Rhizome Root Research Articles

Vineyard management systems influence arbuscular mycorrhizal fungi recruitment by grapevine rootstocks in New Zealand.

Arbuscular mycorrhizal fungi (AMF) can perform significant functions within sustainable agricultural ecosystems, including vineyards. Increased AMF diversity can be beneficial in promoting plant growth and increasing resilience to environmental changes. To effectively utilize AMF communities and their benefits in vineyard ecosystems, a better understanding of how management systems influence AMF community composition is needed. Moreover, it is unknown whether AMF communities in organically managed vineyards are distinct from those in conventionally managed vineyards. In this study, vineyards were surveyed across the Marlborough region, New Zealand to identify the AMF communities colonizing the roots of different rootstocks grafted with Sauvignon Blanc and Pinot Noir in both conventional and organic systems. The AMF communities were identified based on spores isolated from trap cultures established with the collected grapevine roots, and by next-generation sequencing technologies (Illumina MiSeq). The identified AMF species/genera belonged to Glomeraceae, Entrophosporaceae, and Diversisporaceae. The results revealed a significant difference in AMF community composition between rootstocks and in their interaction with management systems. These outcomes indicated that vineyard management systems influence AMF recruitment by rootstocks and some rootstocks may therefore be more suited to organic systems due to the AMF communities they support. This could provide an increased benefit to organic systems by supporting higher biodiversity.

A Transcriptomic Analysis of Bottle Gourd-Type Rootstock Roots Identifies Novel Transcription Factors Responsive to Low Root Zone Temperature Stress.

The bottle gourd [Lagenaria siceraria (Molina) Standl.] is often utilized as a rootstock for watermelon grafting. This practice effectively mitigates the challenges associated with continuous cropping obstacles in watermelon cultivation. The lower ground temperature has a direct impact on the rootstocks' root development and nutrient absorption, ultimately leading to slower growth and even the onset of yellowing. However, the mechanisms underlying the bottle gourd's regulation of root growth in response to low root zone temperature (LRT) remain elusive. Understanding the dynamic response of bottle gourd roots to LRT stress is crucial for advancing research regarding its tolerance to low temperatures. In this study, we compared the physiological traits of bottle gourd roots under control and LRT treatments; root sample transcriptomic profiles were monitored after 0 h, 48 h and 72 h of LRT treatment. LRT stress increased the malondialdehyde (MDA) content, relative electrolyte permeability and reactive oxygen species (ROS) levels, especially H2O2 and O2-. Concurrently, LRT treatment enhanced the activities of antioxidant enzymes like superoxide dismutase (SOD) and peroxidase (POD). RNA-Seq analysis revealed the presence of 2507 and 1326 differentially expressed genes (DEGs) after 48 h and 72 h of LRT treatment, respectively. Notably, 174 and 271 transcription factors (TFs) were identified as DEGs compared to the 0 h control. We utilized quantitative real-time polymerase chain reaction (qRT-PCR) to confirm the expression patterns of DEGs belonging to the WRKY, NAC, bHLH, AP2/ERF and MYB families. Collectively, our study provides a robust foundation for the functional characterization of LRT-responsive TFs in bottle gourd roots. Furthermore, these insights may contribute to the enhancement in cold tolerance in bottle gourd-type rootstocks, thereby advancing molecular breeding efforts.

Effects of different rootstocks grafting on selenium accumulation in Cyphomandra betacea Sendt. seedlings under selenium-contaminated soil

