Academic literature on the topic 'Rootstock/scion interaction'

Gurusamy, V., Warkentin, T. D. and Vandenberg, A. 2012. Grafting pea, faba bean, and lentil to improve pulse crop breeding. Can. J. Plant Sci. 92: 31–38. In vivo grafting experiments were conducted to determine their potential for improving pulse crop breeding techniques for pea, faba bean and lentil. Four scion×five rootstock genotype combinations were used for pea. Survival of grafted pea scions was not affected by genotype of scions or rootstocks, even for wild subspecies. Some scion-rootstock combinations resulted in reduced flowering time for scions. Total seed production of rootstock regrowth plus grafted scion was greater than for ungrafted controls or rooted cuttings. For faba bean, four scion×four rootstock combinations showed scion-rootstock interaction affected percent survival and flowering time of grafted scions. In vivo grafting of lentil scions to faba bean rootstocks is reported for the first time. Two lentil genotypes were grafted onto four faba bean rootstocks. The effects of lentil scion and faba bean rootstock genotype were significant for percent survival, but not for seed production. Percent scion survival was 85% for pea, 56% for faba bean, and 55% for lentil scions on faba bean rootstocks. In vivo grafting techniques can help to maximize the size of F2 populations for breeding and genetic studies. Intergeneric in vivo grafting of lentil onto faba bean rootstock could be useful for interspecific hybridization studies for lentil.

In viticulture, grafting is used to propagate Phylloxera-susceptible European grapevines, thereby using resistant American rootstocks. Although scion–rootstock reciprocal signaling is essential for the formation of a proper vascular union and for coordinated growth, our knowledge of graft partner interactions is very limited. In order to elucidate the scale and the content of scion–rootstock metabolic interactions, we profiled the metabolome of eleven graft combination in leaves, stems, and phloem exudate from both above and below the graft union 5–6 months after grafting. We compared the metabolome of scions vs. rootstocks of homografts vs. heterografts and investigated the reciprocal effect of the rootstock on the scion metabolome. This approach revealed that (1) grafting has a minor impact on the metabolome of grafted grapevines when tissues and genotypes were compared, (2) heterografting affects rootstocks more than scions, (3) the presence of a heterologous grafting partner increases defense-related compounds in both scion and rootstocks in shorter and longer distances from the graft, and (4) leaves were revealed as the best tissue to search for grafting-related metabolic markers. These results will provide a valuable metabolomics resource for scion–rootstock interaction studies and will facilitate future efforts on the identification of metabolic markers for important agronomic traits in grafted grapevines.

Most tree fruits are commercially grown on different root systems, hence called composite plants. The section provides the root system as the rootstock, and the atop ground portion is called the scion. The combination is selected based on different traits of scion varieties, rootstock, and prevailing edaphic situations. The dated back plant propagation technique of joining two plants (grafting/budding) that directly communicates new physiological traits to the desirable scion variety from the rootstock remains unclear. In spite of this, this propagation technique continues widely applied in the multiplication of several fruit plant species. In a grafted plant, rootstocks impacted the scion variety’s growth, yield and quality attributes, physiology, nutrient accumulation as well as biotic and abiotic stress tolerance in many ways. Modern research in plant science for next-generation sequencing providing new vital information about the molecular interactions in composite plants multiplied using grafting. Now it was confirmed that genetic exchange is occurring between rootstock and scion variety through grafting joints. In this aspect, we discuss the process and the molecular mechanism of rootstock scion interactions. This review finally explains the dynamics of rootstock–scion interactions as well as their effect on physiology in terms of production, environmental stresses, and fruit quality. The morphological, physiochemical, and molecular mechanisms have been reviewed to develop an integrated understanding of this unknowable process that questions existing genetic paradigms. The present review summarizes the reported molecular mechanism between scion and rootstock and the impact of rootstocks on the production biology of scion varieties of economically important fruit crops and identifies numerous key points to consider when conducting rootstock scion interaction experiments. Rootstocks may offer a non-transgenic approach to rapidly respond to the changing environment and expand agricultural production of perennial fruit crops where grafting is possible in order to meet the global demand for fruit, food, and demands of the future.

