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The positive response of grafting by tolerant rootstocks or scion-stock interactions on yield and fruit traits of tomatoes under saline conditions is attributed to several physiological and biochemical changes. In this study, we investigated some tolerance mechanisms by which grafting on wild rootstocks in tomatoes can prevent or minimize the effects of salt stress in plants under hydroponics conditions. Two tomato cultivars H2274 and Galaxy were grafted onto three S. pimpinellifolium, three S. habrochaites, S. lycopersicum L. × S. pimpinellifolium and S. lycopersicum L. × S. Habrochaites hybrid tomato genotypes. Plants were grown in hydroponic culture at two electrical conductivity (EC) levels (control at 1.5 dSm-1 and salt at 8.0 dSm-1). Salt stress led to a significant reduction in biomass growths of both grafted and nongrafted tomatoes. However, the plants that are least affected by salt stress are those grafted on wild tomato rootstocks. Leaf nutrient contents were significantly affected by rootstocks under both control and salt stress conditions. In this study, under saline conditions, plants grafted on wild rootstocks had higher N, P, K, Ca, Mg, S, Mn, Fe, Zn and B contents in leaf tissues and lower Na and Cl contents than ungrafted plants. Biochemical and physiological results revealed that S. pimpinellifolium and S. habrochaites have inherited salt tolerance from their genetic background. These wild tomato genotypes can be used as rootstocks in tomato breeding programs to develop salt-tolerant tomatoes or in grafting techniques under saline irrigation conditions. [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]

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]

Plants are able to naturally graft or inosculate their trunks, branches and roots together, this mechanism is used by humans to graft together different genotypes for a range of purposes. Grafts are considered successful if functional vascular connections between the two genotypes occur. Various techniques can evaluate xylem connections across the graft interface. However, these methods are generally unable to assess the heterogeneity and three‐dimensional (3D) structure of xylem vessel connections. Here we present the use of X‐ray micro‐computed tomography to characterize the 3D morphology of grafts of grapevine. We show that xylem vessels form between the two plants of natural root and human‐made stem grafts. The main novelty of this methodology is that we were able to visualize the 3D network of functional xylem vessels connecting the scion and rootstock in human‐made stem grafts thanks to the addition of a contrast agent to the roots and improved image analysis pipelines. In addition, we reveal the presence of extensive diagonal xylem connections between the main axial xylem vessels in 2‐year old grapevine stems. In conclusion, we present a method that has the potential to provide new insights into the structure and function of xylem vessels in large tissue samples. Summary statement: Successful grafting requires the formation of functional vascular connections between two different plants. We describe using X‐ray micro‐computed tomography to characterize the network of xylem vessels formed across the graft interface of natural root and human‐made stem grafts of grapevine. [ABSTRACT FROM AUTHOR]

The purpose of the research is to identify the effectiveness of the use of various stimulating substances on the economic and biological parameters of plants of clonal apple rootstocks in the conditions of the arid zone of the Northern Caspian Sea (Astrakhan region). The objects were apple tree clonal rootstocks, scion and rootstock combinations. In the mother plantation of vertical layering, 10 breeding forms of rootstocks selected by various scientific institutions were studied. The control was the M series rootstocks, widely used and adapted in the south of Russia: M-9 for dwarf ones, M-26 for semi-dwarf ones, MM-106 for medium-sized ones. In a vertical mother plantation, there were studied variants for leaf treatments with Etamon Bio and Aminovit (control - treatment with water). Average for 2021–2023 foliar treatments significantly contributed to the high yield of first-grade rootstocks for rootstock forms 87-7-12 – 35.4 %; ‘Ural 8’ – 18.0 %; M-26 – 15.0 %; ‘Ural 5’ – 14.0 %; rootstock ‘Malysh Budagovskogo’ – 20.3 % in the variant with Etamon Bio treatment. In the variant with Aminovit treatment, the most number of first-grade layerings were obtained from the rootstock form 87-7-12 – 36.3 %; ‘Ural 8’ – 19.5 %; ‘Malysh Budagovskogo’ – 23.0 %. Foliar feeding with Etamon Bio and Aminovit had a positive effect on the length of the root system, an increase in the diameter of the trunk and an increase in the height of the rootstocks. In the first field of the nursery, the varieties were grafted onto rootstocks of varying vigor. The drugs for study were root formation stimulants Zircon; Ribav Extra; Kornevin. As a result, in comparison with the control, the survival rate of all rootstocks treated in the Zircon root formation stimulator was 100 %.

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 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]

Background and Objectives: Acquired morphological traits of seedlings in nurseries are as influential as their originality in their performance and vigor. The evaluation of these traits, including the Dickson quality index (DQI) is considered as an efficient method for considering the vigor of various kinds of seedlings, including fruit and forest seedlings. The magnitude of this index for seedlings is a function of the amount and the distribution of dry mass, height and diameter. Therefore, it is a destructive and time-consuming method for predicting seedling quality in nurseries. Consequently, in order to rank the morphological traits that determine the quality of apricot seedlings, this project was conducted to evaluate the correlation relations between such traits of apricot seedlings of the most important commercial varieties produced in different regions of Iran, based on path analysis and multiple linear regression analysis. Materials and Methods: To evaluate the relationship between the morphological indicators in apricot seedlings, bare-root seedlings of 12 commercial cultivars with three replicates from 8 nurseries in four provinces were lifted during the transplanting seasons of 2020-2021. Seedling height, diameter above grafting line (DAGL), root length, number of roots and branches, shoot and root fresh and dry weights, height to diameter ratio, and DQI were evaluated, and simple correlations between them were estimated. The correlation coefficients were broken down into direct and indirect effects through path analysis, with DQI as the dependent variable. Results: The indices representing apricot seedling vigor, including DQI and some of its components containing DAGL, total dry mass, height to diameter ratio and shoot to root dry mass ratio were a function of the accumulated growth degree-days (AGDD) in different regions. So that by increasing AGDD from 2700 to about 4500 degree, the average DQI, DAGL and total dry mass were increased and height to diameter ratio was decreased. The shoot to root dry weight ratio of seedlings was also decreased in nurseries located in regions with more than 3400 growth degree days. Among the traits which can be evaluated at the nursery site through non-destructive methods, DAGL had a higher correlation with vigor and the other morphological traits, leading to being considered the most important index in the qualitative evaluation of apricot seedlings, followed by shoot and root dry weights. Although later can be evaluated by destructive methods, they had the highest correlations with seedling vigor. The shoot number, height, sturdiness quotient had the weakest correlations with vigor and other morphological traits. Conclusion: DAGL is considered as the most efficient index in the quality assessment of the apricot seedlings due to having the highest correlation with the DQI and other morphological traits. [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]

