Search Results (15)

Dwarfing rootstocks are widely used in apple production to control tree vigor and improve fruit quality. However, their adoption in ‘Fuji’ orchards remains limited by high production costs and unstable field performance. In this study, five rootstock materials, namely GM256, GM310, MD001, LiaoZhen 2, and Malus hupehensis Rehd (CK), were evaluated for their effects on cold tolerance, tree growth, and fruit quality in ‘Fuji’ apple. Cold tolerance was assessed using electrolyte leakage and related physiological indicators under low-temperature stress. MD001 and GM256 exhibited significantly stronger cold tolerance than the control, as indicated by lower LT₅₀ values and more favorable physiological responses (p < 0.05). Regarding tree growth, GM310 showed the weakest dwarfing effect, while LiaoZhen 2 had a relatively high proportion of long shoots, suggesting excessive vegetative growth. Meanwhile, GM256 produced the highest yield among all combinations. Principal component analysis of fruit-quality traits indicated that GM256 and GM310 performed better overall than the other combinations. In addition, GM256 produced significantly higher soluble solids, vitamin C content, and sugar–acid ratio than the control and most other rootstocks (p < 0.05). Overall, GM256 combined strong cold tolerance, a balanced shoot composition, moderate tree vigor, and high fruit quality, suggesting that it is a promising rootstock for ‘Fuji’ apple cultivation in Shandong Province. Full article

Arbuscular mycorrhizal fungi (AMF) affect cadmium (Cd) accumulation and tolerance in host plants. However, the effects of AMF on Cd accumulation and phytotoxicity and their underlying mechanism in apples remain uncharacterized. In this study, the comprehensive physiological and molecular responses of uninoculated and Rhizophagus intraradices-inoculated Malus hupehensis Rehd. rootstocks exposed to 0 or 300 μM Cd were investigated. AMF inoculation mitigated Cd-induced growth and photosynthesis inhibition and nutrient ion disorders. It also lowered the concentrations of Cd in all tissues and reduced Cd transport to the shoots. Compared to uninoculated apple plants, those inoculated with mycorrhizal fungi reduced the mobility and toxicity of Cd by altering its form and binding it to the cell walls of the roots and leaves. AMF inoculation ameliorated Cd stress by altering endogenous phytohormone levels and triggering enzymatic and non-enzymatic antioxidant systems. Transcriptome analysis revealed that the differentially expressed genes (DEGs) associated with AMF under Cd stress regulated carbohydrate and amino acid biosynthesis and metabolism, as well as phytohormone biosynthesis and signal transduction. Furthermore, AMF inoculation downregulated certain genes involved in Cd uptake and transport while upregulating other genes involved in detoxification. These results suggest that AMF alleviate Cd phytotoxicity by orchestrated physiological and transcriptomic regulation in M. hupehensis Rehd., providing valuable insights into the efficacy of AMF inoculation in improving the heavy metal resistance of fruit trees. Full article

The effectiveness of chlorine dioxide as a soil disinfectant for the prevention and control of apple replant disease (ARD) remains largely unexplored. This study aimed to determine the optimal concentration of chlorine dioxide for soil disinfection and to evaluate its impact on the prevention and control of ARD. The experimental results indicated that a high concentration of 600 mg·L⁻¹ chlorine dioxide exhibited a potent lethal effect on both the hyphae and spores of pathogenic Fusarium. Results from pot experiments demonstrated that, compared with the replant control, the height, ground diameter, fresh weight, and dry weight of Malus hupehensis Rehd. seedlings treated with 600 mg·L⁻¹ chlorine dioxide increased by 27.20%, 15.95%, 100.70%, and 76.28%, respectively. Additionally, the root length, surface area, volume, and number of root tips of the seedlings increased by 31.74%, 96.54%, 257.29%, and 85.29%, respectively. The activities of root-protective enzymes, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), also increased to varying degrees, whereas the malondialdehyde (MDA) content was significantly reduced compared with the control treatment. Furthermore, the number of soil fungi treated with chlorine dioxide and the concentration of phenolic acid compounds in replant soil were significantly reduced. Treatment with 600 mg·L⁻¹ chlorine dioxide significantly decreased the detected copy number of genes associated with soil-borne pathogenic Fusarium, optimized the soil microbial community structure, and reduced the relative abundance of pathogenic fungi. In summary, disinfection of replant soil using 600 mg·L⁻¹ chlorine dioxide can enhance the growth of M. hupehensis Rehd. seedlings, inhibit the growth and reproduction of pathogenic Fusarium fungi, improve the soil environment, and effectively prevent and control ARD. Full article