The effects of rootstocks tomato (Solanum lycopersicum L.), eggplant (Solanum melongena L.), and nightshade (Solanum nigrum L.) grafting on the growth and selenium (Se) accumulation of Cyphomandra betacea Sendt. seedlings were studied to identify the most suitable rootstock for increasing Se uptake of fruit trees grown in Se-contaminated soil. The rootstocks of tomato, eggplant, and nightshade grafting increased the scion biomass of C. betacea seedlings by 146.1%, 23.2%, and 94.5%, respectively, compared with the un-grafted seedlings. Moreover, tomato, eggplant, and nightshade rootstocks grafting increased the photosynthesis, superoxide dismutase activity, and peroxidase activity, while reducing the catalase activity and soluble protein content of C. betacea seedlings. Although all three rootstocks grafting decreased Se contents in rootstock roots and stems, only nightshade rootstock grafting increased Se content in the scions of C. betacea seedlings. Notably, root biomass, catalase activity, soluble protein content, rootstock root Se content, and rootstock stem Se content were closely related to the scion Se content. These findings suggest that only grafting onto nightshade rootstock significantly enhances Se uptake in C. betacea, whereas tomato and eggplant rootstocks grafting have no effect on Se uptake.

Community Structure and Diversity of Rhizosphere Soil and Endophytic Bacteria during the Period of Growth of Moso Bamboo Shoots.

The purpose of this study was to elucidate the community structure of rhizosphere soil bacteria and endophytic bacteria during the growth of moso bamboo (Phyllostachys edulis) shoots. This study collected the rhizospheric soil samples, tissue samples of rhizome roots, shoot buds, winter bamboo shoots, spring bamboo shoots, and samples of forest soil. Their metagenomic DNA was extracted, and the bacterial community structure and diversity characteristics were compared and analyzed using high-throughput sequencing technology. These samples enabled the identification of 32 phyla, 52 classes, 121 orders, 251 families, and 593 genera of bacteria. The phyla primarily included Proteobacteria, Acidobacteria, and Cyanobacteria among others. Proteobacteria was the dominant phylum in the samples of bamboo shoots and rhizome roots, whereas Acidobacteria was dominant in the rhizosphere and forest soil samples. The predominant genera of the rhizome root samples were Acidothermus, Bradyrhizobium and Acidobacterium, and the predominant genera of the soil samples were Acidothermus and Acidobacterium. This study preliminarily revealed the regularity between the growth and development of bamboo shoots and the changes in the community structure of rhizosphere soil and endophytic bacteria, which provides insights into the relationship between growth and the bacterial community structure in different stages of bamboo shoots.

Additional far-red light promotes adventitious rooting of double-root-cutting grafted watermelon seedlings

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 auxin-related 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.

Rapid In Vitro Screening of Prunus Genotypes for Resistance to Armillaria Root Rot Using Roots of Young Rootstocks

Armillaria root rot (ARR), caused by Armillaria species and Desarmillaria tabescens, is a severe disease that affects stone fruit trees in the United States. One strategy to mitigate the impact of this disease is to develop ARR-resistant rootstocks. However, current techniques to screen Prunus species for resistance to ARR are time-consuming, labor-intensive, and may not fully replicate field conditions. To address these limitations, we developed a new rapid in vitro screening assay, which uses roots of 2-year-old Prunus rootstock genotypes. We screened 12 Prunus genotypes against Armillaria mellea, Armillaria solidipes, and Desarmillaria tabescens in vitro. Freshly excavated root segments were placed next to or on top of fungal cultures. After 21 days, the circumferential percentage and horizontal length of the fungal colonization and the ability of the fungus to enter through root periderm were evaluated. The root tissue surrounding the infection was also evaluated to assess any response reactions against the ARR pathogens. Our results showed that inoculated root tissues displayed signs of fungal infection, and infection and host responses varied among the Prunus genotypes. Host responses similar to those observed in the field, such as compartmentalization of infected tissue with barrier zones, necrophylactic periderm formation, and callus formation on root surfaces, were observed and were more evident in less susceptible genotypes. In conclusion, our newly developed assay, which uses freshly excavated roots from 2-year-old rootstocks, can rapidly screen Prunus genotypes for resistance to ARR.

