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Root regeneration is an important factor influencing the healing rate of graft union and the survival of double-root-cutting grafting. To date, little information is available on how to enhance root regeneration of rootstock in grafted watermelon (Citrullus lanatus) seedlings. In this study, the effects of different light treatments on root regeneration were determined. This revealed that addition of far-red light (Fr) could significantly expedite root formation in the rootstock. Moreover, the results of transcriptome analysis revealed that plant hormone pathway and auxin-related genes were greatly induced by Fr, especially for auxin-response proteins (including CmIAA11, CmIAA17, and CmAUX28), Small auxin-up RNA genes (including CmSAUR20 and CmSAUR50) and the auxin efflux transporter (CmPIN3). In addition, the expression of Phytochrome Interacting Factor (PIFs), such as CmPIF1, CmPIF3 and CmPIF7, was remarkably increased by Fr. These genes may act together to activate auxinrelated pathways under Fr treatment. Based on the results of HPLC-MS/MS analysis, the concentrations of different auxin-types in adventitious root were significantly influenced by Fr. Furthermore, the better growth of rootstock root displayed superior vasculature transport activity of the graft union with Fr treatment, which was determined by the acid magenta dyeing experiment. Therefore, all the results suggested that Fr could induce AR formation in rootstocks, which may be associated with the auxin accumulation by regulating the transcriptional level of auxin-related and PIF genes. The findings of this study demonstrated a practicable way to shorten the healing period of graftings and improve the quality of grafted watermelon seedlings, which will provide a theoretical basis for the speeding development of industrialized seedlings production. [ABSTRACT FROM AUTHOR]

Pink pine nut, a dried fruit, is produced by a Mexican pine species. However, unlike other nuts, the lack of management practices and the absence of grafting techniques hinder its production. This work evaluated the behavior and growth of Pinus cembroides (PC) and P. orizabensis (PO) grafted onto four rootstocks. Two trials were conducted in April and June 2020 with PC and PO scions. The rootstocks used were PC, P. patula (PP), P. teocote (PT), and P. greggii var. australis (PG). The variables evaluated were engraftment (%), height increase (HI), scion diameter (SD), rootstock diameter (RD), scion-rootstock ratio (SRR), survival (%), and number of shoots (NS). No statistical analyses were performed for engraftment, survival, and SRR; for HI, SD, and RD, a mean comparison was performed (Tukey ≤ 0.05), and NB was analyzed by Poisson regression. In the first trial, successful engraftment varied from 45.5 to 100%; in the second trial, the range was from 73.3 to 100%. In terms of height, the PO/PC combination reached 21.14 cm, and the PC/PC combination measured 17.69 cm for April and June. The average survival was 60.42% for the first experiment; for the second experiment, only two combinations (PC/PG and PC/PC) survived with an average of 75.85%. Thus, it is possible to implement the grafting technique in pine nut species. This is the first work reporting successful grafting for this species, focusing on seed production. [ABSTRACT FROM AUTHOR]

ABSTRACT African horned melon (Cucumis metuliferus E. Meyer ex Naudin, 2n = 2x = 24) is an under‐researched and under‐utilised cucurbit crop primarily grown for its nutritious fruit. In its centre of diversity, the crop is valued for its relatively high tolerance to insect pests, diseases, drought and heat stress. It is a potential opportunity crop and a valuable source of genes to major Cucumis species, including cucumber (Cucumis sativas L.) and melon (C. melo L.). Its climate resilience and nutrient‐rich fruit provide niche market opportunities. Hence, production and value‐adding will make African horned melon a crop of choice globally. There is a need for an in‐depth investigation into the genetic diversity, breeding and food composition of the crop. Therefore, the objective of this review was to provide perspectives on the production and breeding status of African horned melon to appraise its genetic value for human welfare, strategic production, genetic conservation and breeding of market‐preferred varieties, including closely related Cucumis species. The first section described the botany, production status, germplasm resources and characterisation based on phenotypic and genetic markers. This is followed by breeding progress for biotic and abiotic stress tolerance, utilities and challenges of gene transfer and potential rootstock to Cucumis species, especially cucumber and melon. The review summarised the main breeding goals and approaches, including mutation breeding to fast‐track the development of new varieties. Information presented in the review will guide cultivar design in African horned melon or related cucurbits, aiming for superior agronomic and nutritional quality traits and tolerance to biotic and abiotic stresses. [ABSTRACT FROM AUTHOR]

Background: Root plays an important role in the growth and development of fruit trees; however, the molecular mechanisms behind the differences among rootstock varie-ties remain unclear. Methods: This study examined the effects of different rootstocks on root structure and the endogenous hormone content of 1-year old apple seedlings in combinations of Tianhong 2 (T2)/Malus robusta (HT), T2/G935, and T2/Jizhen 2 (J2). Results: The results showed that the T2/HT treatment had greater root length, surface area, volume, average diameter, tips and forks, followed by G935 and J2. In T2/HT leaves and roots, the indole-3-acetic acid (IAA) and gibberellins (GA3) levels were highest, and the abscisic acid (ABA) levels were the lowest. A root transcriptome analysis detected 10,064, 10,511, and 8,719 differentially expressed genes in T2/HT vs. T2/G935, T2/HT vs. T2/J2, and T2/J2 vs. T2/G935, respectively. The analysis of Gene Ontology (GO) terms indicated a significant enrichment in biological processes, cellular components, and molecular functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that plant hormone signaling, MAPK signaling pathway–plant, and plant–pathogen interaction played important roles in differences in the rooting ability of different rootstocks. In addition, some key differential genes were associated with root growth and development and were involved in these metabolic pathways. This study is important for enriching theoretical studies of fruit tree roots. [ABSTRACT FROM AUTHOR]

Drought is a major stress that hinders plant growth and causes water stress, posing a significant threat to global food security. While nanotechnology, particularly the use of nanoparticles such as TiO2, offers a promising solution by enhancing plants' resilience to drought stress, improving nutrient absorption, and promoting growth under adverse conditions, its application in viticulture remains underexplored. The objective of this research was to investigate the effects of titanium dioxide nanoparticles (TiO2-NPs; 100, 10, 1, and 0 ppm (control)) on various physiological, biochemical, and morphological parameters in grapevine saplings. Three different rootstock varieties, 41 B/Crimson Seedless (CS), 1103 P/CS, and 5 BB/CS, were included in the experiment to assess how rootstock variety influences the response of grapevine saplings to TiO2-NPs under drought stress (40–50%) and well-irrigated (90–100%) conditions. Young vines grown in pots under greenhouse conditions were used in this study. Applications of 10 ppm TiO2-NPs improved growth parameters and the SPAD index and enhanced stomatal conductance, relative water content, and protein content in grapevine saplings under both drought and well-irrigated conditions. Conversely, oxidative stress parameters, including the membrane damage index, hydrogen peroxide, drought index, and lipid peroxidation levels, were significantly reduced following 10 ppm TiO2-NP applications under drought conditions. Furthermore, total phenolic content, proline content, and ascorbate peroxidase, catalase, and superoxide dismutase activities, which increased significantly with drought stress, were reduced to lower levels, paralleling the alleviation of drought-induced oxidative stress. Our results suggest that the primary role of TiO2 nanoparticles in enhancing drought tolerance is due to their beneficial effects in alleviating damage caused by drought stress. This finding applies not only to grapevines but may also be relevant for other agricultural crops. [ABSTRACT FROM AUTHOR]

Pistacia genus is botanically classified in the Sapindales order and the Anacardiaceae family, and the member of this genus P. eurycarpa is used as a rootstock for pistachio. Due to its rich oil content, various soaps are produced from the green peels of P. eurycarpa nuts and are used in the cosmetic industry as soap. In the current study, we aimed to release the complete chloroplast genome of P. eurycarpa to detect the relationship of the members of the Sapindales and also Pistacia genus. The length of the chloroplast genome of P. eurycarpa was identified 160,693 (bp) and consisted of the distinct parts of the genomic fragments such as LSC, SSC, and IR regions. The length of the LSC was 88,410 (bp), and SSC genomic range represented a total of 19,087 (bp). Inverted regions length was 26,598 (bp). A total of 125 genes were determined within the whole chloroplast genome of P. eurycarpa. The number of simple sequence repeats (SSRs) in the chloroplast genome was computed as 74. Three main clusters defined the dendrogram of all accessions. The closest pairs of species were identified among the P. eurycarpa and P. vera species. The farthest genetic relationship was calculated among the members of the Sapindales species Mangifera indica and the Fagales species Castanea mollissima. The sequences of the chloroplast genome of P. eurycarpa species can be evaluated for the construction of the basis of the complete evolution of the order, genera, and the development of the SSRs for species-specific markers for revealing the evolution of Pistacia species for future breeding research. [ABSTRACT FROM AUTHOR]