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]

Vegetables constitute 12% of world agricultural produce. Solanaceous and cucurbitaceous crops constitute the major share of vegetable production, but their productivity is greatly impaired by plant-parasitic nematodes, among which root-knot nematodes pose the greatest threat. Due to climate change, water scarcity, shrinking of arable land, and ill effect of pesticides, a major shift in world agriculture is taking place toward sustainability, including organic and protected farming of high-value vegetable crops year-round. Grafting offers a sustainable alternative to conventional and transgenic breeding for nematode resistance. The technique can potentially reduce the phytonematode damage relying on several factors. These include R gene-mediated plant responses, efficient cross talk of defensive genes, alteration of plant metabolism and nutrient mobility, changes in plant vigor and physiological attributes, and modification of rhizosphere microbial community. Additionally, epigenetic factors also determine the success of graft union between the scion and rootstock. Grafting should also be included as a tool in integrated nematode management practices. Studies on identifying potential rootstocks and using grafted vegetable crops to manage nematode incidence are exhaustive but scattered. Here, we review the current status of vegetable grafting for nematode management using resistant rootstocks in both open-field condition and greenhouses. This is the first review, which compiles and summarizes the information on managing nematodes using grafted vegetables. We conclude the review with futuristic research perspectives of grafting that may aid in improving vegetable productivity in a sustainable manner. [ABSTRACT FROM AUTHOR]

The selection of rootstocks is one of the first and most important stages in the establishment of grape plantations under grafted conditions, which determines the productivity of rootstock-scion combinations and the further chain of design solutions: spatial placement of rows on the land plot, accompanying the production process of agronomic and agrochemical methods. Given the high importance of terroir factors for viticulture and winemaking, we were aware of the need to consider them in detail at this design stage. The aim was to create an algorithm for selecting varieties based on local terroir factors and apply it to the design of vineyards. Based on the analysis of literary sources and the agronomic experience of viticulture and winemaking specialists, we have identified key stress factors that in general, should be taken into account when selecting varieties of rootstocks. Based on the results of a comprehensive study of terroir and analytical diagnostics of soil samples taken on a land plot located in the Bakhchisaray district of the Republic of Crimea, local stress factors representing risks were clarified and prioritized neo-medially at the site of testing the landscape-adapted approach to the selection of rootstocks: carbonate condition, risk of phylloxera infestation, high content of fine fractions in granulometric composition, short-term droughts, risk of local overwatering, phosphorus deficiency. In total 20 the most common commercial varieties of rootstocks were considered for each selected soil area. The sample reduction scenario, based on the prioritization of the above stressors, reduced the number of varieties considered to three variants: 1103 Paulsen, 140 Ruggeri, and Fercal, which were scored against each other and considering the local terroir conditions of the plot, for further comparison in terms of market and logistics in making the final design decision.

Grafting is widely used in horticulture. Shortly after grafting, callus tissues appear at the graft interface and the vascular tissues of the scion and rootstock connect. The graft interface contains a complex mix of tissues, we hypothesised that each tissue has its own metabolic response to wounding/grafting and accumulates different metabolites at different rates. We made intact and wounded cuttings and grafts of grapevine, and then measured changes in bulk flavonoid, phenolic acid and stilbenoid concentration and used metabolite imaging to study tissue‐specific responses. We show that some metabolites rapidly accumulate in specific tissues after grafting, for example, stilbene monomers accumulate in necrotic tissues surrounding mature xylem vessels. Whereas other metabolites, such as complex stilbenes, accumulate in the same tissues at later stages. We also observe that other metabolites accumulate in the newly formed callus tissue and identify genotype‐specific responses. In addition, exogenous resveratrol application did not modify grafting success rate, potentially suggesting that the accumulation of resveratrol at the graft interface is not linked to graft union formation. The increasing concentration of complex stilbenes often occurs in response to plant stresses (via unknown mechanisms), and potentially increases antioxidant activity and antifungal capacities. Summary statement: We show that after grafting stilbenes accumulate specifically in necrotic tissues, whereas other compounds accumulate in the newly formed callus tissues. This suggests that these compounds have different roles in wounding healing and graft union formation. [ABSTRACT FROM AUTHOR]

