Search Results (183)

The paper outlines soil–tool interaction investigations according to parameters of the trencher disc cutter with a variable installation angle relative to the rotation axis that ensure the required trench shape and dimensions. The research results make it possible to improve the quality of the technological process for obtaining the needed trench shape. The movement of soil particles on the knife surface and after their removal was considered using the principles of soil mechanics, mathematical analysis, and computer (3D) modelling taking into account centrifugal force, gravity and friction. Research has shown that the soil particles’ movement is spatially complex and can be described by parabolic dependencies when projected onto coordinate planes. It is proved that changing the angle of installation of the disc in the range of 90–80° allows the furrows’ width to be adjusted within the range of 0.1–0.5 m while maintaining the required depth of cultivation. The reduction indicators of trench depth that are dependent on changing the disc installation angle were also determined. The obtained dependencies, design and technological recommendations can be used in designing of planting machines for garden and forest crops, as well as in the justification of rational operating modes for them in intensive horticulture conditions. Full article

This study evaluated the agronomic performance of 15 plum cultivars grafted on both P. cerasifera and ‘Wangenheim Prune’ (P. domestica) seedling rootstocks over nine years at the Lithuanian Research Centre for Agriculture and Forestry. Trees on P. cerasifera were planted 4.5 m × 2.5 m apart, while those on ‘Wangenheim Prune’ were 4 m × 1.5 m apart. On average, trees on ‘Wangenheim Prune’ developed 23% smaller trunk diameters and produced 42% less pruning mass than those on P. cerasifera yet demonstrated higher yield efficiency, except for the ‘Valor’ cultivar, which performed better on P. cerasifera. Mean plot yield was about 40% higher on ‘Wangenheim Prune’. Based on productivity, survival, and fruit quality, the most promising cultivars for Nordic climates are ‘Čačanska Najbolja’ and ‘Jubileum’ on ‘Wangenheim Prune’, while ‘Valor’ was productive on both rootstocks. Leaf nutrient analyses revealed rootstock-dependent differences: leaves on P. cerasifera contained more P, K, Ca, and Mn, whereas Mg, Cu, and Zn were higher on ‘Wangenheim Prune’. Regardless of rootstock, trees grown in calcareous, high-pH soils were deficient in Fe and Mn. Full article

Cyclocarya paliurus (Batal.) Iljinsk is a multipurpose tree species with great potential for development. To identify indicators of grafting compatibility during the healing process, two cloned genotypes, CR4 and CR5, were used as scions, grafted onto seedling rootstocks derived from the Guangxi provenance. Following branch grafting, samples from the graft union were collected at 0, 20, 40, and 60 days. Physiological–biochemical indicators, including soluble sugars, soluble proteins, starch, peroxidase (POD) activity, polyphenol oxidase (PPO) activity, phenylalanine ammonia-lyase (PAL) activity, as well as flavonoid and phenylpropanoid contents, were analyzed. The graft survival rate of the CR4 combination (60%) was significantly higher than that of CR5 (35%). Significant differences in key physiological indicators were observed between the two scion–rootstock combinations. Analysis revealed that soluble sugar and soluble protein levels, along with POD and PAL activities in the scion during the early grafting stage, significantly influenced the final survival rate. Furthermore, lignans, lignin precursors, and several flavonoid compounds were found to accumulate preferentially at the graft union of the CR4 combination, which exhibited higher compatibility. These findings provide a physiological and biochemical foundation for selecting compatible scions and advancing clonal cultivation of C. paliurus. Full article

The utilization of cytoplasmic male sterility (CMS) is essential in hybrid seed production; however, its operational value in eggplant is insufficiently documented under practical conditions. This study compared CMS-based and conventional (non-CMS) hybridization systems with respect to flower production, flower functionality, and hybrid seed production efficiency, quantified as seed and viable seedling output per unit time, in three eggplant cultivars (‘Emi’, ‘Langada’, and ‘Tsakoniki’) in intra- and interspecific crosses. CMS did not affect total flower production or inflorescence architecture, which were primarily genotype-dependent. However, it altered flower opening, resulting in genotype- and position-dependent proportions of semi-opened and closed flowers at anthesis. Despite this effect, sufficient flowers suitable for hybridization remained available across all genotypes. CMS substantially simplified the hybridization process by eliminating emasculation, reducing flower manipulation time by approximately 55%, and increasing crossing rate by nearly twofold. Importantly, CMS did not negatively affect female fertility, as indicated by comparable percentages of successful crosses and high seed germination rates across cytoplasmic backgrounds. Seed production per fruit was moderately but significantly increased in intraspecific crosses, while it remained comparable between CMS and non-CMS systems for the interspecific crosses. As a result, CMS significantly increased hybrid seed output and effective seedling production per unit time in intraspecific crosses, while similar trends were observed in interspecific crosses, with gains ranging from 86% to 184% depending on genotype and pollen parent. Overall, this study demonstrates, from an operational perspective, that CMS enhances the efficiency of eggplant hybrid seed production by reducing labor requirements and increasing output per unit time without compromising reproductive performance. These findings highlight the practical value of CMS as a tool for improving hybrid seed production systems, including applications in both commercial hybrid development and rootstock breeding. Full article