[Objective] To study the effect of Daqingye rootstock on flowering time and cold resistance of Cerasus campanulata strain. [Method] From 2019 to 2021, the grafted seedlings of four varieties of Cerasus campanulata strain were used as control, and the grafted seedlings of the above varieties of Daqingye rootstock were observed. The four varieties were Cerasus campanulata ‘Hongfenjiaren’, Cerasus campanulata ‘Zhongguohong’, Cerasus campanulata ‘Kawazu-zakura’ and Cerasus campanulata ‘Double-flowered’. The difference of flowering time and the phenomenon of branch drying of annual branches were compared. Physiological indexes such as malondialdehyde (MDA) content, soluble protein content, proline content and superoxide dismutase (SOD) activity were determined under low temperature stress of 0, -5, -10, -15 and -20 ℃, respectively, and the membership function method was used for comprehensive evaluation. [Result] The results showed that the first flowering time of the grafted seedlings of Daqingye rootstock of the above four varieties was 8. 7 days, 8. 3 days, 7. 3 days and 6. 3 days later than that of the grafted seedlings of Cerasus campanulata rootstock, respectively. Under the condition of overwintering in the open field, the phenomenon of branch drying of other seedlings was more serious except for the slight phenomenon of branch drying of Cerasus campanulata ‘Kawazu-zakura’ of Daqingye rootstock. With the decrease of temperature, MDA content and soluble protein content of all seedlings continued to increase, and proline content and SOD activity showed a trend of first increasing and then decreasing. The membership function analysis showed that the cold resistance ability of the grafted seedlings of the four varieties of Daqingye rootstock ranked high. [Conclusion] Compared with the grafted seedlings of Cerasus campanulata rootstock, the grafted seedlings of Daqingye rootstock had a later flowering time and a stronger cold resistance, and Cerasus campanulata ‘Kawazu-zakura’ of Daqingye rootstock could overwinter in the open field in the areas with good small environment in Beijing. [ABSTRACT FROM AUTHOR]

The propagation of citrus seedlings is accomplished through grafting, utilizing seeds for the production of rootstocks. The germination of certain seeds may be low and uneven, complicating the production of high-quality seedlings. The use of plant growth regulators (PGRs) is a viable alternative to improve the quality of seedling production, as these compounds can break dormancy, control the hydrolysis of reserves, induce cell division, and regulate permeability and protein functions. This study aimed to evaluate the germination of seeds and the growth of Rangpur lime (Citrus limonia L. Osbeck) seedlings under the influence of imbibition in solutions of gibberellic acid (GA3) and a combination of GA4+7 + 6Benzyladenine. The experiment was conducted under controlled laboratory and greenhouse conditions, using a completely randomized design in a 2 × 5 factorial scheme, with two types of plant regulators (GA3 and GA4+7 + 6BA) at five concentrations (0, 250, 500, 750, and 1000 mg L−1 a.i.). Quantitative and qualitative variables were evaluated, ranging from seed germination to seedling development and formation, including germination percentage and speed index, fresh and dry biomass of roots and shoots, enzymatic activity, and gas exchange. The results indicate that GA3 significantly accelerates the germination process of Rangpur lime cv. Santa Cruz seeds and promotes better seedling growth and development, resulting in vigorous seedlings. These findings demonstrate that the application of PGRs, particularly GA3, can substantially enhance the propagation efficiency of citrus rootstocks, offering a practical solution for improving the uniformity and quality of seedling production in commercial settings. [ABSTRACT FROM AUTHOR]

The symptoms of huanglongbing (HLB), a disease caused by the bacterium Candidatus Liberibacter asiaticus (CLas), are visible on the canopy of citrus plants. They include mottling of leaves followed by dropping and lopsided fruits with premature dropping. Loss in phloem functionality and degradation of the root system are also HLB symptoms with a severe impact on plant growth and production. Some Citrus relatives, such as Poncirus trifoliata and its hybrids, have shown more tolerance to HLB disease and low titers of CLas compared to Citrus species, but little is known about the effects of CLas on their root system. In this study, we investigated the effects of CLas-infected 'Valencia' scion on the citrandarin IAC3222 (a hybrid between P. trifoliata and Sunki mandarin) used as rootstock as well as interstock between 'Valencia' and Swingle citrumelo rootstock. At 13 months post-inoculation, the cycle threshold values (CT) for CLas in the infected scion samples indicated a high CLas titer (from 15.9 to 22.7) regardless of the rootstock variety or interstock used. However, no CLas-positive samples were detected in the roots of IAC3222 (CT ranging from 37.9 to 40.0), in contrast to all Swingle roots (CT ranging from 27.9 to 31.3). Both root volume and mass were reduced in IAC3222 compared to uninfected 'Valencia' scion, suggesting that scion infection damages roots, regardless of whether they are contaminated or not by CLas. The damage to the root system of IAC3222 was significantly less severe than that of the Swingle rootstock. Multivariate hierarchical analysis considering all evaluated parameters clustered the CLas-infected plants grafted on IAC3222 together with the non-inoculated plants. We concluded that the IAC3222 rootstock was less affected by the CLas-infected scion compared to the Swingle rootstock and is a promising rootstock to minimize the HLB effect on plant development. [ABSTRACT FROM AUTHOR]

The paper presents the possibilities of energy management of residues from the production of ‘Regent’ grapevines. Field tests were conducted under conditions of temperate climate in 2022 on six types of rootstocks viz: 101-14, 125 AA, 161-49, 5 BB, SO4, SORI, the control were ungrafted vines growing on their own roots. The study analysed the following crop parameters, i.e. number and mass of grapes, number and mass of berries; quality parameters of woody shoots. Technical and elemental analysis was performed, and the heat of combustion and calorific value were determined to define fuel quality parameters. In addition, emission factors of CO, CO2, SO2, NOx and ash were estimated to demonstrate the degree of impact of potential bio-residue from the combustion process. An assessment was made on the basis of stoichiometric equations of flue gas composition, as well as theoretical oxygen demand and total fuel gas volume. The study showed that cultivation on 125 AA rootstock is characterised by obtaining significantly the highest yield, shoot mass and bio-residues suitability for energy purposes. The research showed that the most effective in practical cultivation is the use of SORI and SO4 rootstocks in cultivation, which are characterised by average parameters of obtained yield, growth value and fuel.

Main Conclusion: The dwarfing mechanism in apple clonal rootstocks is driven by complex interactions between anatomical, hormonal, genetic, and phenolic factors, offering potential for advanced genetic manipulation to optimize tree size and enhance orchard productivity. The widespread adoption of dwarfing rootstocks is pivotal to modern commercial apple (Malus × domestica Borkh) orchards due to their ability to control tree size, shorten the juvenile period, and enhance reproductive growth and overall productivity. The underlying mechanisms of rootstock-induced dwarfism are multifaceted and involve interactions between phenotypic, anatomical, genetic, and phytohormonal factors. This review consolidates current understanding, highlighting the importance of auxin (IAA), cytokinins (CKs), gibberellins (GAs), and abscisic acid (ABA) in mediating growth suppression through impaired transport and hormone signaling. The phenotypic impacts, including reduced root growth, shorter sylleptic shoots, and higher floral bud densities, are discussed alongside genetic loci such as Dw1, Dw2, and Dw3, and the influence of key genes/TFs like MdWRKY9, RGL, and PIN. Anatomically, dwarf rootstocks exhibit a higher bark-to-wood ratio and restricted hydraulic conductivity, which contribute to reduced scion vigour. Furthermore, the accumulation of phenolic compounds in the graft union of dwarfing rootstocks further modulates the growth inhibition. These insights lay the groundwork for advanced molecular breeding strategies, incorporating gene-editing technologies to improve dwarf rootstock development, providing avenues for enhanced orchard management and apple productivity. [ABSTRACT FROM AUTHOR]