Heat stress is a major environmental constraint limiting tomato production. Tomato wild relatives Solanum pennellii and S. peruvianum are known for their drought tolerance but their heat stress responses have been less investigated, especially when used as rootstocks for grafting. This study aimed to evaluate the physiological and biochemical heat stress responses of tomato seedlings grafted onto a commercial 'Maxifort' and wild relative S. pennellii and S. peruvianum rootstocks. 'Celebrity' and 'Arkansas Traveler' tomato scion cultivars, previously characterized as heat-tolerant and heat-sensitive, respectively, were grafted onto the rootstocks or self-grafted as controls. Grafted seedlings were transplanted into 10-cm pots and placed in growth chambers set at high (38/30°C, day/night) and optimal (26/19°C) temperatures for 21 days during the vegetative stage. Under heat stress, S. peruvianum-grafted tomato seedlings had an increased leaf proline content and total non-enzymatic antioxidant capacity in both leaves and roots. Additionally, S. peruvianum-grafted plants showed more heat-tolerant responses, evidenced by their increase in multiple leaf antioxidant enzyme activities (superoxide dismutase, catalase and peroxidase) compared to self-grafted and 'Maxifort'-grafted plants. S. pennellii-grafted plants had similar or higher activities in all antioxidant enzymes than other treatments at optimal temperature conditions but significantly lower activities under heat stress conditions, an indication of heat sensitivity. Both S. pennellii and S. peruvianum-grafted plants had higher leaf chlorophyll content, chlorophyll fluorescence and net photosynthetic rate under heat stress, while their plant growth was significantly lower than self-grafted and 'Maxifort'-grafted plants possibly from graft incompatibility. Root abscisic acid (ABA) contents were higher in 'Maxifort' and S. peruvianum rootstocks, but no ABA-induced antioxidant activities were detected in either leaves or roots. In conclusion, the wild relative rootstock S. peruvianum was effective in enhancing the thermotolerance of scion tomato seedlings, showing potential as a breeding material for the introgression of heat-tolerant traits in interspecific tomato rootstocks. [ABSTRACT FROM AUTHOR]

Globally, there has been an increase in stringent regulations governing the use of chemical soil fumigants for controlling diseases, pests, and weeds. Grafting has been identified as an effective alternative to soil fumigation for managing soilborne diseases and pests in intensive vegetable cropping systems. The majority of watermelon (Citrullus lanatus) grafting research confirms that selected rootstocks play a role in improving plant resistance or tolerance to common soilborne diseases. Currently, there is a lack of evidence-based literature on the effects of grafting on watermelon fruit quality attributes and yield components. Previous reviews report wide variation in the impact of grafting on watermelon production, depending on rootstock–scion combinations and environmental conditions. This review employed evidence-based synthesis methods to comprehensively and methodically summarize research results of the impact of grafting on watermelon, with a focus on fruit quality and yield. In this systematic review, 548 citations (studies published during 2011–21) were screened against strict inclusion criteria, and data were extracted from 47 studies. Meta-analysis of percent differences between the grafted watermelon treatment and the nongrafted or self-grafted watermelon control was performed using extracted data of yield components and a wide range of fruit quality attributes. Meta-analysis of research data with variance measures was also conducted based on a rather limited number of studies. Our findings showed higher levels of total yield, average fruit weight, fruit length and width, fruit lycopene and soluble solids content, rind thickness, flesh firmness, lightness, chroma, and flesh nitrogen (N) content in grafted watermelon treatments compared with the nongrafted or self-grafted control. In particular, total yield, average fruit weight, and flesh firmness exhibited significant increases of a more than 10% difference. In contrast, grafted plants demonstrated decreases in fruit pH, hue angle, and flesh calcium content, although the reduction was not greater than 10% relative to the control. Meta-analysis of research data with variance measures further confirmed significantly greater total yield and flesh N content in grafted watermelon treatments compared with the nongrafted or self-grafted control. In addition, the meta-analysis results confirmed greater benefits of watermelon grafting in the presence of known soilborne disease pressure in contrast to the production scenarios without soilborne disease problems.

Introduction: Trans-grafting could be a strategy to transfer virus resistance from a transgenic rootstock to a wild type scion. However contradictory results have been obtained in herbaceous and woody plants. This work was intended to determine if the resistance to sharka could be transferred from transgenic plum rootstocks to wild-type apricot scions grafted onto them. Methods: To this end, we conducted grafting experiments of wild-type apricots onto plum plants transformed with a construction codifying a hairpin RNA designed to silence the PPV virus and studied if the resistance was transmitted from the rootstock to the scion. Results: Our data support that the RNA-silencing-based PPV resistance can be transmitted from PPV-resistant plum rootstocks to non-transgenic apricot scions and that its efficiency is augmented after successive growth cycles. PPV resistance conferred by the rootstocks was robust, already occurring within the same growing cycle and maintained in successive evaluation cycles. The RNA silencing mechanism reduces the relative accumulation of the virus progressively eliminating the virus from the wild type scions grafted on the transgenic resistant PPV plants. There was a preferential accumulation of the 24nt siRNAs in the scions grafted onto resistant rootstocks that was not found in the scions grafted on the susceptible rootstock. This matched with a significantly lower relative accumulation of hpRNA in the resistant rootstocks compared with the susceptible or the tolerant ones. Discussion: Using transgenic rootstocks should mitigate public concerns about transgenes dispersion and eating transgenic food and allow conferring virus resistance to recalcitrant to transformation cultivars or species. [ABSTRACT FROM AUTHOR]

This article explores the use of tomato grafts to improve yield and resistance to bacterial wilt disease. Bacterial wilt is a significant issue in tomato production, leading to reduced fruit quality and quantity. The study utilized different tomato hybrids grafted onto a wilt-resistant brinjal rootstock and found that grafting was successful, with a high success rate and field establishment. The grafted plants also demonstrated resistance to bacterial wilt. This research provides valuable insights into the potential of grafting as a solution to mitigate biotic challenges in tomato cultivation. [Extracted from the article]