Growth, biochemical and physiological response of grapevine rootstocks to copper excess in nutrient solution

Frequent applications of cupric fungicides on grapevines increase copper (Cu) content in vineyard soils, and can lead to phytotoxicity, mainly in young grapevines. Thus, is necessary to identify rootstocks that are tolerant to Cu excess, as well as understanding the mechanisms against high Cu concentrations. The aim of this study was to assess the growth, biochemical and physiological response of grapevine rootstocks to Cu excess in nutrient solution. Two experiments were carried out: Experiment 1 used Vitis rotundifolia cv. Magnolia rootstocks and Experiment 2 used Paulsen 1103 (Vitis berlandieri X Vitis rupestris) rootstocks. The rootstocks were cultivated with different Cu concentrations in nutrient solution (in µM): 0.12; 20; 40 and 80. The high Cu concentrations had negative effect on growth of both grapevine rootstocks. The highest Cu concentrations were observed in roots in both rootstocks. Magnolia rootstock showed the greatest tolerance to Cu excess in nutrient solution, with less absorbed Cu as well as less Cu translocation to shoots. Hydrogen peroxide concentrations and lipid peroxidation increased in shoots and roots of both rootstocks with increased Cu concentrations. The size and rusticity of Magnolia plants may have influenced their response to the excess of Cu in the solution in comparison to Paulsen plants.

Potential role of Fusarium spp. in grapevine decline

Despite studies associating Fusarium spp. with grapevine decline since late 1970s, no consensus has been reached regarding the roles these fungi play in grapevine health. Recent studies in British Columbia, Canada, assessed prevalence of grapevine trunk diseases (GTDs) in young and mature vineyards, and the presence of GTD fungi in ready-to-plant nursery material sold in Canada. This study characterized the Fusarium spp. isolated from grapevines in BC by sequencing part of the translation elongation factor 1-alpha (TEF1) gene, and carried out pathogenicity studies to determine whether Fusarium plays a role in grapevine decline. Fusarium spp. were isolated from 9.8% of samples collected from young vines (≤ 8-year-old), and 7.3% from mature vines (> 8-year-old), showing decline symptoms in commercial vineyards. Fusarium was also isolated from 43.9% of ready-to-plant dormant grapevines analyzed from four nurseries. Fusarium incidence varied between plants within the same nursery and between plants from the different nurseries. DNA sequences of TEF1 allowed identification of Fusarium oxysporum, F. proliferatum, F. ramigenum, and a Fusarium sp. Pathogenicity studies were conducted in 1-year-old dormant rooted ‘Chardonnay’ plants grafted onto ‘3309C’ rootstock, and treatments included: i) whole plant, ii) trimming of roots, iii) cut at rootstock basal ends, and iv) trimming of roots plus cut at rootstock basal ends. Plants were inoculated using standardized methods, and were then planted in a greenhouse. Fusarium was compared with Dactylonectria macrodidyma, D. pauciseptata and Ilyonectria liriodendri used as positive controls. The Fusarium spp. caused necroses in rootstock roots and basal ends that were similar to those caused by black-foot fungi. Fusarium spp. and black-foot fungi reduced root and shoot dry weights when compared with non-inoculated controls, but no statistically significant differences were recorded for most treatments. This study is the first in Canada to identify Fusarium spp. from grapevines. Though Fusarium was common in these grapevines, pathogenicity tests suggest that the identified Fusarium spp. were weakly pathogenic to ‘3309C’ rootstock grapevines.

Patterns of Copper Bioaccumulation and Translocation in Grapevine Grafts Depending on Rootstocks

The long-term use of copper (Cu) fungicides in viticulture in Europe has led to Cu accumulation in vineyard top soils. However, less is known about the accumulation of Cu in grapevine grafts after the callusing process/before planting in the nursery. This paper presents the capacity of 5BB and SO4 rootstocks to accumulate Cu, as well as the patterns of translocation in the grafts. After heat forcing (callusing), the grapevine grafts of Sauvignon Blanc on 5BB and SO4 rootstocks were grown in pots for six months in a glasshouse and exposed to various Cu formulations (Cu-oxychloride, Cu-gluconate) and concentrations in peat (50, 150, 500, and 1000 mg Cu of dry weight (DW)). In addition to monitoring the shoot growth dynamics and analyzing the copper content in graft organs, bioaccumulation (BAFs) and translocation factors (TFs) of Cu were calculated. The mean Cu concentrations were ranked as follows: roots (15–164) > rootstock trunks (8–38) > canes (5–21) mg kg−1 DW. The Cu concentrations depended on the Cu formulation and concentration in the substrate. Higher Cu content was found in the roots of both rootstocks (5BB and SO4, 23–155 and 15–164 mg kg−1 DW, respectively) and the lowest in the canes (less than 10 mg kg−1 DW) of grafts grown in Cu-oxychloride-treated peat. Based on the BAFs and TFs, both rootstocks could be considered as Cu exclusive. A higher translocation rate was determined in systemic Cu-gluconate and SO4 rootstock. With shoot length measurements, the significant inhibitory effects of Cu on grapevine grafts growth could not be confirmed, despite the inhibitory effects that were clearly expressed in the first two months of growth. Soils containing more than 500 mg Cu/kg−1 are less suitable for growing vine grafts.