Abstract Salinity stress poses a significant treat to crop yields and product quality worldwide. Application of a humic acid bio stimulant and grafting onto tolerant rootstocks can both be considered sustainable agronomic practices that can effectively ameliorate the negative effects of salinity stress. This study aimed to assess the above mentioned ameliorative effects of both practices on cucumber plants subjected to saline environments. To attain this goal a factorial experiment was carried out in the form of a completely randomized design with three replications. The three factors considered were (a) three different salinity levels (0, 5, and 10 dS m−1 of NaCl), (b) foliar application of humic acid at three levels (0, 100, and 200 mg L−1), and (c) both grafted and ungrafted plants. Vegetative traits including plant height, fresh and dry weight and number of leaf exhibited a significant decrease under increasing salinity stress. However, the application of humic acid at both levels mitigated these effects compared to control plants. The reduction in relative water content (RWC) of the leaf caused by salinity, was compensated by the application of humic acid and grafting. Thus, the highest RWC (86.65%) was observed in grafting plants with 0 dS m−1 of NaCl and 20 mg L−1 of humic acid. Electrolyte leakage (EL) increased under salinity stress, but the application of humic acid and grafting improved this trait and the lowest amount of EL (26.95%) was in grafting plants with 0 dS m−1 of NaCl and 20 mg L−1 of humic acid. The highest amount of catalase (0.53 mmol H2O2 g−1 fw min−1) and peroxidase (12.290 mmol H2O2 g−1 fw min−1) enzymes were observed in the treatment of 10 dS m−1 of NaCl and 200 mg L−1 humic acid. The highest amount of total phenol (1.99 mg g−1 FW), total flavonoid (0.486 mg g−1 FW), total soluble carbohydrate (30.80 mg g−1 FW), soluble protein (34.56 mg g−1 FW), proline (3.86 µg g−1 FW) was in grafting plants with 0 dS m−1 of NaCl and 200 mg L−1 of humic acid. Phenolic acids and phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) enzymes increased with increasing salinity and humic acid levels. Contrary to humic acid, salt stress increased the sodium (Na+) and chlorine (Cl−) and decreased the amount of potassium (K+) and calcium (Ca2+) in the root and leaf of ungrafted cucumber. However, the application 200 mg L−1 humic acid appeared to mitigate these effects, thereby suggesting a potential role in moderating physiological processes and improving growth of cucumber plants subjected to salinity stress. According to the obtained results, spraying of humic acid (200 mg L−1) and the use of salt resistant rootstocks are recommended to increase tolerance to salt stress in cucumber. These results, for the first time, clearly demonstrated that fig leaf gourd a new highly salt-tolerant rootstock, enhances salt tolerance and improves yield and quality of grafted cucumber plants by reducing sodium transport to the shoot and increasing the amount of compatible osmolytes.

Rose plants that produce cut flowers require a sturdy and high-quality rootstock. However, propagation of stem cuttings often fails to grow roots if the supporting factors are not considered. Generally propagation of rootstock roses is done vegetatively through stem cuttings. One of the supports for the success of rose cuttings as rootstocks is good root growth. The success of root growth can be supported by external factors such as growth regulators and suitable planting media. The purpose of this research was to study the effectiveness of using natural growth regulators and planting media as external factors that can increase the growth of rose cuttings. The materials needed include rose stems, shallot bulbs, mung bean sprouts, young corn, Indole Acetic Acid (IAA) 99%, dark glass bottles, rotary evaporator, methanol, filter paper, distilled water, paper envelopes, soil, husks charcoal and bokashi fertilizer. The research was conducted in Dadaprejo Village, Junrejo District, Batu City, East Java from March to June 2023. The data obtained was analyzed for variance (ANOVA) 5%, if a significant effect is obtained it is continued with a 5% honest significant difference test (BNJ). The use of growth regulators together with the planting medium provides an interaction with the time of shoot emergence. The application of shallot extract can be used as a natural growth regulator to increase the length of shoots and the number of leaves. The use of rice husk charcoal as a planting medium increases the number of roots, root length and time of shoots emergence. The mixed treatment of planting media gave good results on the number of shoots of rose cuttings compared to the treatment of one type of growing media. While the treatment of a mixture of soil planting media + bokashi fertilizer gave good results on fresh weight, dry weight and shoot length of plants. [ABSTRACT FROM AUTHOR]

Drought stress is one of the most important limitations in the production of agricultural products and especially horticulture in different parts of the world and Iran. The climate changes that have happened in the last few years, it is possible to provide sustainable production of grapes in water stress conditions by examining and selecting cultivars that tolerate to drought stress. For this purpose, an experiment from 2018 to 2022 in the form of split plots in the form of randomized complete blocks with 3 replications in garden conditions to investigate the effect of changes in soil water potential on the morphological, physiological and biochemical characteristics of grafted cuttings on cultivar traits Tolerant to sensitive 7 grape (Vitis vinifera L.) cultivars were carried out. The treatments included 7 selected grape varieties (‘Bidaneh Ghermez’, ‘Bidaneh Sefid’, ‘Rashe’, ‘Sahani’, ‘Kare Royeh’, ‘Moulai’, and ‘Chafte’) as the base and red quince cultivar as scion and three levels of drought stress including humidity. Agricultural (control), 75% (moderate stress) and 55% (severe stress) were based on agricultural moisture discharge. The results showed that with more severe water stress, the amount of proline, ABA, activity of catalase and peroxidase, the expression of CBF4, NCED3, and DHN1 genes increased, as well as the amount of total chlorophyll were decreased. In this experiment, the highest proline, abscisic acid, catalase, peroxidase, NCED3, CBF4 and DHN1 gene expression were observed in this experiment under severe stress treatment. In general, ‘Bidaneh Ghermez’ cultivar grafted on the rootstocks of ‘Chafte’, ‘Moulai’ and ‘Kare Royeh’ had a higher potential for tolerance to drought stress than other grafted combinations tested in most of the traits. [ABSTRACT FROM AUTHOR]

Simple Summary: Climate change poses a significant threat to agriculture, primarily through the increased frequency and severity of droughts. These extreme weather conditions reduce water availability, impacting crop yields and biomass production. Drought stress is particularly challenging for regions already prone to water scarcity, compromising food security. Addressing these issues requires innovative strategies and a thorough understanding of plant responses to water deficit conditions. This study aims to unravel the molecular mechanisms underlying drought tolerance in Citrus, crucial for developing adaptive strategies. The findings show that Bitters (C22) exhibits greater drought tolerance than Carrizo Citrange and identify key genes involved in responding to water scarcity. In conclusion, this research enhances our understanding of how citrus plants respond to water stress and identifies promising candidate genes. These insights will guide future research aimed at developing drought-tolerant plants. Agriculture faces the dual challenge of increasing food production and safeguarding the environment. Climate change exacerbates this challenge, reducing crop yield and biomass due to drought stress, especially in semi-arid regions where Citrus plants are cultivated. Understanding the molecular mechanisms underlying drought tolerance in Citrus is crucial for developing adaptive strategies. Plants of two citrus rootstocks, Carrizo Citrange and Bitters (C22), were grown in aerated half-strength Hoagland's nutrient solution. Post-acclimation, the plants were exposed to a solution containing 0% (control) or 15% PEG-8000 for 10 days. Leaf malonyl dialdehyde (MDA) and hydrogen peroxide (H2O2) content were measured to assess the reached oxidative stress level. Total RNA was extracted, sequenced, and de novo-assembled. Weighted Gene Correlation Network Analysis (WGCNA) was conducted to examine the relationship between gene expression patterns and the levels of MDA and H2O2 used as oxidative stress indicators. Plant visual inspection and MDA and H2O2 contents clearly indicate that Bitters is more tolerant than Carrizo towards PEG-induced drought stress. RNA-Seq analysis revealed a significantly higher number of differentially expressed genes (DEGs) in Carrizo (6092) than in Bitters (320), with most being associated with drought sensing, ROS scavenging, osmolyte biosynthesis, and cell wall metabolism. Moreover, the WGCNA identified transcription factors significantly correlated with MDA and H2O2 levels, thus providing insights into drought-coping strategies and offering candidate genes for enhancing citrus drought tolerance. [ABSTRACT FROM AUTHOR]

Health and quality of the root system are imperative to ensure the successful establishment of a citrus tree after transplant from the nursery into the field. Containerized citrus production in enclosed nurseries restricts root growth and can result in root circling and intertwining. This may hinder root expansion and result in root girdling after transplant, negatively affecting tree establishment and growth. The root structure of a transplanted citrus tree can also be affected by the container type used in the nursery. Containers with root-pruning properties like chemical pruning or air pruning reduce root circling and may produce superior root systems compared with regular, nonpruning containers. The aim of this study was to evaluate the effects of different nursery containers on root physiological and morphological traits and plant performance over 15 months of growth in the nursery. Three container types, chemical pruning containers, air-pruning containers, and standard nursery containers, were compared. The chemical pruning containers were standard citrus nursery containers with a mixture of copy hydroxide [Cu(OH)2] and copper carbonate (CuCO3) [10% copper (Cu)] applied to the inner wall. Pruning occurs upon contact of the roots with the Cu on the wall of the containers. The air-pruning containers were customsized Air-Pots in which pruning occurs on holes in the wall of the containers upon contact of the roots with the air. Two rootstocks, US-812 and US-942 (Citrus reticulata × Poncirus trifoliata), were included for comparison in the nongrafted stage and 12 months after grafting with 'Valencia' orange (Citrus sinensis). Chemical root pruning positively influenced tree height, shoot mass, leaf area, rootstock trunk diameter, and the nonfibrous root biomass. No differences among container types were observed for the fibrous root biomass, but chemical pruning produced more roots that were finer with a higher specific root length and a higher respiration rate. In contrast, air pruning produced more roots that were thicker compared with the other containers. Most of the leaf nutrients were lower in trees grown in the chemical pruning containers compared with the standard containers, except for Cu and zinc (Zn), which were highest in the former. Trees growing in air-pruning containers were not significantly different in growth from trees growing in standard containers. [ABSTRACT FROM AUTHOR]