AbstractGrafting of fresh cuttings using drought-susceptible and low-yielding clones as scions on drought-tolerant clones as rootstocks offers the possibility of raising composite plants with improved productivity and drought tolerance. Hence, the study was aimed to widen the choice of compatible composites and to delineate the underlying factors responsible for productivity and drought tolerance in grafted plants. One year-old composite plants of TRF-1, TRF-2 and UPASI-28 cleft-grafted on the rootstocks of UPASI-2, UPASI-9, ATK-1 and TRI-2025 were field planted along with their respective controls and evaluated. The results indicated that productivity and drought tolerance of scion clones varied significantly with the rootstocks used. Significant increases in yield and yield components were noted in the following graft combinations compared with their corresponding self-rooted scion clones: TRF-1 grafted on UPASI-9 and ATK-1, TRF-2 grafted on all four rootstocks, and UPASI-28 grafted on UPASI-9, TRI-2025 and UPASI-2. The findings clearly emphasize the scion–rootstock interaction as the critical determinant of productivity in grafted plants compared with vigour, drought tolerance and yield potential of scion and rootstock clones. Further, high-yielding capacity of grafts over the ungrafted scions and rootstocks was largely dependent on the yield potential of the scion clone and the degree of scion–rootstock compatibility. Higher field survival and enhanced yield observed during the drought period in the compatible grafts demonstrated their better drought tolerance compared with their respective self-rooted scions.

The cropping potential of almond (Prunus amygdalus (L.) Batsch, syn P. dulcis (Mill.)) cultivars is determined by their adaptation to edaphoclimatic and environmental conditions. The effects of scion–rootstock interactions on vigor have a decisive impact on this cropping success. Intensively planted orchards with smaller less vigorous trees present several potential benefits for increasing orchard profitability. While several studies have examined rootstock effects on tree vigor, it is less clear how rootstocks influence more specific aspects of tree architecture. The objective of this current study was to identify which architectural traits of commercially important scion cultivars are influenced by rootstock and which of these traits can be useful as descriptors of rootstock performance in breeding evaluations. To do this, 6 almond cultivars of commercial significance were grafted onto 5 hybrid rootstocks, resulting in 30 combinations that were measured after their second year of growth. We observed that rootstock choice mainly influenced branch production, but the effects were not consistent across the different scion–rootstock combinations evaluated. This lack of consistency in response highlights the importance of the unique interaction between each rootstock and its respective scion genotype.

Tree size, cumulative yield, yield efficiency and anchorage of 6 micropropagated (MP) apple (Malus domestica Borkh.) cultivars were determined in 1991 after 5 years of production, as compared with trees on seedling (sdlg) or M 7a roots. Trees were planted in 1984, with crops harvested from 1987 through 1991. Trees were generally smallest (trunk cross-sectional area) on M 7a and were largest with 4 cultivars (`Delicious', `Jonathan', `Rome', `Spartan') when micropropagated. `Golden Delicious' (GD) was largest on sdlg. Cumulative yield was affected by a scion × rootstock interaction, with few trends in scion or rootstock effects. Mean cumulative yield was 84 kg tree-1, 71 and 58 for M 7a, MP and sdlg, respectively. Yield efficiency was also affected by a scion × rootstock interaction. In 1991, mean yield efficiency was 0.5 kg cm-2 for sdlg and MP trees, but was 1.05 for M 7a. Efficiency on M 7a was superior to other rootstocks with all scions except `GD', while sdlg and MP trees were statistically similar with all scions. All trees leaned in response to prevailing westerly winds, with trees on sdlg tending to be more upright than MP or M 7a trees.

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.

Recently, so-called “vegetative” and “generative” rootstocks have been identified by seed companies as rootstock types that have different impacts on tomato scions. In this experiment of grafted grape tomato production in an organically managed high tunnel system, we characterized the effects of vegetative and generative rootstock cultivars on tomato yield components and fruit mineral contents. Grape tomato scions ‘BHN 1022’ (determinate) and ‘Sweet Hearts’ (indeterminate) were grafted onto ‘DR0141TX’ (vegetative), ‘Estamino’ (generative), and ‘Multifort’ (noncharacterized) rootstocks with self- and nongrafted scions as controls. Experiments were conducted twice with different transplanting dates (Expt. 1: 31 Jan. vs. Expt. 2: 9 Mar.) in 2018. No rootstock by scion interaction effects on whole-season fruit yield components were observed, indicating similar responses of determinate and indeterminate grape tomato scions to all rootstocks tested. For Expt. 1, the three rootstocks increased marketable fruit number, marketable yield, and total yield by 23.3%, 37.9%, and 34.4% on average, respectively, compared with the self- and nongrafted controls, primarily due to improved productivity during the peak and late harvest periods. For Expt. 2, the rootstocks did not significantly benefit any whole-season yield components. ‘DR0141TX’ and ‘Multifort’ increased stem diameter in both experiments, whereas ‘Estamino’ only increased stem diameter in Expt. 2 relative to the nongrafted controls. Consistent increase in aboveground dry biomass of rootstock treatments at crop termination in Expt. 1 corresponded to the greater yield of rootstock-grafted plants in that experiment. All rootstocks in both experiments consistently increased fruit P, K, Ca, Zn, and Fe contents on a dry weight basis at peak harvest regardless of the tomato scion used. Despite a relatively low level of root-knot nematode infestation, plants grafted with ‘DR0141TX’ or ‘Estamino’ tended to have lower root galling index ratings than scion controls and ‘Multifort’-grafted plants, which was more evident in Expt. 1. Given the different environmental conditions during the tomato production period between the two experiments conducted in high tunnels, our findings highlight the important influence of production environment on grafted tomato performance. This study on grafted grape tomatoes in high tunnel organic production systems also demonstrated that so-called “vegetative” and “generative” rootstocks had similar impacts on tomato scion yield components and fruit mineral contents.