Comparing the performance of Cyperus papyrus and Typha domingensis for the removal of heavy metals, roxithromycin, levofloxacin and pathogenic bacteria from wastewater

Contamination of heavy metals and antibiotics would threaten the water and soil resources. Phytoremediation can be potentially used to remediate metal and antibiotics contaminated sites. The current study was carried out over a period of 12 months to assess the efficiency of the macrophytes Typha domingensis and Cyperus papyrus with different substrate materials to remove heavy metals and two antibiotics, roxithromycin and levofloxacin, from wastewater for reuse in agriculture. The concentrations of seven heavy metals (copper, nickel, iron, cadmium, zinc, lead, and chromium) in water and plant tissues were determined. The results showed that C. papyrus had a greater capacity than T. domingensis to remove biochemical oxygen demand (BOD) (80.69%), chemical oxygen demand (COD) (69.87%), and ammonium (NH4+) (69.69%). Cyperus papyrus was more effective in retaining solid pollutants. The bioaccumulation factors (BCF) roots of C. papyrus were higher levels of most metals than those of T. domingensis. The highest root–rhizome translocation factor (TF) values of C. papyrus were higher than T. domingensis. The bacterial indicators (total and fecal coliforms, as well as Faecal streptococci) and the potential pathogens (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) showed removal efficiencies ranging between 96.9% and 99.8%. The results indicated that the two systems could significantly reduce the concentration of antibiotics in wastewater, with roxithromycin showing higher elimination rates than levofloxacin. The results showed maximum removal of the heavy metals in constructed wetlands CWs planted with T. domingensis. The presence of zeolite and C. papyrus in the effluent of CWs significantly improved treatment capacity and increased pollutant removal efficiency.

Grazing intensity effects on sward responses of UF Riata Bahiagrass

AbstractBahiagrass (Paspalum notatum Flüggé) is a rhizomatous, perennial, warm‐season forage widely grown in the southeastern United States "UF Riata" bahiagrass is more upright growing with greater herbage production when days are shorter compared with most other cultivars. Lesser daylength sensitivity extends the grazing season, but in combination with more upright growth may negatively affect persistence under grazing, especially if out‐of‐season herbage production interferes with normal reserve storage. This 3‐year study investigated above and belowground sward responses of UF Riata bahiagrass to three levels of post‐grazing herbage mass (HM) (500 [heavy grazing, HG], 1500 [moderate grazing], or 2500 [light grazing, LG] kg DM ha−1, where DM is dry matter) imposed by mob stocking every 14 days. Total herbage accumulation (HA) and HA rate were not affected by treatment. Crude protein (CP) was affected by treatment × grazing cycle × year, whereas in vitro digestible organic matter concentrations were affected by treatment × year and grazing cycle × year. Root–rhizome biomass (12,940–9230 kg OM ha−1, where OM is organic matter) and soil cover percentage (97%–93%) decreased linearly as grazing intensity increased from LG to HG. Proportion of non‐planted grasses was 34% and 17% in HG and LG swards, respectively. Proportion of non‐grass weeds increased across treatments from 2% to 22% over the years. Moderate grazing could maintain similar CP to HG, and similar root–rhizome biomass to LG. Thus, considering both sward persistence and forage nutritive value, a target post‐grazing HM of ≈1500 kg DM ha−1 is recommended when UF Riata pastures are grazed every 2 weeks.