Nine new compounds (1–9), including four dihydrochalcone glycosides, two dibenzofuran glycosides, and two biphenyl glycosides, were isolated from the leaves of the medicinal plant Malus hupehensis collected in Shennongjia Forestry District (Hubei, China). Their structures were elucidated by comprehensive spectroscopic techniques, including HRESIMS and NMR spectra. All compounds were tested by preliminary biological evaluation for their α-glucosidase inhibitory and NO production activities. Compound 4 was found to show significant inhibitory activity against NO production in LPS-activated RAW 264.7 macrophage cells with an IC₅₀ value of 29.60 μM, and compounds 3 and 4 were found to exhibit potent α-glucosidase inhibition with IC₅₀ values of 44.17 and 60.15 μM, respectively. This work represents the first report of the diverse glycosides from the plant Malus hupehensis. It expands our understanding of the secondary metabolites of this medicinal plant and lays the foundation for the study of the bioactive principles of the ethnic hypoglycemic medicinal plant. Full article

Apple replant disease (ARD) is a serious threat to newly replanted apple seedlings. The alleviation of ARD is of great significance for the healthy development of the apple industry. In this study, we investigated the effects of leaf fermentation products (LFP) of Allium sativum L. on the replanted soil environment and Malus hupehensis Rehd. seedlings. The results showed that LFP increased biomass accumulation, changed root architecture, increased root anti-oxidant enzyme activity, and decreased root MDA content under replanted conditions. In addition, the application of LFP increased soil nutrients and soil enzyme activity and reduced phenolic acid content. Furthermore, the LFP enriched the number of beneficial bacteria and reduced the number of harmful fungi, which positively affected the soil microbial community structure. Overall, our results demonstrated that LFP of A. sativum L. could alleviate the occurrence of ARD and provide new insights for the reuse of the leaves of A. sativum L. and the prevention of ARD. Full article

This study aimed to determine the effects of the nitrogen (N) application period and level on the fate of fertilizer N and the contribution of N absorption and translocation to apple organ N. Two N application periods (labeled by the ¹⁵N tracer technique in spring and summer, represented by SP and SU, respectively) and three N levels (N0, MN, and HN) were used to determine the physiological indexes and aboveground, root, and soil ¹⁵N content of 4-year-old dwarf (‘Red Fuji’/M9T337) and arborized (‘Red Fuji’/Malus hupehensis Rehd.) apple trees. The results showed that HN led to shoot overgrowth, which was not conducive to the growth of the apple root system (root length, root tips, root surface area, and root volume) or the improvement of root activity. The contribution of soil N to apple organ N accounted for more than 50%, and the contribution of N application in summer to fruit N was higher than that in spring. Under HN treatment, the proportion of soil N absorbed by trees decreased, while that of fertilizer N increased; however, the highest proportion was still less than 50%, so apple trees were highly dependent on soil N. Under MN treatment, fertilizer N residue was similar to soil N consumption, and soil N fertility maintained a basic balance. Under HN treatment, fertilizer N residue was significantly higher than soil N consumption, indicating that excessive N application increased fertilizer N residue in the soil. Overall, the ¹⁵N utilization rate of arborized trees (17.33–22.38%) was higher than that of dwarf trees (12.89–16.91%). A total of 12.89–22.38% of fertilizer ¹⁵N was absorbed by trees, 30.37–35.41% of fertilizer ¹⁵N remained in the soil, and 44.65–54.46% of fertilizer ¹⁵N was lost. The ¹⁵N utilization rate and ¹⁵N residual rate of summer N application were higher than those of spring N application, and the ¹⁵N loss rate was lower than that of spring N application. High microbial biomass N (MBN) may be one of the reasons for the high N utilization rate and the low loss rate of N application in summer. Full article

