, respectively, which ensured that the MRH remained above 90% throughout operation. Experimental verification confirmed that the model accurately predicted humidity responses, while the proposed system improved uniformity by reducing the humidity variation from 6.1% to 0.3% and increasing the compliance rate from 58.3% to 100%. To enhance short-term humidity forecasting, three machine learning algorithms—Random Forest, XGBoost, and Transformer—were trained to predict humidity trends within a 6-h window. Among them, the RF model achieved the highest accuracy with an R² of 0.9543, outperforming the other models in both stability and precision. The main contribution of this study is the identification of the optimal valve-opening combination through a quadratic orthogonal rotation regression combination experiment. Additionally, the RF obtained the optimal machine learning model for predicting humidity within 6 h. 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

Background: Articular cartilage has limited self-repair capacity. While thermoresponsive poly N-isopropyl acrylamide (pNIPAAm)-based Cell Sheet Engineering (CSE) is a promising scaffold-free strategy, its inherent material properties pose limitations. This study developed and validated a novel, non-thermoresponsive CSE platform for functional cartilage regeneration. Methods: A culture platform was fabricated by grafting the biocompatible polymer poly gamma-glutamic acid (γ-PGA) and a disulfide-containing amino acid onto porous PET membranes. This design enables intact cell sheet detachment with its native extracellular matrix (ECM) via specific cleavage of the disulfide bonds by a mild reducing agent. Results: The hydrated substrate exhibited a biomimetic stiffness (~16.2 MPa) that closely mimics native cartilage. The platform showed superior biocompatibility and supported the cultivation of multi-layered rabbit chondrocyte sheets rich in Collagen II and Glycosaminoglycans. Critically, in a rabbit full-thickness defect model, transplanted autologous cell sheets successfully regenerated integrated, hyaline-like cartilage at 12 weeks, as confirmed by MRI, CT, and histological analyses. Conclusions: This novel CSE platform, featuring highly biomimetic stiffness and a gentle, chemically specific detachment mechanism, represents a highly promising clinical strategy for repairing articular cartilage defects. Full article

Background: The integration of 3D bioprinting, biomaterials science, and cellular biology presents a viable strategy for maxillofacial bone regeneration, overcoming the constraints of traditional graft techniques. This review offers a thorough examination of the present condition, obstacles, uses, and future outlook of 3D bioprinting technology in maxillofacial bone regeneration. An essential understanding has been attained by analyzing the technological constraints, specifically in vascularization and neuro-integration, and by delineating the vital translational pathway from benchtop models to clinical application. We have examined several bioprinting techniques—namely extrusion, inkjet, and laser-assisted methods—and the requisite bioinks, emphasizing their physicochemical and biological features vital for osteogenesis. Significant clinical applications, including the treatment of trauma-induced abnormalities and the reconstruction of oncology-related resections, have been emphasized. This review highlights the urgent necessity for established regulatory frameworks and refined printing settings to guarantee effective, functional, and durable bone substitutes, providing a distinct pathway for future research and clinical implementation in this specialized surgical domain. Aim: The purpose of this review was to present a general overview of the current clinical and diagnostic applications of bioprinting in bone tissue engineering for the reconstruction of bone defects. Methods: A search of major scientific databases, including PubMed, Science Direct, Embase, and Cochrane, was conducted. Articles published within the last 10 years that analyze the possible applications of bioprinting in bone tissue fabrication were included. Results: Several bioinks, based on hydrogels and stem cells, can enable the fabrication of such tissues using this technology. This review reports on the processes adopted for the bioprinting of bone tissue, the bioinks used, and cell cultivation methods. Conclusions: Bioprinting represents a promising solution for bone regeneration with potential applications that could revolutionize current surgical practices, despite the many challenges that future research will face. Full article

Cultivation practices such as fruit thinning and soil management with ground covers are commonly applied in Citrus orchards, yet their physiological impact on young trees remains poorly documented. This study evaluated the effects of manual fruit thinning and weed-control mesh on vegetative growth, fruit development, and leaf mineral composition of Citrus sinensis L. Osbeck cv. ‘Navelina’ grafted on Citrus macrophylla. A six-month field experiment was conducted in southeastern Spain under semi-arid Mediterranean conditions using six treatments that combined different soil coverage and subsurface drainage systems. After physiological fruit drop, trees were standardized to ten fruits per plant. Vegetative parameters (canopy and trunk dimensions), fruit growth (size, juice content), and foliar nutrient concentrations were monitored. Trees with ground cover showed significantly greater canopy expansion and juice yield compared to uncovered controls. A negative correlation between fruit number and canopy-to-fruit volume ratio highlighted the trade-off between vegetative vigor and fruit load. Foliar analysis revealed lower micronutrient concentrations (Fe, Mn, B, Zn) in uncovered trees, suggesting reduced nutritional status. These findings demonstrate that combining early thinning with weed-control mesh promotes vegetative vigor, improves juice yield, and enhances nutrient uptake, providing practical insights for optimizing orchard establishment and early Citrus productivity in water-limited environments. Full article