Grapevine rootstocks can affect the nitrogen (N) status of the grafted plant due to discrepancies in their nutrient uptake and their efficiency in the allocation of assimilates. When N becomes a limiting factor, the production of phenolic compounds in grapes is enhanced as a result of a down-regulation of the flavonoid production pathway. However, it is still not fully understood if the impact of rootstocks on fruit and wine composition is mediated by their effect on the vegetative growth and N status of the scion. The main objective of the study was to test if rootstock influence on Pinot noir berry and wine phenolic composition could be related to the N status of the scion. An investigation was carried out on Pinot noir (Vitis vinifera L.) vines grafted onto six rootstocks over three vintages (2012–2014). A micro-scale fermentation technique was used to produce wines from each field replicate. Scions grafted onto SO4, a high vigour rootstock, were characterised by a 15 % higher tannin concentration in berry seed and skin compared to those grafted onto the low vigour Riparia Gloire de Montpellier, while final tannin concentration in wines depended on the rootstock. Anthocyanin concentration was higher in berries of Pinot noir grafted onto R110 compared to 125AA, which was also reflected in the wines. A Multiple Linear Regression analysis suggested that rootstock influence on berry anthocyanins was linked to the N status of scion leaves (higher Leaf NBI_R). Understanding the interaction between the N uptake efficiency of rootstocks and scion berry/wine phenolic composition will help improve the selection of suitable rootstocks that match the desired wine profile.

Twelve seedling cocoa families were evaluated as rootstocks in Sabah, Malaysia using three commercial cocoa clones as scions. The average yield was about 3 t dry cocoa beans ha−1. Yields on pure Scavina rootstock were about 10% above average and those on pure West African Amelonado about 10% below average. However, the effects of rootstock on yield were correlated with those on vigour and there was no effect on the ratio of yield to continuing vegetative growth. Rootstock did not influence bean weight or number of beans per pod or the uniformity of the trees. There was no indication of an interaction between rootstock and scion for any of the traits that were studied. The rootstock effect is considered large enough to warrant its control in critical work, especially field experiments with budded cocoa, but development of high performance scions is a higher priority in cocoa than intensive work with rootstocks.