Powdery mildew (PM) is a major fungal disease in cucumber (Cucumis sativus L.) cultivation. Grafting serves as an important agricultural practice for improving disease resistance and stress tolerance in scions. This study aimed to determine the effects of different pumpkin rootstocks on PM resistance in grafted cucumber plants. Susceptible ‘Xintai Mici’ cucumber scions were grafted onto 10 different pumpkin rootstock varieties, with self-grafted plants serving as the experimental control. Grafting significantly promoted plant biomass accumulation compared to the self-grafted control, and this enhancement was positively correlated with the rootstock’s root system size. However, grafted plant growth was still negatively affected by PM infection. Among the 10 rootstocks, seedlings grafted onto rootstock GP8 exhibited the lowest disease index, the slowest spore development, and the strongest PM resistance. While some resistant pumpkin rootstocks failed to confer significant PM resistance to their grafted cucumber scions, rootstock GP8 provided consistent PM resistance to its grafted plants. Furthermore, cucumber grafted onto rootstock GP8 showed a significantly enhanced net photosynthetic rate and increased antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, and glutathione reductase). Concurrently, these plants accumulated lower levels of superoxide anions and exhibited the smallest increases in malondialdehyde content among all the grafted combinations. Additionally, during PM infection, the expression levels of salicylic acid biosynthesis-related genes (CsICS1 and CsPAL) and downstream disease resistance genes (CsPR1, CsPR5, and CsNPR1) were significantly higher in scions grafted onto rootstock GP8 compared to self-grafted cucumbers. These results suggest that the enhanced PM resistance in grafted cucumber is significantly influenced by the rootstock, potentially through the regulation of photosynthetic performance, reactive oxygen species metabolism, and the expression of genes associated with the salicylic acid signaling pathway in the scion. Full article

Drought is a major limiting factor for apple growth and development. Abscisic acid (ABA) is a key hormone in plant abiotic stress responses, playing a vital role in mediating adaptation to drought. Malus sieversii, the wild ancestor of cultivated apple, exhibits superior drought tolerance. However, the specific ABA-dependent regulatory module underlying its exceptional drought tolerance remains to be elucidated. In this study, we investigated the role of ABA in the drought response of M. sieversii seedlings using a combination of exogenous ABA and the ABA biosynthesis inhibitor fluridone. Plants were subjected to four treatments: CK, PEG (20% PEG-6000), PEG+ABA (100 μM ABA) and PEG+FLU (100 μM fluridone). The results showed that ABA application significantly reduced the wilting rate by 45.53% and electrolyte leakage by 20.50% compared to the PEG treatment. Furthermore, it alleviated the decline in fresh weight and relative water content while reducing the accumulation of starch, sucrose, glucose, and fructose after seven days of stress. Conversely, FLU application intensified the adverse effects of drought. RNA-Seq analysis of the PEG+ABA vs. PEG comparison identified 5642 differentially expressed genes (DEGs), with significant enrichment in the starch and sucrose metabolism pathway, photosynthesis, carbon fixation, and MAPK signaling pathways. Exogenous ABA up-regulated BGLU23 while down-regulating BAM1. In contrast, no significant changes in their expression were observed under FLU treatment, suggesting their likely regulation in an ABA-dependent manner. In summary, ABA enhances osmotic-stress tolerance in M. sieversii through multiple pathways, among which starch and sucrose metabolism may represent a core and highly responsive regulatory pathway. Functional validation of key candidate genes BAM1 and BGLU23 remains an important direction for future investigation. These findings provide a theoretical basis for breeding drought-resistant apple rootstocks and for understanding ABA-mediated osmotic-stress tolerance mechanisms. Full article