Inoculation with arbuscular mycorrhizal fungi increase calcium uptake in Malus robusta

Utilization of plants-microbe's interactions to remediate calcium11Ca: calcium (Ca) deficiency soils is effective and practical. A greenhouse pot experiment was conducted to evaluate the effect of arbuscular mycorrhizal fungi22AMF: arbuscular mycorrhizal fungi (AMF) inoculation and the synergy of AMF and Ca fertilizer on physiological and transcriptomic responses in apple rootstock (Malus robusta) roots. AMF and Ca fertilizer synergistically served to elongate root length, surface area, average stem diameter and biomass, such extended the surface area in contact with soil nutrients and water. Symbiosis of AMF with apple seedlings made significantly higher levels of Ca in root tissue and promoted Ca translocation from roots to shoot tissue. GO and KEGG pathway analysis disclosed that gene expression varies in several critical gene families, such as auxin response (MdAux/IAAs, MdGH3 and MdSAUR), TCA cycles (MdCS, MdMDH and MdACO), phosphate transporters (MdPHT1;1, MdPHT1;10 and MdPHT1;3) and Ca2+ signal transduction pathways (MdCa2+/ATPase, MdCML, MdTPC1 and MdCDPK), indicating that apple regulates the expression of genes related to auxin synthesis, organic acid secretion, and calcium transporters and channels, thereby increased the growth of apple roots and promoted the secretion of organic acids, resulting in the increase of calcium effectiveness in soil. AMF promoted the accumulation and utilization of Ca in plants by regulating the expression levels of genes related to these pathways. These results contribute to a better understanding of AMF symbiosis mechanism behind the Ca uptake of apple seedlings under exogenous Ca treatment.

Comparative physiological, metabolomic, and transcriptomic analyses reveal mechanisms of apple dwarfing rootstock root morphogenesis under nitrogen and/or phosphorus deficient conditions.

Nitrogen (N) and phosphorus (P) are essential phytomacronutrients, and deficiencies in these two elements limit growth and yield in apple (Malus domestica Borkh.). The rootstock plays a key role in the nutrient uptake and environmental adaptation of apple. The objective of this study was to investigate the effects of N and/or P deficiency on hydroponically-grown dwarfing rootstock 'M9-T337' seedlings, particularly the roots, by performing an integrated physiological, transcriptomics-, and metabolomics-based analyses. Compared to N and P sufficiency, N and/or P deficiency inhibited aboveground growth, increased the partitioning of total N and total P in roots, enhanced the total number of tips, length, volume, and surface area of roots, and improved the root-to-shoot ratio. P and/or N deficiency inhibited influx into roots, and H+ pumps played a important role in the response to P and/or N deficiency. Conjoint analysis of differentially expressed genes and differentially accumulated metabolites in roots revealed that N and/or P deficiency altered the biosynthesis of cell wall components such as cellulose, hemicellulose, lignin, and pectin. The expression of MdEXPA4 and MdEXLB1, two cell wall expansin genes, were shown to be induced by N and/or P deficiency. Overexpression of MdEXPA4 enhanced root development and improved tolerance to N and/or P deficiency in transgenic Arabidopsis thaliana plants. In addition, overexpression of MdEXLB1 in transgenic Solanum lycopersicum seedlings increased the root surface area and promoted acquisition of N and P, thereby facilitating plant growth and adaptation to N and/or P deficiency. Collectively, these results provided a reference for improving root architecture in dwarfing rootstock and furthering our understanding of integration between N and P signaling pathways.