Apple production in the arid and semi-arid regions of Northwest China, such as Lingwu in Ningxia, faces severe challenges due to water scarcity, which is exacerbated by climate change. To address this issue, this study aimed to identify superior drought-tolerant apple varieties grafted onto the dwarfing interstock SH40 for cultivation in the Lingwu region. Seven major commercial varieties (‘Yanfu 3’, ‘Yanfu 6’, ‘Yanfu 8’, ‘Huashuo’, ‘Golden Delicious’, ‘Starking Delicious’, and ‘Red General’) were evaluated. Under natural drought stress conditions in Lingwu, we measured physiological and biochemical indices, photosynthetic parameters, leaf anatomical structure, and post-harvest fruit quality and yield. Principal component analysis (PCA) and membership function analysis were then employed for a comprehensive evaluation of drought resistance. The results revealed significant varietal differences. ‘Red General’ exhibited superior antioxidant enzyme activities (peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) and higher photosynthetic rates (net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr). ‘Golden Delicious’ showed the highest malondialdehyde (MDA) content but also possessed advantageous leaf anatomical traits, such as a high palisade-to-spongy tissue ratio. PCA extracted five principal components with a cumulative variance contribution rate of 95.492%. Membership function analysis ranked overall drought resistance as follows: ‘Red General’ > ‘Golden Delicious’ > ‘Starking Delicious’> ‘Huashuo’ > ‘Yanfu 6’ > ‘Yanfu 8’ > ‘Yanfu 3’. In conclusion, the mid-season varieties ‘Red General’, ‘Golden Delicious’, and ‘Starking Delicious’ demonstrated excellent comprehensive drought tolerance and are recommended as promising candidates for cultivation in the arid Lingwu region. Full article

Sweet cherry (Prunus avium L.) cultivation is rapidly expanding in Northern Italy, where excessive vegetative vigor often limits fruit set and quality. This study aimed to evaluate the effects of Prohexadione-calcium (Pro-Ca) on the vegetative growth, productivity, and fruit quality of cv. ‘Tip Top’ sweet cherries grafted onto Gisela 6 and MaxMa 14 rootstocks. The growth regulator was applied twice between the flower bud and petal fall stages. Pro-Ca significantly reduced vigor and increased the fruit setting by 10%, resulting in an yield average of +3 kg per plant. Also preharvest treatment increased average cherry size compared with the control, particularly in plants grafted onto Gisela 6. Moreover, Pro-Ca-treated fruits exhibited a +20% red overcolor extension of the skin, improved skin firmness (+12%), and led to higher nutraceutical properties. In conclusion, Pro-Ca improved plant yield and fruit quality in ‘Tip Top’ sweet cherry, likely through the combined effects on hormonal balance, assimilate allocation, and canopy light distribution, supporting its potential as a valuable growth regulator in high-density sweet cherry orchards. Full article

A field study was conducted on the plants of two grapevine cultivars, ‘Solaris’ and ‘Regent’, grafted onto an SO 4 rootstock (V. berlandieri × V. riparia) and characterized by strong growth and yield. The effect of twelve treatments on the concentration of macroelements in leaf blades in the véraison phase, as well as selected soil parameters, was assessed in the sixth, seventh and eighth year of their application. The following treatments were tested: control (no fertilization), NPK (mineral fertilization 70 kg N/ha; 40 kg P/ha; 120 kg K/ha), mycorrhizal substrate (AMF—arbuscular mycorrhizal fungi), NPK + AMF, manure before planting, NPK + manure before planting, BioIlsa, NPK + BioIlsa, BF-Ecomix, NPK + BF-Ecomix, Ausma, NPK + Ausma. The aim of the study was to assess the nutritional status of the two cultivars after long-term use of mineral fertilizers, organic fertilizers, biofertilizers and biostimulants under Polish conditions in soil with a low organic matter (SOM) content prone to acidification. AMF, organic fertilizers and biostimulants were not a sufficient alternative to mineral fertilizers, especially with regard to N supply. BF-Ecomix treatment increased the content of Mg in the soil and the soil pH value. Regular use of NPK fertilization increased the concentration of leaf N and K, but did not improve the nutritional status of plants with P, despite doubling its content in the soil compared to control. NPK fertilizers worsened the availability and accumulation of Mg and caused soil acidification, but resulted in a slight increase in total soil N and SOM. No significant differences were noted in the mineral status of both cultivars under the same fertilization treatments but liming improved the leaf Ca status in ‘Solaris’. Fertilization of grapevines, which have started to be cultivated in Poland due to the warming climate, requires further study. Mineral fertilization should not be routine, but rather constantly readjusted, taking into account the soil fertility and mineral status of plants, in order to use the nutrients more effectively and avoid their unfavorable effects on plants and soil. Full article