Vigor control in tree crops plays an important role in increasing orchard efficiency and sustainability. It has enabled high-density plantations to maximize yield efficiency while reducing production costs. Although traditional methods such as frequent hedging and pruning are still used, dwarfing rootstocks and low-vigor cultivars are the most effective and sustainable means of vigor control, as these methods reduce labor and management costs while maintaining yield efficiency. Considerable variation among cultivars and rootstocks for vigor has been identified; however, mechanisms by which rootstocks affect scion vigor in slow-maturing tree crops remain unclear. With the lack of adequate information required for early and rapid selection, breeding programs in tree crops such as macadamia still utilize manual phenotyping, which is laborious, time-consuming, and expensive. Providing insights on emerging technologies that enhance breeding programs via rapid selection, this review summarizes the current state of vigor management and underlying mechanisms of vigor control in tree crops. It provides further understanding of the prospects of applying those techniques in rootstock and scion breeding for low-vigor and yield-efficient cultivars in tree crops, with specific reference to macadamia. [ABSTRACT FROM AUTHOR]

Gleditsia sinensis Lam. (Fam. Leguminosae; Gen.: Gleditsia) has various uses, including for medicinal, edible, chemical, and material purposes, and is widely distributed in China. However, the extent of graft compatibility and its impact on growth when using different Gleditsia species as rootstocks for grafting G. sinensis scions is not yet clear. This study examined homologous and heterologous grafting between different Gleditsia species, measuring the survival rate, morphology, photosynthesis, physiology, and hormones of the grafted plants. The results showed that G. sinensis and other Gleditsia seedlings have survival rates of over 86%. The more distant the genetic relationship between species, the lower the grafting survival rate. The grafting of fast-growing G. fera as a rootstock increased the accumulation of photosynthetic products in the grafted plants, while the grafting of slow-growing G. microphylla as a rootstock slowed down the growth rate of the longitudinal extension of the leaves of the grafted plants. Heterografted rootstocks increased the contents of IPA, PP333, ACC, and DZ but decreased the levels of GA4, iP, and SA hormones. Some hormone levels that can be highly expressed in seedlings were used as rootstocks, and the corresponding hormone levels in the grafted seedlings were still highly expressed. This study lays a material and theoretical basis for the development of new resources for the breeding and rootstock selection of G. sinensis. [ABSTRACT FROM AUTHOR]

The limited scion-rootstock combinations used in sweet orange orchards in Brazil reduce the commercial potential of citrus and lead to greater susceptibility to pests and diseases. Aiming to provide germplasm diversification, the research evaluated the Folha Murcha (FM) and Charmute de Brotas (CB) orange trees grafted onto 'Rangpur' lime (RL) and 'Swingle' citrumelo (SC) rootstocks. The study was conducted in the southern center of the state of São Paulo, in the subtropical region of southeastern Brazil. The grafted trees were planted in September 2016. The field experiment was conducted over two seasons. The combinations were evaluated based on the duration in days and degree-days of the phenological intervals, growth and yield performance, alternate bearing, fruit ripening, and quality. The trees of the two scion cultivars grafted onto RL had the shortest crop cycle, the earliest fruit ripening, and the largest canopy volume. SC produced fewer alternate bearings with greater production efficiency. The CB/SC combination produced fruits with a better color index, higher total soluble solids content, and a higher technological index. This assessment can be useful in planning orchards for dual-purpose markets, such as table fruit and the juice industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Grafting is widely used in horticulture and rootstocks are known to modify scion growth and adaptation to soil conditions. However, the role of scion genotype in regulating rootstock development and functioning has remained largely unexplored. In this study, reciprocal grafts of two grapevine genotypes were produced as well as the corresponding homo-graft controls. These plants were subjected to a low phosphate (LP) treatment and transcriptome profiling by RNA sequencing was done on root samples collected 27 h after the onset of the LP treatment. RESULTS: A set of transcripts responsive to the LP treatment in all scion/rootstock combinations was identified. Gene expression patterns associated with genetic variation in response to LP were identified by comparing the response of the two homo-grafts. In addition, the scion was shown to modify root transcriptome responses to LP in a rootstock dependent manner. A weighted gene co-expression network analysis identified modules of correlated genes; the analysis of the association of these modules with the phosphate treatment, and the scion and rootstock genotype identified potential hub genes. CONCLUSIONS: This study provides insights into the response of grafted grapevine to phosphate supply and identifies potential shoot-to-root signals that could vary between different grapevine genotypes.

US pear production is constrained by the lack of dwarfing and precocious rootstocks that revolutionized other fruit crops, such as apple. While quince is used as a rootstock in global pear production, concerns about potential graft incompatibility and lack of cold hardiness limit its adoption in the US. This work was aimed at identifying genetic determinants of dwarfing in Pyrus backgrounds to inform future breeding for dwarfing Pyrus rootstocks. In 2018, 145 rootstock seedlings of two reciprocal crosses were budded with a standard scion variety. Rootstock seedlings were also genotyped with the 70 K Pyrus SNP array. Based on two-year orchard architectural phenotypes, quantitative trait loci (QTLs) were consistently mapped on both chromosomes 5 and 15 for dwarfing traits, namely scion trunk cross-sectional area (TCA), total scion annual growth, and central leader annual growth. QTLs for rootstock TCA were also detected on both chromosomes 5 and 15; however, the chromosome 15 QTL did not co-localize with the scion trait locus. Each dwarfing haplotype accounted for 30% to 50% reduction in vigor (p < 0.05). Combined haplotype analysis showed that one dwarfing locus was sufficient to significantly reduce vigor. Presence of two dwarfing haplotypes further reduced vigor by a total of 50% to 70% (p < 0.05), but their combinatory effects were not purely additive due to epistasis. Discovery of these novel dwarfing loci (named P×Dwg1 and P×Dwg2) in Pyrus facilitates future DNA test development to enable informed parental and seedling selection for dwarfing potential.