Effects of high- and low-yield moso bamboo (Phyllostachys edulis) forests on bacterial community structure

To study the characteristics of bacterial community structure in high-yield and low-yield moso bamboo (Phyllostachys edulis) forests, we collected bamboo rhizome, rhizome root, stem, leaf, rhizosphere soil, and non-rhizosphere soil from high- and low-yield forests in Yong'an City and Jiangle County of Fujian Province, China. The genomic DNA of the samples was extracted, sequenced and analyzed. The results show that: the common differences between the high-yield and low-yield P. edulis forest samples in the two regions were mainly in bacterial community compositions in the bamboo rhizome, rhizome root, and soil samples. Differences in the bacterial community compositions in the stem and leaf samples were insignificant. The bacterial species and diversity in rhizome root and rhizosphere soil of high-yield P. edulis forests were less than those of low-yield forests. The relative abundance of Actinobacteria and Acidobacteria in rhizome root samples of high-yield forests was higher than that in low-yield forests. The relative abundance of Rhizobiales and Burkholderiales in bamboo rhizome samples in high-yield forests was higher than that in low-yield forests. The relative abundance of Bradyrhizobium in bamboo rhizome samples in high-yield forests was higher than that in low-yield forests in the two regions. The change of bacterial community composition in P. edulis stems and leaves showed little correlation with high- or low-yields of P. edulis forests. Notably, the bacterial community composition of the rhizome root system was correlated with the high yield of bamboo. This study provides a theoretical basis for using of microbes to enhance the yields of P. edulis forests.

4-methylumbelliferone (4-MU) enhances drought tolerance of apple by regulating rhizosphere microbial diversity and root architecture.

The dwarfing rootstocks-mediated high-density apple orchard is becoming the main practice management. Currently, dwarfing rootstocks are widely used worldwide, but their shallow root system and drought sensitivity necessitate high irrigation requirements. Here, the root transcriptome and metabolome of dwarfing (M9-T337, a drought-sensitive rootstock) and vigorous rootstocks (Malus sieversii, a drought-tolerant species, is commonly used as a rootstock) showed that a coumarin derivative, 4-Methylumbelliferon (4-MU), was found to accumulate significantly in the roots of vigorous rootstock under drought condition. When exogenous 4-MU was applied to the roots of dwarfing rootstock under drought treatment, the plants displayed increased root biomass, higher root-to-shoot ratio, greater photosynthesis, and elevated water use efficiency. In addition, diversity and structure analysis of the rhizosphere soil microbial community demonstrated that 4-MU treatment increased the relative abundance of putatively beneficial bacteria and fungi. Of these, Pseudomonas, Bacillus, Streptomyces, and Chryseolinea bacterial strains and Acremonium, Trichoderma, and Phoma fungal strains known for root growth, or systemic resistance against drought stress, were significantly accumulated in the roots of dwarfing rootstock after 4-MU treatment under drought stress condition. Taken together, we identified a promising compound-4-MU, as a useful tool, to strengthen the drought tolerance of apple dwarfing rootstock.

Performance of a Leaf-Galling Phylloxera (Daktulosphaira vitifoliae) on Roots of Diverse Vitis spp. Rootstocks in North East Victoria, Australia

Background and Aims. Grape phylloxera in Australia comprises diverse genetic strains that feed on roots and leaves of Vitis spp. The G38 phylloxera strain was detected on roots of Vitis spp., for the first time in North East Victoria in 2015. Prior to 2015, G38 phylloxera was only known to feed on leaves. The aim of this study was to evaluate the survival and development of G38 phylloxera on roots of diverse Vitis spp. under field, controlled laboratory, and greenhouse conditions. Methods and Results. In the field, emergence traps quantified first instars and alates emerging from roots of diverse rootstocks and Vitis vinifera L. High numbers of phylloxera were collected in traps placed at vines of rootstocks 101-14, 3309 Courderc and Schwarzmann. Nodosity were also observed on roots of 101-14, 3309 Courderc and Schwarzmann in the field and in-pot vines experiments. The better performance of G38 phylloxera on these three rootstocks compared to V. vinifera in the field and in potted vines parallelled the excised roots experiments. Conclusions. The relatively high performance of G38 phylloxera on the 101-14, 3309 Courderc and Schwarzmann rootstocks suggest a susceptible response and could be associated with rootstock parentage. Further investigation is warranted to determine implications for rootstocks development. Significance of the Study. These findings are fundamental for decision-making in phylloxera risk assessment and rootstock selection. The study reaffirms the need for triphasic (in vitro, in planta, and in-field) rootstock screening protocols for phylloxera.