Due to the aging of trees, aged apple and cherry orchards need to be rebuilt urgently. However, due to the limitation of land resources, it is inevitable to rebuild the apple orchard by taking the aged cherry orchard as a replacement, which will lead to replant disease and seriously affect the sustainable development of the horticulture industry. This study investigated the effect of aged cherry orchard soil on the growth of M. hupehensis seedlings grown in pots, and it was further verified that allelochemicals in soil were one of the reasons for this effect. Three treatments were implemented: aged apple orchard soil (ppl), aged cherry orchard soil (pyl), and aged cherry orchard soil after fumigation with methyl bromide (pyz). Compared with pyz, pyl treatment significantly decreased the biomass, root growth, and antioxidant enzyme activity of M. hupehensis seedlings, and increased the content of MDA. Compared with ppl, pyl contains a smaller number of fungi and bacteria, but the abundance of the four disease-causing Fusarium remained high. In addition, the levels of allelochemicals found in the soil of aged cherry orchards can inhibit the normal growth and development of M. hupehensis seedlings. Amygdalin most strongly inhibited these seedlings. In summary, directly planting M. hupehensis seedlings in the soil of the aged cherry orchards still inhibits their normal growth and development, although the seedlings grow better than in aged apple orchard soil. Therefore, it is not feasible to directly plant M. hupehensis seedlings in the soil of aged cherry orchards, and measures should be taken to eliminate allelochemicals such as amygdalin and harmful microorganisms. Full article

Apomixis is a unique reproductive process that produces fertile offspring without the combination of sperm and egg cells. This process perfectly reproduces maternal DNA, making it possible to fix heterosis during reproduction. Malus shizongensis is a newly discovered species that is closely related to Malus hupehensis Rehd. After de-male bagging, it was found that the fruit set rate reached 78.7%. Preliminary analysis indicated that M. shizongensis have apomictic reproductive characteristics. In this work, we employed paraffin sectioning and electron scanning microscopy to explore apomixis in M. shizongensis during the development of male–female gametes and embryo sacs. Stigma fluorescence assays showed that pollen germination was normal, but less pollen entered the ovaries. Additionally, analysis of anthers indicated the presence of dysplasia and paraffin sectioning revealed that the pollen mother cells were aborted due to abnormal disintegration of the tapetum layer. Taken together, our results indicate that the primary causes of apomixis in M. shizongensis are anther dysplasia and male gamete development failure, resulting in reduced pollen tube entry into ovaries and reduced reproduction of female gametes. In conclusion, this study provide a theoretical basis and technical supports for apple stock breeding and apple industry development. Full article

Apple replant disease (ARD) is seriously hindering the development of the apple industry. This experiment assessed the effects of two different root-growth-promoting agents (Indoleacetic acid and nutrient elements) on the microbial environment of apple-replanted soil and the growth of apple rootstock Malus hupehensis Rehd. seedlings after fumigation with crystal lime sulfur. The results showed that the simultaneous application of crystal lime sulfur, indoleacetic acid, and nutrient elements (T4) improved the biomass of Malus hupehensis Rehd. seedlings. It also enhanced the activities of soil enzymes and root antioxidant enzymes (SOD, POD, CAT). Their activities were significantly higher than in the individual treatments and resulted in a decrease in malondialdehyde (MDA) content. The T4 treatment significantly increased the net photosynthetic rate and chlorophyll content of the plant, thus effectively increasing the plant growth status. After fumigation, the amount of soil microorganisms was reduced, and the amount of bacteria and actinomycetes was increased after mixed application with the root-growth-promoting agent. The abundance of different species such as Pseudallescheria, Guehomyces, Trichoderma, Bacillus, Gaiella, and Sphingomonas was effectively increased, and the amount of Fusarium oxysporum was reduced. Through correlation analysis between different species and plant and soil enzymes, we found that the different species were positively correlated with root respiration rate and SOD activity and negatively correlated with MDA content. The differentially accumulated microbial species may be the key microorganism that promotes plant growth. Therefore, the simultaneous application of crystal lime sulfur, indoleacetic acid, and nutrient elements can optimize the apple replant soil environment and promote the growth of Malus hupehensis Rehd. seedlings, and can be used to control apple replant disease. Full article