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Copyright of Journal of Erciyes Agriculture & Animal Science is the property of Erciyes Tarim ve Hayvan Bilimleri Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Choosing the most compatible and desirable rootstock for Kalamata olive cultivar is an important decision due to the longevity of the orchard and the difficulty rooting of Kalamata cuttings. Therefore, the goal of this study was to examine the morphological, physio-biochemical, and nutritional status as ppotential markers for grafting compatibility between Kalamata olive cultivar and three olive rootstocks (Coratina, Picual, Manzanillo) during two seasons (2020–2021) as well as follow up physio-bichemical and nutritional status of one-year-old Kalamata plants (2022). Results: The results indicated that, Picual rootstock recorded the highest significant grafting success which was associated with increasing number of leaves, leaf area and SPAD value in Kalamata scions by 22.15%, 36.86% and 14.64% compared to Manzanillo rootstock as mean of both seasons, respectively. While, Manzanillo rootstock recorded the highest significant activity for peroxidase and catalase by 51.41% and 60.1% at grafting union compared to Picual rootstock. Moreover, Picual rootstock for Kalamata scions had the highest acid invertase and sucrose synthase activities by 67.23% and 57.94% compared to Manzanillo rootstock. Furthermore, Picual rootstock recorded the highest significant Gibberellic acid by 52.8% and 18.6% compared to Coratina and Manzanillo rootstocks. Meanwhile, Picual rootstock recorded the lowest significant Abscisic acid by 68.17% and 63.15% as well as the lowest total phenols by 14.36% and 23.47% compared to Coratina and Manzanillo rootstocks. Conclusions: This study sheds light for the importance of choosing the suitable rootstock for Kalamata cultivar. Also, sucrose synthase and acid invertase may have a novel role in determining grafting compatibility in olives. Increasing growth promoters (Gibberellic, Nitrogen) and decreasing both growth inhibitors (Abscisic, phenols) and oxidative enzyme (catalase, peroxidase) required for better graft compatibility. [ABSTRACT FROM AUTHOR]

Simple Summary: Microorganisms are tightly associated with crops and can be pathogens or beneficials. Rose is the main ornamental crop worldwide. During production, rose varieties (over 100 in a single farm) are permanently grafted in a unique genotype as rootstock to improve plant performance. This work aimed to study the effect of grafting on root-associated microorganisms using next-generation DNA sequencing analysis. To this end, we have demonstrated that root-associated microorganisms of the rootstock (bacteria and fungi) will depend on the grafted genotype. In other words, a change in the variety will drive unique changes in the assembly of microorganisms at the root. This manuscript discusses differences in the bacterial and fungal communities when grafted and non-grafted and their potential impact on plant performance and agriculture. The root microbiome is vital in plant development and health and is highly influenced by crop cultural practices. Rose (Rosa sp.) is the most popular cut flower worldwide. Grafting in rose production is a standard practice to increase yield, improve flower quality, or reduce root-associated pests and diseases. 'Natal Brier' is a standard rootstock used in most commercial operations in Ecuador and Colombia, leading countries in producing and exporting ornamentals. It is known that the rose scion genotype affects root biomass and the root exudate profile of grafted plants. However, little is known about the influence of the rose scion genotype on the rhizosphere microbiome. We examined the influence of grafting and scion genotype on the rhizosphere microbiome of the rootstock 'Natal Brier'. The microbiomes of the non-grafted rootstock and the rootstock grafted with two red rose cultivars were assessed using 16S rRNA and ITS sequencing. Grafting changed microbial community structure and function. Further, analysis of grafted plant samples revealed that the scion genotype highly influences the rootstock microbiome. Under the presented experimental conditions, the rootstock 'Natal Brier' core microbiome consisted of 16 bacterial and 40 fungal taxa. Our results highlight that the scion genotype influences root microbe's recruitment, which might also influence the functionality of assembled microbiomes. [ABSTRACT FROM AUTHOR]

IntroductionTrans-grafting could be a strategy to transfer virus resistance from a transgenic rootstock to a wild type scion. However contradictory results have been obtained in herbaceous and woody plants. This work was intended to determine if the resistance to sharka could be transferred from transgenic plum rootstocks to wild-type apricot scions grafted onto them.MethodsTo this end, we conducted grafting experiments of wild- type apricots onto plum plants transformed with a construction codifying a hairpin RNA designed to silence the PPV virus and studied if the resistance was transmitted from the rootstock to the scion.ResultsOur data support that the RNA-silencing-based PPV resistance can be transmitted from PPV-resistant plum rootstocks to non-transgenic apricot scions and that its efficiency is augmented after successive growth cycles. PPV resistance conferred by the rootstocks was robust, already occurring within the same growing cycle and maintained in successive evaluation cycles. The RNA silencing mechanism reduces the relative accumulation of the virus progressively eliminating the virus from the wild type scions grafted on the transgenic resistant PPV plants. There was a preferential accumulation of the 24nt siRNAs in the scions grafted onto resistant rootstocks that was not found in the scions grafted on the susceptible rootstock. This matched with a significantly lower relative accumulation of hpRNA in the resistant rootstocks compared with the susceptible or the tolerant ones.DiscussionUsing transgenic rootstocks should mitigate public concerns about transgenes dispersion and eating transgenic food and allow conferring virus resistance to recalcitrant to transformation cultivars or species.

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.