More than 80% of vineyards around the world use grafted plants: a scion of Vitis vinifera grafted onto a rootstock of single or interspecific hybrids of American Vitis species, resistant or partially resistant to Phylloxera (Daktulosphaira vitifoliae (Fitch, 1856)). The genetic variability of grapevine rootstocks plays a fundamental role in their adaptation to the environment (Serra et al., 2013). In the climate change scenario, predicting an increase of aridity in the near future (Dai, 2013), the more frequent and severe drought events may represent the major constrain for the future of viticulture (IPCC, 2018; Schultz, 2000). Therefore, the selection of new rootstocks able to cope with unfavourable environmental condition is a key asset, as well as a strategy to improve crop yield/vegetative growth balance on scion behaviour (Corso and Bonghi, 2014). So far, the influence of rootstock on scion physiological performance during water stress has always aroused great interest. On the contrary, the scion impact on rootstock response is still less debated. Therefore, the effect of grafting on rootstock behaviour have been investigated. Phenotypical and large-scale whole transcriptome analyses on two genotypes, a drought-susceptible (101-14) and a drought-tolerant (1103 P), own-rooted and grafted with Cabernet Sauvignon, subjected to a gradual water shortage in semi-controlled environmental conditions have been performed. The ungrafted condition affected photosynthesis and transpiration, meaning the decisive role of scion in modulation of gas exchanges and in general in plant adaptation. Molecular evidence highlighted that the scion delays the stimulus perception and rootstock reactivity to drought. Since 1985, the DiSAA research group operating at the University of Milan is carrying on a rootstock crossbreeding program which has led to the release of four genotypes: M1, M2, M3 and M4. They show from moderate to high tolerance to drought (M4 > M1 = M3 > M2). In order to characterize their performance during water stress, their physiological (gas exchanges and stem water potential) and transcriptome response (genes involved in ABA-synthesis and ABA-mediated responses to drought) under well-watered and water stress conditions were examined. The behaviour of M-rootstocks (M1, M2 and M3) was compared with that of other commercial genotypes largely used in viticulture, either tolerant (140 Ru, 41 B, 110 R, 1103 P), less tolerant (SO 4, K 5BB) and susceptible (420 A and Schwarzman). Discriminant analysis (DA) showed that when water availability starts to decrease, rootstocks firstly perceives the stress activating a transcriptome response, consequently physiological changes have been observed. It also demonstrated that the three M-rootstocks were clearly discriminated: M4 was grouped with the most tolerant genotypes while M3 with the less tolerant or susceptible ones from a physiological standpoint, confirming their different attitude to tolerate water stress. M4 has proven to be a promising rootstock due to its ability to adapt to drought conditions. Considering the constant great demand for vine planting materials, the obtainment of genetically homogeneous populations (i.e. clones) from elite individuals through micropropagation represents a rapid alternative to conventional multiplication. For this reason, an efficient high-throughput protocol for M4 in vitro propagation was set up. Its attitude to shooting, root development and callus proliferation was compared to that of other rootstocks largely used in viticulture (K5BB, 1103P, 101-14 and 3309C). Moreover, pro-embryogenic and embryogenic callus from bud explants were also produced, representing a cellular material manipulable with the genetic engineering techniques. In water scarcity condition, among the mechanisms activated by M4, the great ability to scavenge ROS, related to the increased accumulation of stilbenes and flavonoids, may be such as to give it tolerance to the stress. In particular, the higher levels of trans-resveratrol were correlated with the up-regulation of some stilbene synthase genes, mainly VvSTS16, VvSTS18, VvSTS27 and VvSTS29. The over expression of these genes was linked to a structural variation in their promoter region. To confirm that VvSTSs genes may be considered putative factors of M4 better adaptation to water stress, a genome editing protocol based on the CRISPR/Cas9 system, aimed at knock-out the genes, was performed. For testing the gRNAs functionality, a transient assay on in vitro micropropagated plantlets of M4 and 101-14 was performed. The positive results obtained by this experiment will lead to the transformation of somatic embryos and regeneration of whole-edited plants using the vectors developed.

The history of cutting deeply into the vascular tissues of one growing, strong, host plant and then inserting a part of another plant in such a way that they join together is called grafting (originally from the Greek, “graphion” referring to the sharpened end of piece to be inserted, the scion). The original cut into the host plant, the rootstock, is made into the vascular cambium of the plant (i.e., that part of the plant stem that contains the meristem, which is the plant tissue made up of undifferentiated cells where growth can take place). The piece to be grafted, the scion, is also cut to its vascular tissue. The vascular joining is called inosculation, and the process can be traced back to the early cultivation of fruit trees. Healthy, fruit- bearing crops from the stock of the scion rather than that of the rootstock are known to result. That is, the meristem adapts. The vascular cambium itself consists of cells that are already partially specialized (e.g., the “xylem” for the woody tissue that carries water and some water soluble mineral nutrients and the “phloem” for carrying carbohydrates and other similar nutrients). The plan is that the undifferentiated cells, as well as those partially differentiated, will accommodate the scion to the rootstock, and the phloem from the root-stock will learn to feed the growing scion graft. Should the graft “take,” the matured scion will, with the advent of photosynthesis (vide infra), return the favor to the rootstock. Both will profit. One story of the grafting process and the interaction between plants and the insects that feed on the plants as applied to the wine industry has been told often. A family of plant par¬asitic insects which are native to North America, the Phylloxeridae (Genus: Daktulosphaira; Species: vitifolia, Fitch, 1855, commonly called “phylloxera”) were involved. Grapevines in North America had built resistance to some members of the Phylloxeridae family and had, apparently, been able to match genetic changes in the insect with their own changes over the years.