Cucumber Fusarium wilt, which is induced by the soil-borne pathogen Fusarium oxysporum f. sp. Cucumerinum (FOC), represents a highly destructive disease. Cucumber seedling grafted onto figleaf gourd (Cucurbita ficifolia Bouché) rootstock (CFC) demonstrated better resistance to FOC. However, the molecular mechanism underlying this enhanced disease resistance capability is largely unknown. To elucidate this, we performed transcriptome, small RNA, and degradome sequencing for leaves from CFC and self-grafted cucumbers (SGC) as controls, with and without FOC infections, respectively. Our results indicated that three NAC genes, all predicted as targets of csa-miR164, were significantly up-regulated in CFC after FOC infection. Co-transformation assay in Nicotiana benthamiana confirmed that csa-miR164f directly inhibits NAC2, and transient overexpression of NAC2 in cucumber enhanced resistance to FOC, supporting its positive role in defense. Therefore, our results suggest that three NACs, upregulated in CFC, as an alternative pathway, enhance the reactive oxygen species burst and hypersensitive response, which further elevates the resistance to FOC infection. These results provide new insights into the molecular basis for improved FOC resistance in CFC. Full article

Tomato (Solanum lycopersicum L.) is an economically important horticultural crop. The application of mechanical grafting technology enables the efficient, large-scale production of grafted tomato seedlings, which is of great significance for overcoming continuous cropping obstacles and boosting tomato yield. In this study, tomato cultivar ‘Juxiang 1809’ as the scion and ‘T17-2’ as the rootstock were used to systematically investigate the effects of red-blue light quality pretreatments on tomato grafted seedlings. The rootstock and scion seedlings were cultivated under white (W), pure red (R), pure blue (B), and five mixed red-blue lights (R7B1, R3B1, R1B1, R1B3, R1B7). Our results demonstrated that R3B1 (Red: Blue = 3:1) yielded the highest scion comprehensive score (2.06), promoting balanced growth with robust stem diameter (2.75 mm) and high aboveground dry weight (0.36 g). For rootstocks, R3B1 also excelled, driving optimal root development with maximum root area (26.32 cm²) and dry weight (0.046 g). Post-grafting, R3B1-pre-treated seedlings maintained vigorous growth with enhanced photosynthetic capacity (37.10) and biomass accumulation. These findings demonstrate that R3B1 light quality is highly effective. It optimizes both scion vigor and rootstock root architecture. This offers a practical light-regulation strategy. It is applicable to the production of high-quality, machine-compatible tomato grafted seedlings in controlled environments. Full article

Walnut (Juglans regia L.) performance and sustainability are closely linked to soil–plant–microbe interactions; nowadays, the combined influence of edaphic context, plantation development and rootstock genotype on walnut-associated microbiomes remains insufficiently resolved. Here, we integrated soil physicochemical characterization, community-level physiological profiling and 16S rRNA gene amplicon sequencing across walnut plantations in four Spanish regions. The design included 14-year clonal stands (Galicia, Gerona, Toledo), an age gradient in Galicia (4, 9 and 14 years), and four rootstocks (MJ209, Vlach, own-rooted ‘Chandler’ and J. regia seedling) in the Córdoba plantation. At the community-level, rhizospheres exhibited higher overall metabolic activity, displaying substrate-specific functional fingerprints across regions. Regarding stand ages, a functional peak was observed at middle age, with a decline in richness and diversity with age. Moreover, rootstock genotype further modulated rhizosphere metabolic function. Sequencing supported compositional differences among regions, ages and rootstocks, identifying a bacterial core of Juglans spp. rhizosphere and detecting 36 putative Plant Growth-Promoting Rhizobacteria (PGPR) genera, suggesting a potential reservoir and possible uses in plant biotechnology. Overall, walnut-associated microbiomes are jointly structured by soil gradients, plantation development and rootstock genotype, supporting site and genotype-tailored microbiome management. Full article