Grafting is a traditional horticultural technique that makes use of plant wound healing mechanisms to join two different genotypes together to form one plant. In many agricultural systems, grafting with rootstocks controls the vigour of the scion and/or provides tolerance to deleterious soil conditions such as the presence of soil pests or pathogens or limited or excessive water or mineral nutrient supply. Much of our knowledge about the limits to grafting different genotypes together comes from empirical knowledge of horticulturalists. Until recently, researchers believed that grafting monocotyledonous plants was impossible, because they lack a vascular cambium, and that graft compatibility between different scion/rootstock combinations was restricted to closely related genotypes. Recent studies have overturned these ideas and open up the possibility of new research directions and applications for grafting in agriculture. The objective of this review is to describe and assess these recent advances in the field of grafting and, in particular, the molecular mechanisms underlining graft union formation and graft compatibility between different genotypes. The challenges of characterizing the different stages of graft union formation and phenotyping graft compatibility are examined. [ABSTRACT FROM AUTHOR]

In this study, an experiment was conducted to suggest optimal daytime temperature and light intensity for cucumber scion and rootstock production in a plant factory with artificial light. Plant growth of cucumber scions and rootstocks at a day/night temperature of 26/18 °C and photosynthetic photon fluxes of 50, 120, 190, 260, 330, and 400 μmol·m−2·s−1 was investigated. Plant growth under daytime temperatures of 25/18, 26/18, 27/18, and 28/18 °C at a photosynthetic photon flux of 260 μmol·m−2·s−1 was investigated. As the photosynthetic photon flux increased, hypocotyl length was shortened in cucumber scions and rootstocks, but Dickson quality index, compactness, and Seedling Health Index were improved. As the daytime temperature increased, the hypocotyl length of cucumber scions increased, but the quality of seedlings decreased. The root growth of scions decreased as the daytime temperature increased. As for the correlation between the major growth indicators, Dickson quality index, compactness, and Seedling Health Index showed a high correlation of more than 0.8 in stem diameter, leaf, and root weight. Therefore, it is judged that it is most efficient to maintain the photosynthetic photon flux at 260 μmol·m−2·s−1 throughout the year and adjust the daytime temperature to 25 to 28 °C according to the season for farms and commercial nurseries that produce cucumber seedlings by installing plant factories with artificial light. [ABSTRACT FROM AUTHOR]

In Uzbekistan, there is a demand of the population for fresh melon fruits during the off-season. In the Research Institute of Vegetable, Melon Crops and Potato for the first time studies were carried out, when grown in a greenhouse, on the vegetative grafting of melon’s Zarkhal variety on the vegetable marrow varieties used as rootstocks. The aim of the research was to study the effect of vegetable marrow rootstocks on the variability of economically valuable traits of the Zarkhal melon variety and to identify promising combinations of vegetable marrow rootstocks that increase the yield and quality of melon fruits.Methods. The studies were carried out in accordance with the guidelines of the World Vegetable Center. As a control, ungrafted plants of the Zarkhal melon variety were used. For comparison with the control, plants of this variety were grafted onto their own plants. Also, plants of the melon variety Zarkhal (scion) were grafted in combinations on 10 varieties of vegetable marrow, which served as rootstocks. Vegetative grafting of melon on vegetable marrow rootstocks was carried out “in a split” in the phase of the first true leaf when the stem diameter reached 4.1–4.3 mm and plant height 4.4–5.9 cm.Results. In comparison with the control, in combinations of grafting the Zarkhal melon variety onto the Grecheskiye 110, Unumdor, Delicates and Skvorushka varieties of vegetable marrow, the flowering of paternal and female flowers, the onset of fruit formation was observed 2 days earlier. In the same combinations, fruit ripening was observed on 81-82 days, which is 4-5 days earlier than the control (86 days). They also had the tallest plants (203-205 cm), the plants formed 2-4 leaves more than the others. Marketable yields between combinations ranged from 7.89 to 9.75 kg/m2 . The melon variety Zarkhal, grafted onto its own plants, lagged behind the control in all phases of development and yield. The early yield in combinations was from 3.95 to 5.75 kg/m2 and amounted to 53-59% of the yield. The average fruit weight varied from 785 to 810 g.

To explore the quality rootstocks which impart better quality fruits in mango varieties, we studied the interactive effect of the scion and rootstock using five mango varieties (Mallika, Amrapali, Dashehari, Pusa Arunima, and Pusa Surya) grafted on three rootstocks (Olour, Kurukkan, and K-5). A total of 25 physico-chemical parameters were studied in the five grafted varieties viz., fruit weight, yield efficiency, fruit per plant, pulp percent, total soluble solids (TSS), acidity, physiological loss in weight (PLW), peel thickness, respiration rate, etc., and were found to be altered through scion–rootstock interaction. Among the five mango varieties, Olour rootstock proved best to improve the fruit quality and shelf life using the grafting approach. Physico-chemical-traits-based clustering was unable to precisely group scion varieties according to their grafting rootstock. A total of 35 shelf-life specific markers were designed from ripening genes, such as expansin, polygalactouranase, ethylene insensitive, ethylene sensitive, etc. Of these specific primers, 24 showed polymorphism among the studied genotypes. The gene diversity (GD), allele per locus (An), polymorphism information content (PIC), and major allele frequency (MAF) observed were 0.43, 2.00, 0.34, and 0.63, respectively. Cluster analysis clearly showed that scion grafted on Kurukkan and Olour rootstock, and scion varieties grafted on K-5 rootstock grouped together have more similarity. A total of eight simple sequence repeats loci (SSRs) markers were associated with eight physiological traits. Strong association of SSR loci NMSLC-12 and NMSLC-14 with yield efficiency and fruit weight were observed with a phenotypic variance of 85% and 70%, respectively. [ABSTRACT FROM AUTHOR]

Fruits are widely regarded as protective food necessary for maintaining human health. Though growing fruit crops is a highly remunerative enterprise, their cultivation faces many challenges like fluctuations in climatic factors, irregular bearing, pests and diseases etc. This causes instability in production and productivity with low economic returns from per unit area. Alternate bearer fruit cultivars are one of the serious economic problems to the fruit growers. Physiological factors like carbohydrate reserves, nutrient metabolism and phytohormones are known to be involved in flowering thereby regulating bearing habit. Draining out of carbohydrate and nitrogen reserves during ‘On’ year is known to lead to a lean crop in the ‘Off’ year as they are important for fruit bud initiation i.e., high C/N ratio helps for fruit bud initiation. The developing fruit provides a strong sink for photo assimilates. It was therefore, thought that depletion of photo assimilates, especially carbohydrates from the bud which prevents flowering induction, a hypothesis known as the nutritional theory. Knowledge about impact of carbohydrates and nutrients along with other important factors influencing flowering process is helpful in understanding the phenomena of bearing in fruit crops. [ABSTRACT FROM AUTHOR]