In the framework of our studies on Citrus cultivars in Greece, the chemical composition of the essential oils (EOs) from the peels and leaves of orange, pummelo, and tangelo (mandarin × grapefruit hybrid) cultivated in Greece have been studied. All EOs have been analyzed through GC-MS, and a total of 47 and 87 metabolites were identified in the peels and leaves, respectively. These metabolites are classified into the chemical groups of terpenes, alcohols, aldehydes, esters, ketones, and organic acids. Limonene was the most abundant compound in the peel EOs. Moreover, bioactive polymethoxyflavones (PMFs) were isolated and structurally determined from the peels of orange and tangelo, highlighting them as a good potential source of natural PMFs. All EOs were evaluated for their antimicrobial activity against nine human pathogenic microorganisms (six bacteria and three fungi), showing an interesting profile. The EOs from the peels of all Citrus species exhibited a stronger antimicrobial activity compared to those from the leaves. The susceptibility of the assayed Gram-positive bacteria was observed to be greater than that of Gram-negative bacteria, while the fungi were also relatively less resistant than bacteria. The rootstock choice did not influence the EO profile of the fruit peel but exerted an influence on the chemical profile of the leaves. [ABSTRACT FROM AUTHOR]

A greater genetic diversity is essential for disease resistance in particular, and intergeneric hybridization makes this possible. The genus Cydomalus (syn: Cydolus), which is frequently used as rootstock, was derived from intergeneric hybridization between Cydonia oblonga Mill. and Malus domestica Borkh in Moldova and Bulgaria. It is known that hybrids from this genus exhibit quince and/or apple characteristics and some of them have been identified with reddish fruit skin color in Türkiye in the last decade. Erwinia amylovora Burril. is the most devastating bacterial disease in the Rosaceae family, and there have been no reports of Cydomalus. In this study, fire blight susceptibility index of three Cydomalus genotypes, were collected from İzmir and Manisa provinces, and two important quince rootstocks were determined by artificial inoculations with the most virulent Erwinia amylovora strain of our collection, under greenhouse conditions for two consecutive years. In addition, susceptibility levels of two Cydomalus genotypes were observed under natural disease pressure habitats. In line with the results of artificial inoculations, two of Cydomalus genotypes were determined to be more tolerant to fire blight disease than quince rootstocks and these genotypes could be used in breeding studies. Moreover, Cydomalus genus was identified as the new host for Erwinia amylovora. [ABSTRACT FROM AUTHOR]

Grapevine rootstocks are gaining importance in viticulture as a strategy to combat abiotic challenges, as well as enhance scion physiology. Direct leaf-level physiological parameters like net assimilation rate, stomatal conductance to water vapor, quantum yield of PSII, and transpiration can illuminate the rootstock effect on scion physiology. However, these measures are time-consuming and limited to leaf-level analysis. This study used different rootstocks to investigate the potential application of aerial hyperspectral imagery in the estimation of canopy level measurements. A statistical framework was developed as an ensemble stacked regression (REGST) that aggregated five different individual machine learning algorithms: Least absolute shrinkage and selection operator (Lasso), Partial least squares regression (PLSR), Ridge regression (RR), Elastic net (ENET), and Principal component regression (PCR) to optimize high-throughput assessment of vine physiology. In addition, a Convolutional Neural Network (CNN) algorithm was integrated into an existing REGST, forming a hybrid CNN-REGST model with the aim of capturing patterns from the hyperspectral signal. Based on the findings, the performance of individual base models exhibited variable prediction accuracies. In most cases, Ridge Regression (RR) demonstrated the lowest test Root Mean Squared Error (RMSE). The ensemble stacked regression model (REGST) outperformed the individual machine learning algorithms with an increase in R2 by (0.03 to 0.1). The performances of CNN-REGST and REGST were similar in estimating the four different traits. Overall, these models were able to explain approximately 55–67% of the variation in the actual ground-truth data. This study suggests that hyperspectral features integrated with powerful AI approaches show great potential in tracing functional traits in grapevines. [ABSTRACT FROM AUTHOR]

Grafting alters the genetic and anatomical features of plants. Although grafting has been widely applied in plant propagation, the underlying processes that govern the effects of the procedure are not fully understood. Samples were collected to study the long-term influence of grafting on the leaf-shoot morphology, leaf-shoot anatomy, and genetic signature of the grafted plants. Citrulus lanatus (Thunb.) Matsum. & Nakai (cv. Lady) was used as the scion, and Lagenaria siceraria (Molina) Standl (cv. Argentario) as a rootstock. In grafted plants, leaf blades and petioles were 20.92% and 12.82% longer, respectively, while the midrib collenchyma was 35.68% thicker, and the diameter of the vessel member was 11.17% larger than in ungrafted plants. In the stem, grafting affected the arrangement and number of vascular bundles (from 1 to 2 rings). The thickness of the epidermis decreased by 69.79%, and the size of the external fascicular phloem decreased by 23.56%. The diameter of the vessel member of the grafted plants increased by 28.94%. Eight out of ten evaluated primers met the requirements (stability in both watermelons and bottle gourd, tissue-specific). In the genetic tests, we examined whether this change in the gene expression pattern is due to the grafting and, if so, to what extent. Seven out of eight tested Small Auxin Up-Regulated RNA (SAUR) genes were expressed in the ungrafted and grafted C. lanatus lines in four cases; the expression increased by more than 10% after grafting. The morpho-anatomical changes and genetic variation reported in this study for grafted lines of C. lanatus contribute to the understanding of the underlying mechanisms of plant growth observations resulting from grafting. [ABSTRACT FROM AUTHOR]

Cucumber is a vegetable crop of economic importance in Mexico. In 2023, fresh or frozen cucumber and pickle international sales reached USD 783M, placing Mexico in second rank among countries with the highest currency inflow in the world. This crop is mostly grown under protected environments with new production technologies, including rootstocks that are tolerant to biotic and abiotic factors that limit the yield and quality of the harvest. Therefore, the goal of this work was to assess three cucurbits as rootstocks (Cucurbita maxima, Cucurbita moschata and Citrullus lanatus), as well as studying the response of cucumber crop to the tested rootstocks. The following treatments were assessed: T1:PSP = cucumber Cv. Paraizo F1 without rootstock; T2:P/MA = cucumber grafted over Cucurbita maxima; T3:P/MO = cucumber grafted over Cucurbita moschata; T4:P/CL = cucumber grafted over Citrullus lanatus Citroides Var. The assessed variables included the number of fruits per plant (NFPP), fruit weight per plant (PFPP), average fruit weight (PPF), plant dry weight (PSP), xylem vessel area (AVX), number of xylem vessels (NVX), vascular bundle area (AHV) and number of vascular bundles (NHV) in roots (R), basal stalk (TB) and apical stalk (AT). Significant differences among treatments were found in the results for variables: NFPP, highlighting that T2:P/MA was superior by 46.15% versus T1:PSP and by 67.69% versus T3:P/MO. Regarding PFPP, T2:P/MA achieved the highest weight (5445 g), as it proved superior by 99.45% than the cucumber without rootstock (T1:PSP). Regarding PSP, T2:P/MA achieved the highest weight (196.65 g), significantly exceeding T1 by 137.5%. Regarding AVXR, T4:P/CL had the highest value (30,063 µm2). Regarding NHVR, watermelon had (T4:P/CL) 39.33% more vascular bundles than the root system of cucumber (T1:PSP). Treatments T2:P/MA and T4:P/CL had the highest values at AVXTB, while for variable NVXTB, treatments T3:P/MO and T2:P/MA were almost equal, surpassing non-grafted cucumber by 175.47%. However, T2:P/MA showed the greatest AHVTB, and T1:PSP was significantly superior to T3:P/MO, by 34.93%, for NHVTB. Furthermore, positive and significant correlations were found among PFPP, AHVR, and AVXTB, as well as among PSP, AVXTB, and AHVTB. Therefore, we may say that having a larger area of vascular vessels in the roots and a larger area of xylem vessels in the basal stalk leads to higher fruit yields per plant. In the same vein, the use of rootstocks is a sustainable alternative to increase fruit yield. [ABSTRACT FROM AUTHOR]