Malus is an economically important plant that is widely cultivated worldwide, but it often encounters saline–alkali stress. The composition of saline–alkali land is a variety of salt and alkali mixed with the formation of alkaline salt. Hydrogen sulfide (H₂S) has been reported to have positive effects on plant responses to abiotic stresses. Our previous study showed that H₂S pretreatment alleviated the damage caused by alkaline salt stress to Malus hupehensis Rehd. var. pingyiensis Jiang (Pingyi Tiancha, PYTC) roots by regulating Na⁺/K⁺ homeostasis and oxidative stress. In this study, transcriptome analysis was used to investigate the overall mechanism through which H₂S alleviates alkaline salt stress in PYTC roots. Simultaneously, differentially expressed genes (DEGs) were explored. Transcriptional profiling of the Control-H₂S, Control-AS, Control-H₂S + AS, and AS-H₂S + AS comparison groups identified 1618, 18,652, 16,575, and 4314 DEGs, respectively. Further analysis revealed that H₂S could alleviate alkaline salt stress by increasing the energy maintenance capacity and cell wall integrity of M. hupehensis roots and by enhancing the capacity for reactive oxygen species (ROS) metabolism because more upregulated genes involved in ROS metabolism and sulfur-containing compounds were identified in M. hupehensis roots after H₂S pretreatment. qRT-PCR analysis of H₂S-induced and alkaline salt-response genes showed that these genes were consistent with the RNA-seq analysis results, which indicated that H₂S alleviation of alkaline salt stress involves the genes of the cell wall and sulfur-containing compounds in PYTC roots. Full article

Organic acids secreted by plants, such as p-hydroxybenzoic acid, ferulic acid, cinnamic acid, and benzoic acid, can inhibit seed germination and root growth. The effects of root and soil leaching liquor from orchards on the growth of M. hupehensis Rehd. seedlings under sand culture are studied; the seedlings are sampled at 15, 30, 45, and 60 d. Changes in the amount of root exudates are determined using HPLC. Low concentrations of root leaching liquor (A1) and soil leaching liquor (B1) significantly promoted plant growth and chlorophyll synthesis; high concentrations of root leaching liquor (A6) and soil leaching liquor (B4–6) inhibited growth. Low concentrations of soil leaching liquor had no significant effect on the POD, SOD, and CAT activities. A5–6 and B5–6 significantly decreased Fv/Fm and qP values, respectively, and increased NPQ values. All root and soil leaching liquor treatments inhibited the secretion of gallic acid, hydroxybenzoic acid, benzoic acid, and phloridzin, and promoted the secretion of caffeic acid. The root leaching liquor treatments inhibited the secretion of catechin and promoted the secretion of phloretin. The soil leaching liquor treatments promoted the secretion of cinnamic acid. The secretion of other phenolic acids is likely associated with the different concentrations of leaching liquor. Full article

Apple replant disease (ARD) is a common soil disease that occurs in apple-growing areas around the world, causing root tip rot and necrosis, plant growth retardation and even plant death. Biofumigation is a promising strategy for controlling ARD due to its advantages of convenient application and being environmentally friendly. Tagetes erecta is an effective biological fumigant, but its effect on ARD is unclear. In the present study, we used Malus hupehensis Rehd. seedlings as the test material to detect the mitigating effects of different forms of T. erecta: air-dried sample (DS), fresh samples (FS) and fresh sample infusion solution (IS) on ARD. The effects of different forms of T. erecta on the growth of apple seedlings, leaf photosynthesis, root antioxidant enzyme, soil enzymatic activity and microbial environment were investigated. Compared with the CK treatments, DS, FS, and IS treatments all significantly increased the biomass of apple seedlings and promoted root growth under replanting conditions. Among them, DS showed the best results. The activity of antioxidant enzyme including superoxide dismutase, peroxidase and catalase were significantly increased in roots grown in soils treated with T. erecta. Moreover, T. erecta treatment also increased the activity of soil urease, phosphatase, sucrase and catalase enzyme, significantly altered the abundance of soil fungal communities and, in particular, reduced the abundance of Fusarium oxysporum, the main causal fungus of ARD. Therefore, our results suggest that biofumigation of different forms of T. erecta enhanced the resistance of ARD by regulating root reactive oxygen levels and improving the soil fungal communities. Full article