Long juvenile period, hard shelled nature of fruit of seed propagated plants, difficulty in grafting and poor success rate has been the major concerns in walnut production in the world. Our study will aid in standardization of suitable techniques for multiplication of high yielding varieties so as to escalate the competitiveness in the international market. Hence, this study was rendered to determine the impact of scion cultivar as well as grafting time in walnut in Jumla district, Nepal in 2021. Hartley and Payne cultivars of walnut together with four disparate grafting dates viz. 14th March, 21st March, 28th March, and 4th April were employed as treatments and the entire analysis was set down in two factorial randomized complete block design (RCBD). Twenty grafted plants were defined per treatment for the investigation and each treatment were replicated four times. Circumference of ingrafted portion (cm), scion diameter (cm), length of scion (cm), number of leaves per shoot, days to bud burst, grafting success (%), and marketable plants (%) were the parameters measured during the experiment. Our experiment unveiled highly significant influence of cultivar and grafting time on length of scion, number of leaves, days to bud burst, grafting success and marketable plants. Highest scion length (66.03cm) was recorded on ‘Payne’ while maximum number of leaves (39.75) were observed on 4th of April and least (32.25) was observed on 14th March. Significantly earlier bud burst occurred in ‘Payne’ (55.87 days) whereas ‘Hartley’ took 61.59 days to bud burst. ‘Hartley’ variety divulged maximum graft take (81.56%) and marketable plants (75%) whereas least graft take (70.31%) and marketable plants (64.38%) was found in ‘Payne’ variety. Similarly, highest grafting success (83.13%) and marketable plants (77.50%) were recorded on 4th April while least graft take (71.25%) and marketable plants (65.63%) were recorded on 21st March. In a nutshell, ‘Hartley’ variety uncloaked higher grafting success rate with 4th April as an ideal grafting time in Jumla district. Thus, grafting on the first week of April using ‘Hartley’ variety is suggested to the walnut growers and other concerned stakeholders of similar agroclimatic conditions to optimize the graft take rate.

Camellia oleifera is one of the essential wood oil trees in the world. C.oleifera was propagated by nurse seedling grafting. Since the scion of C.oleifera had a significant regulated effect on the properties of rootstock after grafting and impacted on the growth of the grafted seedlings, it was necessary to understand the characteristics of buds among varieties to cultivate high-quality grafted seedlings. The metabolome was thought to be a powerful tool for understanding connecting phenotype-genotype interactions, which has an important impact on plant growth and development. In this study, UPLC-MS was used to determine the metabolites of the apical buds of CL3, CL4, CL40, and CL53 spring shoots after 30 days of sprout and to measure the growth characteristics of roots and stems after grafting. Metabolomics analysis revealed 554 kinds of metabolites were significant differences among four varieties, and 29 metabolic pathways were identified to have significant changes (p< 0.05), including carboxylic acids and derivatives, fatty Acyls, organooxygen compounds, and prenol lipids metabolites. The metabolites appeared in all varieties, including phenethyl rutinoside in glycosyl compounds and hovenidulcioside A1 in terpene glycosides. Metabolite–metabolite correlations in varieties revealed more complex patterns in relation to bud and enabled the recognition of key metabolites (e.g., Glutamate, (±)Catechin, GA52, ABA, and cs-Zeatin) affecting grafting and growth ability. Each variety has a unique metabolite type and correlation network relationship. Differentiated metabolites showed different growth trends for development after grafting. Many metabolites regulate the growth of scions in buds before grafting, which plays a crucial role in the growth of seedlings after grafting. It not only regulates the growth of roots but also affects the development of this stem. Finally, those results were associated with the genetic background of each cultivar, showing that metabolites could be potentially used as indicators for the genetic background, indicating that metabolites could potentially be used as indicators for seedling growth characteristics. Together, this study will enrich the theoretical basis of seedling growth and lay a foundation for further research on the molecular regulation mechanism interaction between rootstock and scion, rootstock growth, and the development of grafted seedlings after grafting.

Drought, one of the most severe and complex abiotic stresses, is increasingly occurring due to global climate change and adversely affects plant growth and yield. Grafting is a proven and effective tool to enhance plant drought resistance ability by regulating their physiological and molecular processes. In this review, we have summarized the current understanding, mechanisms, and perspectives of the drought stress resistance of grafted plants. Plants resist drought through adaptive changes in their root, stem, and leaf morphology and structure, stomatal closure modulation to reduce transpiration, activating osmoregulation, enhancing antioxidant systems, and regulating phytohormones and gene expression changes. Additionally, the mRNAs, miRNAs and peptides crossing the grafted healing sites also confer drought resistance. However, the interaction between phytohormones, establishment of the scion-rootstock communication through genetic materials to enhance drought resistance is becoming a hot research topic. Therefore, our review provides not only physiological evidences for selecting drought-resistant rootstocks or scions, but also a clear understanding of the potential molecular effects to enhance drought resistance using grafted plants. [ABSTRACT FROM AUTHOR]