Potassium (K) is essential for the development of grapevines (Vitis vinifera), accumulating into berries during maturation. Elevated K has been associated with high sugar and low acidity in juice. Characterising the accumulation patterns of K and other components in pericarps treated with various experimental factors may indicate potential regulators of berry K levels. A soil fertiliser trial using nutrient solutions with two K supply rates was conducted on potted Shiraz vines during berry ripening. Doubled-K supply increased L-malic acid content in the early-ripening phase, and increased K and magnesium concentrations in the late-ripening phase. Doubled-K supply reduced the ratio of K to sodium in later ripening phases, suggesting that the accumulation of K relative to sodium was limited in more mature berries supplied with extra K. Pericarp water percentage, sugar, K and ATP were correlated in both treatments, indicating links between hydration, solute transport and energy in maturing berries. In a separate rootstock trial over the two growing seasons, Shiraz scions grafted onto 420-A rootstock produced berries with lower K concentration and content than those grafted onto Ramsey or Ruggeri-140 rootstocks and own-rooted vines. This study demonstrated that the K supply and berry ripening phase impacted the berry K level. Increased potassium (K) concentration in grape (Vitis vinifera) berries is associated with loss of acidity and high sugar content in juice. This study demonstrated that the K supply to Shiraz and berry ripening phase could impact the berry attributes and chemical composition at harvest, associated with the linkages between water, sugar, K and ATP. From this study, we suggest that grape berry maturation and composition management may be beneficial. [ABSTRACT FROM AUTHOR]

Citrus is commercially propagated via grafting, which ensures trees have consistent fruit traits combined with favorable traits from the rootstock such as soil adaptability, vigor, and resistance to soil pathogens. Graft incompatibility can occur when the scion and rootstock are not able to form a permanent, healthy union. Understanding and preventing graft incompatibility is of great importance in the breeding of new fruit cultivars and in the choice of scion and rootstock by growers. The rootstock US-1283, a citrandarin generated from a cross of "Ninkat" mandarin (Citrus reticulata) and "Gotha Road" #6 trifoliate orange (Poncirus trifoliata), was released after years of field evaluation because of its superior productivity and good fruit quality on "Hamlin" sweet orange (C. sinensis) under Florida's growing conditions. Subsequently, it was observed that trees of "Bearss" lemon (C. limon) and "Valencia" sweet orange (C. sinensis) grafted onto US-1283 exhibited unhealthy growth near the graft union. The incompatibility manifested as stem grooving and necrosis underneath the bark on the rootstock side of the graft. Another citrandarin rootstock, US-812 (C. reticulata "Sunki" x P. trifoliata "Benecke"), is fully graft compatible with the same scions. Transcriptome analysis was performed on the vascular tissues above and below the graft union of US- 812 and US-1283 graft combinations with "Bearss" and "Valencia" to identify expression networks associated with incompatibility and help understand the processes and potential causes of incompatibility. Transcriptional reprogramming was stronger in the incompatible rootstock than in the grafted scions. Differentially expressed genes (DEGs) in US-1283, but not the scions, were associated with oxidative stress and plant defense, among others, similar to a pathogen-induced immune response localized to the rootstock; however, no pathogen infection was detected. Therefore, it is hypothesized that this response could have been triggered by signaling miscommunications between rootstock and scion either through (1) unknown molecules from the scion that were perceived as danger signals by the rootstock, (2) missing signals from the scion or missing receptors in the rootstock necessary for the formation of a healthy graft union, (3) the overall perception of the scion by the rootstock as non-self, or (4) a combination of the above. [ABSTRACT FROM AUTHOR]

The paper presents the possibilities of energy management of residues from the production of 'Regent' grapevines. Field tests were conducted under conditions of temperate climate in 2022 on six types of rootstocks viz: 101-14, 125 AA, 161-49, 5 BB, SO4, SORI, the control were ungrafted vines growing on their own roots. The study analysed the following crop parameters, i.e. number and mass of grapes, number and mass of berries; quality parameters of woody shoots. Technical and elemental analysis was performed, and the heat of combustion and calorific value were determined to define fuel quality parameters. In addition, emission factors of CO, CO2, SO2, NOx and ash were estimated to demonstrate the degree of impact of potential bio-residue from the combustion process. An assessment was made on the basis of stoichiometric equations of flue gas composition, as well as theoretical oxygen demand and total fuel gas volume. The study showed that cultivation on 125 AA rootstock is characterised by obtaining significantly the highest yield, shoot mass and bio-residues suitability for energy purposes. The research showed that the most effective in practical cultivation is the use of SORI and SO4 rootstocks in cultivation, which are characterised by average parameters of obtained yield, growth value and fuel. [ABSTRACT FROM AUTHOR]

This study was carried out between 2019 and 2021 to determine chestnut rootstock candidates in Efeler District of Aydın Province. Approximately 40 km² chestnut area was observed in this study. In the research area, 11 high-yielding genotypes which were observed to be unaffected by diseases and pests were identified. The seeds of the genotypes were stratificated, then the seeds that started to germinate were first planted in pots, and the resulting young plants were transferred to the trial garden. At the end of the vegetation period, characteristics related to plant development were examined in the seedlings obtained from the genotypes. The data obtained were evaluated using variance analysis and weighted rating methods, and the scores received by the genotypes were determined. As a result of the research, genotypes coded EK 3, EK 5 and EK 6 had the highest scores and were selected as rootstock candidates. [ABSTRACT FROM AUTHOR]

The rootstock 'Rootpac R' is not used for apricots. The aim of this study was to evaluate the characteristics of 'Rootpac R' in comparison to the widely used 'Myrobalan 29C' rootstock. The evaluation of the rootstocks was conducted in combination with 16 scion cultivars to assess their effects on vegetative traits and mortality. The total height of the trees on 'Rootpac R' initially surpassed the 'Myrobalan 29C' trees. By the end of the fourth year, both rootstocks showed comparable heights with 'Rootpac R' standing at 317 cm and 'Myrobalan 29C' standing at 307 cm. Both rootstocks exhibited comparable TCSA values of 5 cm2 initially; 'Rootpac R' surpassed 35% compared to 'Myrobalan 29C'. Canopy space occupancy assessments revealed that 'Rootpac R' initially demonstrated superior space utilization, occupying 8% of the designated volume compared to 4% for 'Myrobalan 29C'. By the fourth year, 'Rootpac R' exhibited a higher occupancy rate of 65% compared to 50% for 'Myrobalan 29C'. For apricot cultivars, such as 'Bergeron', 'C. óriás', 'Gönci magyarkajszi', 'Lady Cot', 'Tardif de Valance', and 'Tom Cot', 'Rootpac R' exhibited survival rates beyond the fourth season, highlighting its effectiveness for these varieties. Based on these results, 'Rootpac R' rootstock could be useful in apricot growing. [ABSTRACT FROM AUTHOR]

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Florida citrus production faces multiple challenges, including low nutrient retention, low soil organic matter (SOM) and, more importantly, the devastating impacts of citrus greening, which is a bacterial disease that impacts root growth and nutrient uptake. Growers are exploring management practices to improve SOM and hoping to enhance tree health, nutrient uptake, and yield. Despite these efforts, research of the effects of SOM on citrus root systems and nutrient absorption remains limited, particularly that defining a target SOM range for optimal production. This study investigated the influence of varying SOM levels on citrus tree root system architecture, biomass, and nutrient uptake. This experiment was conducted in a greenhouse where 1-year-old ‘US-942’ rootstocks were assigned to a completely randomized experimental design and exposed to one of six experimental treatments with differing levels of SOM as the growing media [0% (control), 1%, 2%, 3%, 5%, or >10% (100% compost)]. Each pot was considered an experimental unit and replicated six times (n = 6), for a total of 36 seedlings. The results indicated that although root biomass did not change significantly, lower SOM levels resulted in longer roots with greater surface area and volume, likely because of increased soil exploration for nitrogen. Higher SOM treatments, however, showed improved leaf nutrient content, with increased nitrogen, phosphorus, and potassium uptake. In conclusion, the results of this study indicate that 3% SOM may be ideal for citrus because it positively impacted both root system architecture and nutrient uptake, which are both of primary concern because of citrus greening. Further research is necessary to establish critical SOM thresholds and evaluate the effects under field conditions and in combination with different irrigation and fertilizer regimes.