Non-bagging apple cultivation, which is time-saving, labor-saving, and cost-effective, represents the future direction of apple cultivation in China. However, compared with bagging cultivation, it degrades fruit appearance quality, characterized by rough peels and dull colors, with the underlying physiological and molecular mechanisms remaining unclear. This study used ‘Tianhong 2’ Fuji apples, grafted onto SH dwarfing rootstock, and integrated transcriptomics–metabolomics to explore these mechanisms. Results showed that non-bagging-cultivated apple peels had higher chlorophyll and carotenoid contents but lower anthocyanin content than those of bagging-cultivated ones. Transcriptome sequencing identified 1571 differentially expressed genes (DEGs: 1269 upregulated, 302 downregulated). Functional analysis revealed that the decline in fruit appearance quality was primarily associated with secondary metabolite biosynthesis, lipid metabolism, and carbohydrate metabolism, and 34 candidate genes were identified. Metabolomic analysis detected 394 differentially expressed metabolites (DEMs), 38 of which were closely related to the non-bagging-induced appearance degradation, mainly lipids, organic oxygen compounds, and organic acids and their derivatives. Integrated analysis of DEGs and DEMs indicated the involvement of multiple critical metabolic pathways, including cutin, suberin and wax biosynthesis; starch and sucrose metabolism; cyanoamino acid metabolism; and phenylpropanoid and flavonoid biosynthesis. Compared with bagging-cultivated apples, non-bagging-cultivated apples exhibited faster starch degradation and higher soluble sugar accumulation. Additionally, the accumulation of specific metabolites [e.g., quercetin (HMDB0005794, HMDB03249, LMPK12112097), and suberin components (LMFA01170020, LMFA01050437, HMDB0031885)], along with elevated organic acid levels, contributed to peel roughness and dull coloration. These findings further enrich the theoretical basis for the formation of fruit quality in Fuji apples under non-bagging cultivation and provide valuable theoretical guidance for the practical application of this cultivation mode. Full article

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. Full article

‘Hainan Qingyou’ (Citrus maxima) Pomelo is one of the predominant local cultivars cultivated in Hainan Province, renowned for its high economic value and strong market competitiveness. However, during cultivation, it was observed that the fruit quality of ‘Hainan Qingyou’ grafted onto a ‘Sanhong’ interstock deteriorated, predominantly manifesting as vesicle granulation. This study was therefore conducted to investigate this phenomenon using ‘Sanhong’ Honey Pomelo as the interstock. Fruit quality indicators were measured, and pulp transcriptomic analysis was performed during the expansion and maturation stages. The results indicated that fruits grafted onto ‘Sanhong’ interstock (SHZ) exhibited increased peel thickness, yellower peel, reduced edible rate, higher pulp firmness, decreased total soluble solids (TSS), increased total acid content, and reduced total antioxidant capacity at maturity, all contributing to diminished fruit quality. Additionally, SHZ fruit accumulated higher lignin content in the pulp, leading to vesicle granulation, which severely compromised marketability. Transcriptomic analysis identified 42 structural genes involved in lignin biosynthesis in ‘Hainan Qingyou’ pulp, including 5 PAL, 2 C4H, 2 4CL, 6 CAD, 15 PER, 2 HCT, 1 C3′H, 1 CCoAOMT, 1 CCR, 1 COMT, 2 CSE, and 1 F5H genes. Most of these genes were highly expressed in SHZ fruit at maturity, with expression levels significantly higher than those in fruit grafted onto ‘Hainan Qingyou’ interstock (QYZ). The interstock also affected hormone signaling pathways. Weighted gene co-expression network analysis (WGCNA) identified transcription factors such as MYB, MIKC, ERF, and bZIP as key regulators involved in pulp lignin biosynthesis. This study provides insights into the effects of rootstocks on citrus fruit quality and offers valuable information for cultivar improvement in pomelo orchards. Full article