Citrus is among the plant germplasm conserved at the CSIR - Plant Genetic Resources Research Institute (CSIR - PGRRI), Bunso in Ghana; however, due to lack of information on the specific traits of this germplasm at the Institute, the potential diversity within the collection is not yet fully exploited. The objective of this study was to evaluate the morphological diversity among the citrus accessions under conservation at the field genebank of the CSIR - PGRRI, Bunso, Eastern region of Ghana. The various accessions were raised on rough lemon rootstocks, planted using the augmented design. The citrus accessions evaluated include different citrus types suitable for different purposes, such as Flying Dragon for rootstock, Sweet Lime for medicine and Mediterranean Sweet for fruit drink. Late Valencia and Mediterranean Sweet were used as checks. Planting was done at 8 m by 8 m. Apart from watering immediately after planting, the plants grew under natural condition without irrigation. Variability was revealed by all the traits studied, including scion trunk surface, tree shape, tree growth habit and branch angle, based on IPGRI descriptors for citrus. The resulting phylogenic tree clustered the citrus accessions mainly based on known genetic relationships, using the clustering away of citrons from mandarins as an example. Although the morphological traits used in the characterisation were not sophisticated, they were useful in discriminating among the accessions. Based on this study, the citrus genebank at CSIR - PGRRI, Bunso, Eastern region of Ghana contains 44 morphologically distinct accessions. The information generated in this study is important for guiding conservation and utilisation decisions geared towards the improvement of the citrus sub-sector in the country. [ABSTRACT FROM AUTHOR]

Demand for citrus (Citrus spp) plants for commercial orchards has increased worldwide due to the need for new plantations, renewal of disease-effected crops, and strict regulation for plant production. To evaluate faster and low-cost propagation alternatives for citrus, "Valencia" orange plants were propagated by using two minigrafting techniques (Cleft and inverted T-budding). Rootstocks were raised from "Cleopatra" mandarin seeds, and scions and buds were isolated from 1-year-old grafted plants. For cleft minigrafts, scions were inserted at 5-7 cm height inside of the decapitated rootstocks and covered with Eppendorf® tubes. For T-budding, buds were inserted at 5-7 cm height under the rootstock cortex cut. Unions were fixed with Parafilm®. Grafted plants were maintained under a shade house (50%) with two daily fog irrigation (2 min each). Treatments were distributed with a completely randomized design. Six weeks after grafting, the percentage of success, the shoot length, and the number of leaves per treatment were registered and analyzed with a T test (α=0.05). Cleft minigraft resulted in a higher success percentage and plants with larger shoots. Cleft minigraft could be considered an alternative for citrus propagation in small and medium size nurseries. [ABSTRACT FROM AUTHOR]

Plant grafting is a maneuver humans learned from nature and has been practiced since ancient times. The technique has long been applied for efficient propagation as well as for the modification of the traits of interest, such as stress tolerance, tree size, and fruit quality. Since grafting can enhance the environmental tolerance and disease resistance of a plant, its techniques are now used not only in tree species but also among vegetables. Despite such wide advantages of grafting, however, the potential cause behind a compatible graft establishment (scion-rootstock connection) is yet to be fully understood. As compared to succulent herbaceous plants, woody plants often take a longer time for the graft-take and the plants may exhibit incompatible/unsuccessful graft-establishment symptoms within a period ranging from months to years. In this review, we discuss factors involved in a successful/compatible graft establishment along with bottlenecks of our understanding and future perspectives in a simplified manner- particularly focusing on incompatible graft formation on fruit trees based on earlier studies in the field. [ABSTRACT FROM AUTHOR]

Effect of rootstock on yield and quality of cucumber scion was studied at Department of Vegetable Science, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during February-May, 2021. Parthenocarpic and non-parthenocarpic cucumber scions were grafted onto five different cultivated cucurbit species i.e. pumpkin, bottle gourd, oriental pickling melon, culinary melon and ash gourd. Significant variations were observed for all the traits under this study. The highest vine length (4.37 m) was observed in Heera scion grafted onto Lagenaria siceraria rootstock followed by Heera scion grafted onto Cucurbita moschata rootstock (4.13 m). The diameter of rootstock hypocotyl was higher in case of KPCH-1 grafted onto bottle gourd (1.48 mm) and Heera grafted onto bottle gourd (1.43 mm). KPCH-1 grafted on bottle gourd (29.33 days) and culinary melon (31 days) rootstocks showed early female flower initiation. The greater number of fruits was observed in graft combination of KPCH- 1 and bottle gourd (32) followed by parthenocarpic grafts with pumpkin (30.33) and ash gourd (30.33) rootstocks. A greater fruit weight was observed in graft combination of Heera and bottle gourd (7.51 kg) followed by Heera grafted onto pumpkin (7.38 kg). Results of this experiment suggest that these graft combinations can be employed in sustainable vegetable cultivation.

Vascular streak dieback (VSD) disease, caused by Ceratobasidium theobromae, is one of the cocoa diseases responsible for decreasing cocoa production and declining cocoa plantation area in Indonesia. Planting cocoa clones with partial resistance to VSD has been useful in managing the disease. These have been produced by grafting or budding selected resistant genotype of cocoa onto unselected seedlings. The main objective of this study was to evaluate the effect of rootstock × scion combinations on VSD resistance through top grafting. The experiment used five rootstocks and scions selected from five clones, namely: MCC-01, Sulawesi 1 (S-1), M-05, RB, BB-01 and the disease evaluation was carried out under natural infection conditions for 18 months. The experimental area was surrounded by cocoa trees from a severely VSD-infested cocoa farm. M-05 performed well for suppression of VSD incidence and severity as a scion regardless of the genotype of the rootstocks followed by Sulawesi 1 (S-1). The rootstocks M-05 and S-1 did not significantly reduce VSD incidence or severity on the susceptible scions from different clones such as MCC-01, RB and BB-01. MCC-01 showed a higher incidence and severity of VSD as a scion regardless of the rootstock genotype. This research proves that rootstocks from cocoa genotypes considered resistant, moderately susceptible, or susceptible to VSD, have little effect on cocoa scion resistance to VSD. Cocoa scion genotypes play a crucial role in VSD resistance.