Two field experiments were carried out in 2022 and 2023 within commercial watermelon fields in Stockton and Modesto, CA, USA. Two Trichoderma-containing products were applied to the grafted and nongrafted watermelon seedlings through tray soaking or field chemigation. All seedlings were mechanically transplanted into a split-split plot design with the Trichoderma product as the main factor and application method (tray soaking and chemigation) as the sub-plot. The sub-sub-factor included three interspecific hybrid squash rootstocks (Cucurbita maxima × Cucurbita moschata) ‘Cobalt’, ‘Flexifort’, and ‘RS841’ that were grafted with the commercial seedless watermelon scion ‘Summer Breeze’. All treatments were replicated four times. Vine health was visually assessed three times, and canopy coverage was assessed for a total of six measurements for each year. Harvest was conducted three times in 2022 and twice in 2023 to analyze yield and quality differences among treatments. Aboveground and root samples from defective plants were taken amid the harvest and shipped to the University of California, Davis Fungal Pathology Diagnostics Research Laboratory for identification of soilborne fungal pathogens to confirm or rule out their involvement in vine declines initially attributed to nonpathogenic factors. The laboratory diagnosis indicated that Macrophomina was morphologically identified from the foot and root isolations of 67% of the submitted nongrafted, non-Trichoderma-biofungicide–treated plants in 2022. Further sequencing results confirmed the primary pathogen, Macrophomina phaseolina, from 50% of those submitted plant samples. In addition, putative Fusarium root and stem rot (Fusarium oxysporum f. sp. radices-cucurmerinum) and Falciforme crown rot and decline (Fusarium noneumartii) from runners and roots of nongrafted, noninoculated plants in the 2022 experiment were also reported. However, no significant soilborne fungal pathogens were found in the 2023 experiment. In both trials, the effects of Trichoderma-containing biofungicides and their application methods on preventing vine decline, maintaining canopy coverage, and enhancing fruit yield and quality were not as remarkable as grafting. The average grafting effect contributed to 83% and 53% decrease of vine decline compared with the nongrafted plants in 2022 and 2023. Overall, grafted plants yielded 47.6% and 32.4% more than the nongrafted counterpart in 2022 and 2023, respectively. In addition, grafting exerted predominant influence on fruit firmness and rind thickness. The study results indicated that grafting onto multipathogen resistance watermelon rootstocks serves as an effective production tool to maintain fruit yield, quality, and plant health under both pathogenic and disease-free conditions. Further work is still needed to continue evaluating best practical application protocols of Trichoderma-based biofungicides and other biopesticides to enhance product effectiveness and end users’ confidence in reducing soilborne diseases and reliance on conventional fumigants.

High-tunnel systems can improve and prolong production under challenging climate, but research on nitrogen management and grafting is still needed. This study analyzes the effects of rootstock and two N fertilization levels in northern Nevada under high-tunnel commercial production. We report on tomato yield, growth, leaf nutrient profile, and spectral indices [i.e., soil plant analysis development (SPAD) and normalized difference vegetation index (NDVI)] correlation with leaf nitrogen. Although rootstock influenced yield and leaf nutrient profile depending on location, no clear effect from the nitrogen fertilization was observed in growth and yield. Moreover, the low accuracy of SPAD and NDVI indices in predicting leaf nitrogen status undermined the capacity to provide enough support for a sustainable nitrogen fertilization management.

Foot rot disease (Phytophthora capsica) is Indonesia's primary challenge in cultivating pepper (Piper nigrum). Grafting to another Piper species, Piper coclobrinum, or melada (the local name), is a potential solution to increase resistance to this disease. The use of melada as rootstock has shown promising results during the seedling phase, but it has not been thoroughly evaluated during the production phase. The study was conducted in the pepper grower’s location in Puput and Simpang Katis Villages, Central Bangka, Bangka Belitung Islands Province. The study used kapok (Ceiba petandra) as the standard; plant morphology, leaf area, leaf thickness, and crown diameter for grafted melada and non-grafted pepper were recorded. Harvest variables included panicle length, panicle weight, the number of fruits per panicle, and fruit diameter, measured in three different areas of the canopy: the lower area (0-1 meter above the ground surface), the middle area (1-2 meters above the ground surface), and the top area (more than 2 meters above the ground surface). Physiological variables measured included rates of photosynthesis, stomatal conductance, transpiration rate, intercellular CO2, and CO2 conductance. The study demonstrated that the grafted pepper plants had a larger leaf area than the non-grafted pepper plants; the panicle weight and the number of fruits per panicle were higher. Panicles located in the middle zone of the plant canopy tended to be longer for grafted and non-grafted peppers. Panicle weight, fruit size, and the number of fruits per panicle were generally more significant at the top of the plant canopy. In all parts of the canopy, grafted peppers exhibited larger fruit size, greater panicle weight, and a higher number of fruits per panicle than non-grafted “Nyelungkup” peppers, highlighting the potential of melada as a rootstock for pepper plants.

Background Root plays an important role in the growth and development of fruit trees; however, the molecular mechanisms behind the differences among rootstock varie-ties remain unclear. Methods This study examined the effects of different rootstocks on root structure and the endogenous hormone content of 1-year old apple seedlings in combinations of Tianhong 2 (T2)/Malus robusta (HT), T2/G935, and T2/Jizhen 2 (J2). Results The results showed that the T2/HT treatment had greater root length, surface area, volume, average diameter, tips and forks, followed by G935 and J2. In T2/HT leaves and roots, the indole-3-acetic acid (IAA) and gibberellins (GA3) levels were highest, and the abscisic acid (ABA) levels were the lowest. A root transcriptome analysis detected 10,064, 10,511, and 8,719 differentially expressed genes in T2/HT vs. T2/G935, T2/HT vs. T2/J2, and T2/J2 vs. T2/G935, respectively. The analysis of Gene Ontology (GO) terms indicated a significant enrichment in biological processes, cellular components, and molecular functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that plant hormone signaling, MAPK signaling pathway–plant, and plant–pathogen interaction played important roles in differences in the rooting ability of different rootstocks. In addition, some key differential genes were associated with root growth and development and were involved in these metabolic pathways. This study is important for enriching theoretical studies of fruit tree roots.

This editorial explores the use of rootstocks in crops and fruit trees as a means to address the challenges posed by climate change and abiotic stress in agriculture. By grafting plants onto tolerant rootstocks, growers can enhance crop resilience and reduce the need for resources like water and fertilizers. The selection of suitable rootstocks is a complex process that involves considering various root-related traits. The editorial also delves into the physiological and molecular aspects of tolerance to different types of abiotic stresses associated with the use of rootstocks. The document discusses the identification of significant QTLs related to tolerance to iron chlorosis in Prunus plants, with the goal of developing tools and biotechnological technologies to improve the performance of plants grafted on stress-tolerant rootstocks. The authors acknowledge the support of a research project funded by the Ministry of Science and Technology of Chile. [Extracted from the article]

IntroductionExternal and internal quality of citrus such as color, shape and taste increase economic benefit. The vigour of each rootstock causes qualitative and quantitative change and the effective factor on commercial maturity, which is important for gardeners and producers. Considering the characteristics of the fruit in grafted trees, the present research was conducted with the aim of evaluating the effects of trifoliate orange, Citrange and Citrumelo rootstocks on some morphological, phytochemical and molecular traits of ‘Thomson Navel’ orange fruit. Materials and MethodsThis research was carried out in 2018 at Ghaemshahr Horticultural Research Station, Mazandaran. It was conducted in the form of randomized complete block design (RCBD) of uniform and 10-year-old ‘Thomson Navel’ orange grafted on ‘trifoliate orange’, ‘Citrange’ and ‘Citrumelo’ rootstocks with four replications. The samples were collected at the end of October and were transferred to the research laboratory of Horticulture Department, Gorgan University of Agricultural Sciences and Natural Resources for further research. Measurements were made on the morphological traits, quality characteristics of the fruit, the phenolic compounds of the peel and the pulp of the fruit and relative expression of fruit pulp sucrose phosphate synthase1 gene. Data variance analysis was done using SAS software (version 9.0). Mean comparisons were done with Duncan's multiple range test. Results and DiscussionThe results of analysis of variance showed that the rootstock effect on traits of length-to-diameter ratio, weight and density of ‘Thomson Navel’orange was significant at the five percent probability level (p