As both an energy source and a signaling cue, light quality regulates graft healing by modulating endogenous phytohormone homeostasis, callus formation, and vascular reconnection. To elucidate the regulatory roles of red/blue (R/B) light ratios and green light supplementation on healing and seedling quality of grafted tomato (Solanum lycopersicum L.), a controlled-environment experiment was conducted in a plant factory using ‘Zhongza 105’ as the scion and ‘Zhezhen No. 1’ as the rootstock. LED lighting treatments were established with different R/B ratios (1.0, 2.5, 4.0, 5.5 and 7.0) with or without supplemental green light. The results show that moderate R/B ratios (4.0–5.5) significantly increased scion elongation, the stem diameter of both scion and rootstock, the mechanical strength of the graft union, and sap flow, while also enhancing leaf chlorophyll content, photosynthetic rate, and root activity. Under optimal R/B conditions, indole-3-acetic acid (IAA) and gibberellin (GA) levels were elevated, whereas abscisic acid (ABA) was reduced, favoring callus proliferation and vascular reconnection. Green light supplementation under moderate R/B further promoted stem thickening, leaf area expansion, water transport across the graft union, and total biomass accumulation. Overall, an R/B ratio of 4.0–5.5 combined with appropriate green light supplementation optimized the morphology, structure, and physiological performance of grafted tomato seedlings during the healing stage. The results aim to provide a scientific basis for optimizing light environments in a controlled environment, thus enhancing the stability and quality of grafted tomato seedlings. Full article

In tomato production, grafting enhances stress resistance, increases yield, and improves fruit quality. However, the selection of rootstock types limits its broader adoption. This study systematically evaluated the effects of grafting with 16 different rootstocks on tomato survival rate and yield. Fruits from four rootstocks, Gangshi 319 self-grafted (CK), Gangshi 319 seedlings (A), Torubam (T), and Fanzhen No. 1 (F), were further selected for fruit quality analysis and broad target metabolomics. The results showed that, except for Qiezhen No. 3 (QZ3), the graft survival rates of all rootstocks exceeded 95%. Grafting with rootstock F significantly increased yield per plant and soluble solids content, whereas rootstock T significantly reduced both traits. Broad target metabolomics analysis identified 18 major metabolite categories, including lipids, ketoaldehydes and esters, and terpenoids. KEGG pathway enrichment analysis revealed that differentially accumulated metabolites between the F and T treatments were primarily enriched in pathways such as the citric acid cycle, phenylpropanoid biosynthesis, glyoxylate and dicarboxylate metabolism, flavonoid biosynthesis, cysteine and methionine metabolism, and glycerophospholipid metabolism. These findings indicate that rootstock F effectively enhances tomato fruit yield and soluble solids accumulation by coordinating primary and secondary metabolism. This study provides important metabolic level insights for the selection and application of high quality and high yield tomato rootstocks in grafting. Full article

Soil salinization severely restricts the sustainable development of the pear industry. Pyrus betulifolia, a vital native salt-tolerant rootstock in China, holds great significance for investigating stress resistance mechanisms. Plant-specific DNA-binding One Zinc Finger (Dof) transcription factors act as pivotal regulators in stress adaptation. However, their functions in P. betulifolia remain largely unexplored. In this study, we identified 43 PbeDof members within the P. betulifolia genome and classified them into eight subfamilies via phylogenetic analysis. Gene structure and conserved motif analyses revealed that PbeDof members within the same subfamily share similar exon-intron organizations and protein architecture, suggesting evolutionary conservation. Promoter analysis indicated that PbeDof genes are rich in cis-acting elements related to light, phytohormones (especially ABA and MeJA), and stress responses, implying their potential roles in diverse biological processes. Chromosomal localization and collinearity analyses revealed that segmental duplication was the primary driver of this family’s expansion. Combined transcriptomic profiling and qRT-PCR assays demonstrated that PbeDof9.1 is predominantly expressed in roots and is strongly induced by salt stress. Subcellular localization confirmed that PbeDof9.1 targets the nucleus. Functional characterization indicated that heterologous overexpression of PbeDof9.1 in Arabidopsis thaliana significantly enhances salt tolerance at germination and seedling stages. Notably, under 175 mM NaCl stress, the transgenic lines exhibited a superior root system architecture, with primary root length and lateral root numbers being approximately 1.5-fold higher than those of the wild type. Furthermore, homologous overexpression in pear calli confirmed that PbeDof9.1 mitigates oxidative damage by boosting the activities of peroxidase (POD) and catalase (CAT) to scavenge reactive oxygen species (ROS), thereby reducing malondialdehyde (MDA) accumulation. Collectively, this study characterizes the PbeDof family and establishes PbeDof9.1 as a key candidate gene for the genetic improvement of salt tolerance in pear rootstocks. Full article