Effects of Different Types of Potassium Fertilizers on Nutrient Uptake by Grapevine

Potassium (K) is the most important element for fruit quality improvement. This study aimed at determining the best K fertilizer type that can promote grape growth and nutrient uptake. Specifically, four types of K fertilizers (complex fertilizer, potassium nitrate, potassium sulfate, and potassium dihydrogen phosphate) were applied to grapevines grown in plastic pots, and then their effects on grape growth and nutrient uptake were explored. Results showed that the complex fertilizer and potassium nitrate treatments increased the biomass of the grapevine plants, whereas the other fertilizers had no significant effects on the biomass. Only the potassium nitrate treatment increased the contents of photosynthetic pigments in grapevine leaves. The complex fertilizer and potassium nitrate treatments increased the total N content in the grapevine plants to some extent, whereas the other fertilizer treatments decreased the total N content to some extent. It was also evident that all four K fertilizers increased the total P and K contents in the grapevine plants. Compared to the control, the complex fertilizer, potassium nitrate, potassium sulfate, and potassium dihydrogen phosphate treatments increased the scion total P content by 20.18%, 9.77%, 12.52%, and 30.81%, respectively, and increased the scion total K content by 15.37%, 8.41%, 20.15%, and 26.48%, respectively. In addition, correlation and grey relational analyses showed that the rootstock stem total N content, rootstock root biomass, and soil alkali-hydrolyzable N concentration were the top three indicators most closely associated with the scion total N content, whereas the rootstock root total P content, soil available P concentration, and rootstock stem total P content were the top three indicators most closely associated with the scion total P content. Additionally, the rootstock root total K content, soil available K concentration, and rootstock root total P content were the top three indicators most closely associated with the scion total K content. Overall, the different K fertilizers can all promote the uptake of P and K by grapevine plants, and the potassium dihydrogen phosphate fertilizer is the best choice.

Effect of Rhodiola rosea Rhizome and Punica granatum Fruit Peel on the Metabolic Processes and Physiological Activity of Rats Fed with Excessively Fat Diet.

Rhodiola rosea (golden root) and Punica granatum (pomegranate), as well as a number of other species of medicinal plants, exert an array of biological effects: adaptogenic, antioxidant and anti-inflammatory. However, there are not enough contemporary studies of their influence on metabolic processes, especially in cases of imbalanced diet. Lipid dysregulation is the main reason for many diseases, including obesity, cardiovascular disorders, non-alcoholic fatty liver disease, hypertension, atherosclerosis and insulin resistance. Recently, a growing amount of evidence has suggested the positive effects of certain natural nutrients on lipid metabolism. The work aims to define the general effect of golden root rhizome and pomegranate peel on physiological activity and metabolic processes in model animals fed with excessively fat diet. This study is relevant for the development of drugs and food additives for treatment and prophylaxis of metabolism disorders. In a 30-day experiment, we determined the effect of golden root (Rhodiola rosea L.) rhizome and pomegranate (Punica granatum L.) peel on the physiological activity and metabolic processes of 24 laboratory rats consuming a high-fat diet. The physical activity was evaluated according to the mass gain of animals and change in the relative mass of the internal organs, and also the functional conditions of the central nervous system, as demonstrated by the indicators of the locomotor activity and emotional status, determined in the open field test. The influence on the metabolic processes was revealed by biochemical and clinical blood analyses. Body mass of rats fed with golden root (R. rosea) reached 125.8 % of the initial body mass; when fed on pomegranate (P. granatum), it reached 123.9 %; and the control group reached only 111.5 % of the initial body mass. The rhizomes of R. rosea in the diet of male rats during the month of the experiment did not cause significant changes in the relative organ mass, and the pomegranate peel fruits led to a decrease in the thymus relative mass, as well as liver and brain. R. rosea rhizomes in the rats' diet led to an increase in the activity of alkaline phosphatase, and also to a decrease in the concentration of urea and urea nitrogen. Diet supplemented with R. rosea also contributed to a strong decrease in plasma concentrations of bilirubin and triglycerides (up to 57.0 % compared with the concentration in the control group). The rhizomes of R. rosea contributed to an unreliable decrease in the atherogenicity index. The pomegranate peel also greatly increased alkaline phosphatase activity and reduced plasma triglyceride concentrations. In addition, in rats consuming the peel of P. granatum, blood glucose concentration decreased. Under the influence of P. granatum, a strong increase in the atherogenic index of plasma (up to 518.6 % of the control) was observed because of a decrease in the concentration of high-density lipoproteins (up to 57.1 %) and a simultaneous elevation of the concentration of low-density lipoproteins (up to 158.3 % of the control). Open field test between groups remained without significant changes. The results indicate that the rhizome of R. rosea and peel of P. granatum are safe as food additives to high-fat diet and did not cause pathological changes and side effects, and at the same time significantly influence the metabolic processes (lipid and carbohydrate). Our study theoretically substantiates the use of R. rosea rhizome and P. granatum peel for the production of nutraceutical and pharmacological products for the correction of metabolic disorders of people and animals. Doses and periods of their application require further research.