IntroductionPear (Pyrus communis L.) is a cold-climate fruit tree belonging to the Rosaceae family, and it is native to Western Asia and Eastern Europe. Fire blight disease is caused by the gram-negative bacterium Erwinia amylovora, and it is considered one of the most damaging and harmful diseases in pome fruit trees in cold and temperate regions worldwide. The most sensitive plant organ in pome fruit trees to this disease is flowers. Fire blight disease has five important stages, from initial infection to the final death of the tree trunk. These five stages include blossom blight, fruit blight, leaf blight, main branches, and trunk blight, and finally, root blight. The first and most important stage of pathogenicity in fire blight disease begins in early spring under high humidity, causing the burning and death of the flower. Materials and MethodsThe Rootstock used in this experiment were Dargazi and Pyrodwarf, and the cultivars studied were Koshia and Dargazi. The experiment was conducted in two conditions, orchard and greenhouse. In the orchard, a factorial experiment was carried out in a completely randomized block design with five repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Koshia and Dargazi). In the greenhouse, a factorial experiment was carried out in a completely randomized design with three repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Dargazi and Kosha). Gardner scale was used to measure the severity of fire blight infection. In addition, the levels of sucrose, sorbitol, and pH in leaf tissue were measured. The sucrose content in the leaf tissue of Koshia/Pyrodwarf Rootstock increased from day 0 to 6 and reached its highest level (10%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Pyrodwarf base, sucrose levels increased from day 0 to 6 and reached its highest level (8%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Dargazi base, sucrose levels increased from day 0 to 6 and reached its highest level (7%) on the 6th day, then decreased to 4% on the 12th day. The sorbitol content in the leaf tissue of Koshia/Pyrodwarf base increased from day 0 to 6 and reached its highest level (2%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1.5%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Dargazi Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1%) on the 6th day, then decreased to 0.5% on the 12th day. On the other hand, the pH of the leaf tissue in the Dargazi/Pyrodwarf base remained constant at 6.2 from day 0 to 12 and increased to 7.4 on the 12th day. Results and DiscussionThe rootstock used in this experiment were Dargazi and Pyrodwarf, and the cultivars studied were Koshia and Dargazi. The experiment was conducted in two conditions, orchard and greenhouse. In the orchard, a factorial experiment was carried out in a completely randomized block design with five repetitions. The factors studied were rootstocks (Dargazi and Pyrodwarf) and cultivars (Koshia and Dargazi). In the greenhouse, a factorial experiment was carried out in a completely randomized design with three repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Dargazi and Koshia). Gardner scale was used to measure the severity of fire blight infection. In addition, the levels of sucrose, sorbitol, and pH in leaf tissue were measured. The sucrose content in the leaf tissue of Koshia/Pyrodwarf Rootstocks increased from day 0 to 6 and reached its highest level (10%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sucrose levels increased from day 0 to 6 and reached its highest level (8%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Dargazi Rootstock, sucrose levels increased from day 0 to 6 and reached its highest level (7%) on the 6th day, then decreased to 4% on the 12th day. The sorbitol content in the leaf tissue of Koshia/Pyrodwarf Rootstock increased from day 0 to 6 and reached its highest level (2%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1.5%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Dargazi Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1%) on the 6th day, then decreased to 0.5% on the 12th day. On the other hand, the pH of the leaf tissue in the Dargazi/Pyrodwarf Rootstock remained constant at 6.2 from day 0 to 12 and increased to 7.4 on the 12th day. The collected data from both orchard and greenhouse experiments were analyzed to determine the effects of Rootstock and cultivar on fire blight resistance. ConclusionThe results showed that the combination of Koshia/Dargaz had higher resistance to fire blight compared to Koshia/Pyrodwarf. Additionally, the pH and carbohydrate content in the leaf tissue of the rootstock affected the growth and proliferation of fire blight bacteria. This study demonstrated varying levels of resistance to fire blight among the studied combinations, indicating significant potential for breeding and improving pear resistance to this disease. The Dargazi cultivar exhibited very high resistance to fire blight in both orchard and greenhouse conditions. Overall, the resistance of the Dargazi rootstock contributed to the resistance of the sensitive Koshia cultivar.

This paper investigates the effect of rootstock (Gisela 6, PiKu 1 and SL 64) on the total phenol content, total anthocyanin content, the content of the individual phenols and the antioxidant activity in fruits of two sweet cherry cultivars, 'Kordia' and 'Regina'. The total phenolic content determined by the spectrophotometric method using Folin-Ciocalteu reagent varied from 34.84 to 149.28 to mg GAE/100 g FW depending on the cultivar/rootstock combination. The concentration of total anthocyanins was determined by using the pH-differential method and it ranged from 0.46 to 11.54 mg CGE/100 g FW. Highest level of the total phenolic content and concentration of the total anthocyanins content was detected in the cultivar 'Regina' grafted onto the Gisela 6 rootstock. Neochlorogenic acid, catechin, chlorogenic acid and quercetine-3-O-glucoside were detected using HPLC method. Significant variation of detected individual polyphenols in sweet cherry fruits grafted on different rootstocks was observed. The lowest content of individual polyphenols was measured in 'Regina' cultivar grafted on the SL 64. Ferric reducing antioxidant power assay indicated that all investigated fruits possessed similar antioxidant activity. There was a statistically significant correlation observed between the total phenolic content and antioxidant activity (correlation coefficient 0.972, P-value below 0.01), as well as between the anthocyanins and antioxidant activity (correlation coefficient 0.855, P-value below 0.01).

Relevance. Tomato (Solanum lycopersicum L.) is one of the most important vegetables in the world. Every year the number of identified viruses and diseases increases, infection with which causes significant crop losses and significantly worsens the quality of agricultural products, especially in tomatoes. Material and methods. In the present study we compared the growth of the vegetative and reproductive traits of tomato plants ‘Dokia’, ‘TY Red 250’ and ‘Pilabi’ grated onto bacterial wilt (caused by Ralstonia solanacearum) and Fusarium wilt (Fusarium oxysporum) diseases tolerant rootstock “Spider” (Takii seed, Japan). The non-grafted (control - CT) and grafted tomato plants (GR) were transplanted on 4 March of 2021 to the four season (vinyl) greenhouse on substrate perlite (mixture of perlite no. 1 and no. 3) and cultivated until September 20. Results. The results showed that responses of the tomato cultivars to grafting combination was different, where agronomical traits depends on the each cultivar’s features can be ranged. The reduction of the values of stem diameter (SD), leaf length and width (LW), fresh fruit weight (FFW), fruit diameter (FD), fruit pericarp thickness (FPT) and fruit hardness (FH) with aging of plants and rising ambient temperature was detected. However, fruit soluble solids among all cultivars regardless of treatments were slightly increased. The index of fruit yield per truss (FYT) significantly decreased among all cultivars after 10th truss regardless of the treatments when the daily temperature increased from July to August. In grafted tomato ‘TY Red 250’ were identified the highest fruit yield per plants (FYP) than in CT plants, whereas in other tomatoes did not found similar differences between CT and GR plants.

The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia) ‘PY-9’ was identified and used as the material for anatomical analysis. ‘PY-9’ grew to half the tree height of the normal cultivar ‘Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate between ‘PY-9’ and ‘Zhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar. ‘PY-9’ showed a higher photosynthetic rate than ‘Zhengdu’. Anatomical analysis showed that ‘PY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues than ‘Zhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity in ‘Zhengdu’ than in ‘PY-9’, which could contribute to the more vigorous growth of ‘Zhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.

Rootstocks serve as a strategic tool for grapevine adaptation to specific biotic and abiotic conditions and for managing vine growth, grape yield, and berry composition in commercial vineyards. This study investigates the influences of four different rootstock varieties (101-14 MGt, 3309 C, 110 R, and 140 Ru) on the viticultural performance of 'Xinomavro' vines, a prominent Greek red winegrape varietal. By conducting a two-year field experiment using various rootstocks, we assessed parameters related to water status, vegetative growth, yield, and berry composition. Our results revealed that rootstock selection has a significant impact on vine development, especially in terms of berry size and the concentrations of secondary metabolites. Principal component analysis confirmed the complex interaction between rootstock vigor and vine productivity. This study underscores the importance of rootstock variety in manipulating grapevine characteristics, particularly for the 'Xinomavro' variety, in response to regional climatic conditions. [ABSTRACT FROM AUTHOR]

The global cannabis market is continuously expanding and as a result, the cannabis industry demands new and improved agronomic cultivation practices to increase production efficiency of cannabidiol (CBD), which is valued for its therapeutic benefits. This study investigates the influence of three rootstock types on the survival rate, morphological parameters, and biochemical composition of cannabis: potentially dwarfing rootstocks (PDR), potentially vigorous rootstocks (PVR), and seedlings-as-rootstocks (SAR). Rootstocks were used for grafting two scion genotypes: 'ScionII' = chemotype II of industrial hemp, and 'ScionIII' = chemotype III of high CBD accumulating variety. Contrary to expectations, PVR and SAR did not outperform PDR on most of the measured variables. SAR showed the highest survival rate of the grafted cannabis plants (40–70%). The rootstock type had a statistically significant influence only on the bud compactness index in 'ScionII', with PDR being particularly noticeable. A comparative analysis of the 'rootstock/scion' combinations with their controls (non-grafted scions) revealed grafting's substantial improvement in most traits. Specifically, PDR increased CBD content by 27% in 'ScionIII', inflorescence yield and CBD yield per plant increased by 71% and 84%, respectively, when SAR was used in 'ScionII'. SAR showed to be the most effective rootstock type for CBD production. Our findings suggest grafting as a promising technique for optimizing cannabis's agronomic and medicinal potential, highlighting the necessity for further research on its underlying mechanisms to refine production efficiency and quality. [ABSTRACT FROM AUTHOR]

Mycorrhizae provide a permanent, reliable and natural way to reap the benefits of symbiosis. Since the susceptibility of different apricot rootstocks to mycorrhization varies considerably, tree conditions can be improved to varying degrees. To determine the degree of naturally occurring colonization (low, high and total), we tested two Hungarian scion cultivars ('Gönci magyar kajszi' and 'Ceglédi szilárd') with six rootstock cultivars from different origins. The results were obtained by microscopic analysis of dyed root samples. The rootstocks 'Apricot seedling' and 'Myrobalan 29C' are the most susceptible in our orchards. The insufficient colonization of the plum rootstocks 'Wavit' and 'Fehér besztercei' could be due to the water requirements of plum as a rootstock, which puts them at a disadvantage in non-irrigated conditions. However, no statistical differences were found between the rootstocks in the proportion of uncolonized roots, except that the roots of 'Gönci magyar kajszi' were more colonized than those of 'Ceglédi szilárd'. [ABSTRACT FROM AUTHOR]