Potassium (K⁺) is essential for plant growth and development, influencing numerous physiological processes and stress responses. While the importance of K⁺ in overall plant performance is well-established, its specific effects on root system architecture and the underlying molecular mechanisms in woody perennials remain poorly understood. This knowledge gap is particularly significant for citrus rootstocks like trifoliate orange (Poncirus trifoliata L.), where root system optimization directly impacts drought resistance, nutrient acquisition, and overall orchard productivity. Here, we investigated how varying K⁺ concentrations (K₀, K₂, K₆, and K₁₂) affect trifoliate orange seedling development by comprehensively analyzing root architecture parameters, root hair morphology, endogenous hormone levels, and expression patterns of cell-wall-modifying and auxin-related genes. We found that moderate K⁺ levels (K₆) optimized root architectural development while both deficiency (K₀, K₂) and excess (K₁₂) inhibited overall growth and root architecture but enhanced root hair development. This morphological dichotomy corresponded to distinct hormonal profiles, showing reduced auxin (IAA), gibberellins (GAs), and zeatin riboside (ZR) levels under K⁺ stress conditions. Gene expression analysis revealed significant upregulation of expansins (PtEXPA4, PtEXPA5, PtEXPA7) and reconfiguration of auxin biosynthesis (TAA/TAR/YUC) and transport (AUX/LAX/ABCB/PIN) machinery under non-optimal K⁺ conditions. Our findings suggest that K⁺ availability modulates trifoliate orange root development through coordinated regulation of hormone homeostasis and gene expression, particularly within the auxin signaling network. These findings elucidate K⁺-responsive root developmental plasticity as a potential adaptive strategy, providing valuable insights for optimizing fertilization strategies in citrus cultivation and identifying potential molecular targets for enhancing potassium use efficiency in woody perennials. Full article

Trifoliate orange (Poncirus trifoliata L.) is one of the most widely utilized rootstocks in citrus production; however, it exhibits a relatively high sensitivity to salt stress. When cultivated in salinized soil, it frequently develops nutrient uptake disorders, leaf chlorosis, as well as reduced fruit yield and quality. To enhance the salt stress tolerance of citrus plants, this study investigated the effects of Trichoderma harzianum inoculation on the growth and response mechanisms of citrus seedlings under salt stress conditions. The results showed that salt stress significantly inhibited the growth of citrus seedlings, while T. harzianum inoculation effectively alleviated the inhibitory effect. After treatment with T. harzianum, the plant height, stem diameter, leaf number, and biomass of citrus seedlings increased significantly. The net photosynthetic rate, stomatal conductance, intercellular CO₂ concentration, transpiration rate, and chlorophyll content were significantly increased by T. harzianum inoculation. Meanwhile, T. harzianum inoculation increased the content of nitrogen, phosphorus, calcium, magnesium, zinc, and copper, and decreased sodium content in citrus seedlings. In addition, T. harzianum inoculation significantly up-regulated the expression of stress-responsive genes such as SOSs, PIPs, TIP1, TIP4, and TIP9. In conclusion, T. harzianum inoculation improved the salt stress tolerance of citrus seedlings through increasing photosynthetic efficiency, promoting nutrient absorption, sodium efflux, and water utilization via up-regulating the expression of SOSs and aquaporin genes. Full article

Carpinus betulus is an important ornamental landscape tree species with colorful foliage. It is widely used in landscaping due to its upright tree shape, significant seasonal changes, and good tolerance to pruning. Propagation methods for C. betulus include grafting, cutting, and seeding. However, the germination rate of seeding is low, and the rooting of cuttings is difficult; moreover, plant tissue culture techniques are complex, and the key technologies have not been disclosed. Grafting has therefore become the primary means of propagation. However, enabling the rapid reproduction of C. betulus through appropriate grafting methods and in appropriate environments remains an urgent issue to be addressed. In this study, Carpinus turczaninowii was used as a rootstock to graft C. betulus, and the effects of the grafting periods, technique, and environmental conditions on the survival rate of grafted C. betulus were discussed. The results showed that branch grafting (cleft graft and whip-and-tongue graft) performed in March to April and August to November resulted in the highest survival rates, whereas budding grafts (chip budding and patch budding) were more suitable in May and June. Increasing ambient humidity was a key measure for improving graft survival rates and germination rates. In terms of grafting survival rate, germination rate, and leaf growth, humidification and treatment with 60–70% light transmission had better results than treatment with natural humidity or 20–30% light transmission and full light treatment under humidification conditions. Under low-light conditions, increasing air humidity had a particularly pronounced effect on promoting the growth of grafted seedling branches. In the future, further research should be conducted on the molecular mechanism mediated by soil environment and temperature changes for the successful grafting of C. betulus, providing a theoretical basis for the propagation and cultivation of C. betulus. Full article