Roots originating from different shoot parts are functionally different in running bamboo, Phyllostachys glauca

Abstract Running bamboos are a group of clonal plants exhibiting rapid and widespread expansion. They possess two root subsystems, arising from different shoot parts, culm roots and rhizome roots. To date, it remains unclear what the functional differences are between the two root subsystems and what their relation is to the remarkably competitive ability of running bamboos. A typical running bamboo, Phyllostachys glauca, which dominates in a highly heterogeneous habitat of limestone hills, was sampled to compare the morphology, architecture, anatomy, chemical composition, mechanics and nutrient acquisition of the two root subsystems to explore their differences in functional traits. Compared with rhizome roots, culm roots possessed greater tensile strength, modulus of elasticity, stele diameter to root diameter ratio, root tissue density, root length density, rooting depth, basal diameter of shoot‐borne roots and more lignified cells. Culm roots also had a higher phosphorus (P) concentration (>0.4 mg g−1), which was nearly twice that of rhizome roots. By contrast, rhizome roots exhibited a greater specific root area, specific root length, cortex thickness to root radius ratio, total branch order and greater P‐uptake capacity than culm roots. Our findings revealed distinct differences in functional traits between culm roots and rhizome roots in P. glauca. Culm roots are considered to primarily provide anchorage, but also function in resource acquisition and nutrient storage, while rhizome roots mainly play a role in resource acquisition. Except for the anchorage and resource acquisition of culm roots, the extra resource acquisition by rhizome roots and the high concentration of a limiting nutrient (P) in culm roots enhance the performance in a highly heterogeneous habitat which offers a physiological explanation for P. glauca dominating on limestone hills. The functional differentiation between culm roots and rhizome roots provides insight into the mechanism underpinning the remarkable expansion of running bamboos and offers a new perspective to explain the strong competitive ability of clonal plants with dimorphic roots. Read the free Plain Language Summary for this article on the Journal blog.

Methods of adventitious rooting of rootstocks for quince trees

The aim was to evaluate techniques to enhance the adventitious rooting of ‘Adams’, ‘BA-29’, ‘EMA’, ‘EMC’ and ‘Sydo’ (Cydonia oblonga) quince trees as well as Chaenomeles sinensis quince trees with a rootstock for C. oblonga. Woody and semihardwood cuttings were removed from six quince trees, and the rooting capacity was evaluated. Seedlings of the C. sinensis rootstock were produced, and double grafting was performed using the six quince trees as intergrafting and ‘Bereckzi’ as grafts and the anatomical sections were evaluated. The seedlings were transplanted to pots. Half the length of the intergrafting was buried to stimulate adventitious rooting. Double grafting is viable. A low rooting capacity is observed for the ‘BA-29’ and C. sinensis quince tree combination, both in their cuttings and when they are the intergrafting.