Fertilization of cacao seedlings is not yet a widely accepted practice in the Philippines and research studies are needed to define sources, rates and timing of application. The use of fertilizer as an agricultural technique for supplying the nutrients necessary for the development of cacao seedling in the nursery is an option. The objective of this study was to determine how different doses of the fertilizer can affect the growth of cacao seedlings in terms of days of emergence, plant height, stem girth, and number of leaves. The study was conducted at Buhangin Baler in Aurora province, the Philippines from June 2022 to December 2022. The experiment used a randomized complete block design with three treatments and four replications. The treatments were: T1 – Control (No inorganic fertilizer); T2 – Recommended Rate of Inorganic Fertilizer (RRIF) based on soil analysis result; and T3 – Double the Recommended Rate of Inorganic Fertilizer based on soil analysis result. The variant T2 or Recommended Rate of Inorganic Fertilizer applied had the best response out of the three treatments in terms of plant height, and stem girth and has a high percentage of survival after grafting and fertilization. The results showed that the grafted seedlings (BR 25 cacao variety as rootstock and Criollo cacao variety as scion) responded well in terms of plant height, and stem girth and has a high number of survival rate (60-65%) after grafting and application of 25% and 50% fertilizer. In terms of number of leaves, the grafted BR 25 cacao variety as rootstock and Criollo cacao variety as scion and grafted BR 25 cacao variety as rootstock and UF 18 cacao variety as scion were best performing at both single (T2) and double (T3) rate of fertilizers applied. [ABSTRACT FROM AUTHOR]

Grapevine is one of the most economically important fruit crops cultivated worldwide. However, grapevine is highly susceptible to virus infections and exposed to the most diverse forms of viral diseases compared to other fruit crops, and virus-induced incompatibility affects plant growth to different degrees ranging from decline to death. The influence of virus-induced incompatibility could be mitigated to an acceptable level by using appropriate rootstocks. However, the viral tolerance of various grapevine rootstocks with diverse genetic backgrounds remains unclear, along with the identification of the specific viral tolerance factors. In this study, the viral tolerance of 21 grapevine rootstocks was evaluated in a green grafting system. Cabernet Franc varieties infected with a single virus [grapevine leafroll associated virus-1 (GLRaV-1)], a co-infection of two viruses (GLRaV-1 plus grapevine virus A—GVA), and no infection were used as the scions, respectively. The vegetative growth and photosynthetic function of the grafts were analyzed 4 months after grafting. The results indicated that some rootstocks could alleviate the influence of the virus infection, with vegetative growth and photosynthetic function sustained at a normal level, whereas other rootstocks were susceptible to the virus infection, resulting in a decline in the growth and photosynthetic function of the grafts. Our research provides evidence for the existence and diversity of viral tolerance among grapevine rootstocks, offering important information for appropriate rootstock selection in the establishment of new vineyards and in the breeding of grapevine rootstocks with enhanced viral tolerance. [ABSTRACT FROM AUTHOR]

Nonpoint-source phosphorus (P) from agricultural fields is a contaminant of surface waters, and high soil P fertility exacerbates this problem. Many vegetable growers and gardeners have a history of applying more P than is necessary for optimum plant growth. Avoiding unnecessary P applications is an important part of the long-term solution to reducing P loading in water. When soil P levels are very high, management practices that result in more intense P removal are recommended to reduce these levels and the potential for aquatic ecosystem contamination with P. Growers may apply soluble starter fertilizer containing P to encourage rapid transplant establishment; however, the effectiveness of this practice is unknown for soil P levels considered high or very high. Grafting tomatoes (Solanum lycopersicum L.) onto vigorous rootstocks may help the plant remove more P from the soil than nongrafted plants. This study investigated the effects of organic starter P fertilizers applied to three hybrids of nongrafted tomato and the same hybrids grafted onto ‘Estamino’ rootstock in field-grown conditions during three site-years with high preplant P fertility. The yield, fruit P concentration, and amount of P removed from the field were measured to elucidate starter P and grafting impacts on P removal. Starter P was not impactful on all responses. Grafting increased the total yield by 11.6%, fruit P concentration in a genotype-dependent manner (average of 12.6%), and net P removal from the field by 28.4% (6.0 kg P/ha). Net P removal was positively correlated with the total yield (r = 0.821) and fruit P concentration (r = 0.502), suggesting that practices to increase the yield or P concentration independently increase net P removal. [ABSTRACT FROM AUTHOR]

In this study, the effects of different rootstocks (including cultivars) on the quality and sensory properties of Shine Muscat grapes were investigated with own-rooted vines as control. Compared to the own-rooted vines, berry weight, TSS/TA and phenolic profiles were altered by the rootstocks to varying extents. The rootstocks widely altered the amounts of aroma components. Berries on 'Yuanyu' (YY), 'Bixiang Seedless' (BS), 'Couderc 3309' (3309C), 'Summer Black' (SB) and 'Queen Nina' (QN) significantly increased total aroma amount to the control berries, while 'Zaoxiaxiang' (ZX) imparted slight effects on the total aroma amount. Besides, the rootstock QN and 3309C markedly upregulated the VvLoXA, VvADH1 and VvADH2 expression levels, compared to the own-rooted grapevines, the berries observably upregulated seven genes from the MEP pathway in the grafted vines on SB and 3309C. In addition, the rootstock ZX, and 'Kober 5BB' (5BB) significantly increased the VvGT7 expression levels, the berries on YY significantly enhanced the expression of VvGT14. In summary, we found that the rootstock 3309C, QN and SB provided berries of better quality and richer aroma volatiles to SM berries, and the berries on QN (V. vinifera × V. labrusca varieties) had the largest total aroma amount and berry weight. [ABSTRACT FROM AUTHOR]

Grafting serves as a pervasive methodology in the propagation of jujube plants, yet the nuanced molecular mechanisms that dictate rootstock-scion interactions remain inadequately understood. We examined the transcriptomic landscapes of jujube heterograft combinations. Contrary to self-grafting conditions, early-stage heterografting yielded no discernible advantageous effects on scion biomass accretion. Interestingly, the rootstock's biomass was significantly impacted by the scion, varying by species. The differentially expressed genes (DEGs) across graft combinations were mainly enriched for the vegetative growth of rootstocks, secondary metabolism, and resistance improvement of scions. Weighted gene co-expression network analysis (WGCNA) identified 27 hub genes which were negatively correlated with plant growth and biomass enlargement, serving as negative regulators, while the genes, L484_001734, ATHB-15, and BPC1, were involved in positive regulation. With biomass measurements, the transcriptomic data supported that an incomplete vascular recovery during early grafting led to nutrient accumulation at the graft junction, temporarily limiting plant growth while providing development resources for callus. In summary, our work has demonstrated that the intricate biological connections between the rootstock and scion guarantee the effective jujube grafting process by elucidating the molecular processes involved in the process. [ABSTRACT FROM AUTHOR]

The use of different rootstocks has a significant effect on the content of flavor components and overall fruit quality. However, little information is available about the metabolic basis of the nutritional value of citrus plants. In this study, UPLC-MS/MS (ultra-performance liquid chromatography-tandem mass spectrometry) was performed to analyze the metabolites of three late-maturing hybrid mandarin varieties ('Gold Nugget', 'Tango' and 'Orah') grafted on four rootstocks ('Trifoliate orange', 'Carrizo citrange', 'Red tangerine' and 'Ziyang Xiangcheng'). A total of 1006 metabolites were identified through OPLS-DA (Orthogonal Partial Least Squares-Discriminant Analysis) analysis. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis revealed the most critical pathways among the different pathways associated with genes grafted on the four rootstocks that were differentially activated, including tryptophan metabolism and sphingolipid metabolism in 'Gold Nugget'; tryptophan metabolism, phenylpropanoid biosynthesis and sphingolipid metabolism in 'Tango'; and pantothenate and CoA biosynthesis- and photosynthesis-related biosynthesis in 'Orah'. A considerable difference between the different rootstocks was also observed in the accumulation of lipids, phenolic acids and flavonoids; further analysis revealed that the rootstocks regulated specific metabolites, including deacetylnomylinic acid, sudachinoid A, amoenin evodol, rutaevin, cyclo (phenylalanine-glutamic acid), cyclo (proline-phenylalanine), 2-hydroxyisocaproic acid, and 2-hydroxy-3-phenylpropanoic acid. The results of this study provide a useful foundation for further investigation of rootstock selection for late-maturation hybrid mandarin varieties. [ABSTRACT FROM AUTHOR]