Trichoderma asperellum strain 6S-2 with biocontrol effects and potential growth-promoting properties was made into a fungal fertilizer for the prevention of apple replant disease (ARD). 6S-2 fertilizer not only promoted the growth of Malus hupehensis Rehd seedlings in greenhouse and pot experiments, but also increased the branch elongation growth of young apple trees. The soil microbial community structure changed significantly after the application of 6S-2 fertilizer: the relative abundance of Trichoderma increased significantly, the relative abundance of Fusarium (especially the gene copy numbers of four Fusarium species) and Cryptococcus decreased, and the relative abundance of Bacillus and Streptomyces increased. The bacteria/fungi and soil enzyme activities increased significantly after the application of 6S-2 fertilizer. The relative contents of alkenes, ethyl ethers, and citrullines increased in root exudates of M. hupehensis Rehd treated with 6S-2 fertilizer and were positively correlated with the abundance of Trichoderma. The relative contents of aldehydes, nitriles, and naphthalenes decreased, and they were positively correlated with the relative abundance of Fusarium. In addition, levels of ammonium nitrogen (NH₄-N), nitrate nitrogen (NO₃-N), available phosphorus (AP), available potassium (AK), organic matter (SOM), and pH in rhizosphere soil were also significantly related to changes in the microbial community structure. In summary, the application of 6S-2 fertilizer was effective in alleviating some aspects of ARD by promoting plant growth and optimizing the soil microbial community structure. Full article

As a traditional Chinese drink, tea is favored for its rich flavor and its medicinal functionality. In this study, the in vitro bioactivities of Wushanshencha (WST; a local tea from Chongqing, China), which is processed mainly from the leaves of the wild Malus hupehensis (Pamp.) Rehd.). We assessed the scavenging capacity of tea extracts on 1, 1-diphenyl-2-picrylhydrazyl (DPPH); 2, 2′-azino-bis (3-ethylbenzthiazoline-6- sulphonic acid) diammonium salt (ABTS); and hydroxyl (OH) free radicals, and demonstrate the high antioxidant activity and dose-dependent relationship of these extracts. We also detail the anti-mutagenic effect of these tea extracts against the Salmonella typhimurium TA98 strain induced by the 2, 7-diaminofluorene (2, 7-AF) mutagen and the TA100 strain induced by the N-methyl-N′-nitro- N- nitrosoguanidine (MNNG) mutagen at concentrations of 1.25 and 2.50 mg/plate, respectively, with the high-dose groups showing better results. We investigated the anticancer mechanisms of WST extracts (40, 100, and 160 μg/mL) in HepG2 human hepatoma cells via 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay and quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR). The results showed that the proliferation of HepG2 cells was significantly inhibited in a dose-dependent manner by the tea extracts. Moreover, apoptosis in HepG2 cells was induced via upregulation of Caspase-3, Caspase-7, Caspase-8, Caspase-9, p21, p53, and Bax as well as downregulation of Bcl-2 apoptosis-associated factors, as assessed via mRNA expression levels after treating with WST extracts. The expression of inflammation-related factors, e.g., NF-κB, and Cox-2, was significantly downregulated by the WST extracts, demonstrating its inflammatory properties. Together, these observations indicated that WST extracts have anti-inflammatory and anti-cancer properties. In addition, high-performance liquid chromatography (HPLC) analysis showed that WST extracts contained chlorogenic acid, 4-hydroxycinnamic acid, isoquercitrin, taxifolin, quercitrin, rosmarinic acid, myricetin, baicalin, neosperidin dihydrochalcone, and quercetin. As such, WST appears to be an effectively functional drink, due to its rich functional components and anti-cancer activity. Full article

Since melatonin was identified in plants decades ago, much attention has been devoted to discovering its role in plant science. There is still a great deal to learn about the functional importance of melatonin, as well as its functional mode. In this paper, we examine the role of melatonin treatment in the response of Malus hupehensis Rehd. to alkaline conditions. Stressed seedlings showed chlorosis and suppressed growth. However, this phenotype was ameliorated when 5 µM melatonin was added to the irrigation solution. This supplementation was also associated with a reduction in cell membrane damage and maintenance of a normal root system architecture. Fewer reactive oxygen species (ROS) were accumulated due to the enhanced scavenging activity of antioxidant enzymes superoxide dismutase, peroxidase, and catalase. In addition, alkaline-stressed seedlings that received the melatonin supplement accumulated more polyamines compared with untreated seedlings. Transcript levels of six genes involved in polyamine synthesis, including SAMDC1, -3, and -4, and SPDS1, -3, and -5, -6, were upregulated in response to melatonin application. All of these results demonstrate that melatonin has a positive function in plant tolerance to alkaline stress because it regulates enzyme activity and the biosynthesis of polyamines. Full article