Search

We used 256 apple germplasm resources for a thorough examination of the genetic diversity associated with 26 phenotypic traits (i.e., genetic diversity analysis, cluster analysis, correlation analysis, principal component analysis, and membership function). The average coefficient of variation for 12 morphological traits was 66.39% (21.10–201.5%). The coefficient of variation was highest and lowest for the fruit arris and the width of the eye basin, respectively. Additionally, the diversity index ranged from 0.54 to 1.33. Moreover, the coefficient of variation for 14 numerical traits varied from 5.37% to 50%. The titratable acid content had the highest coefficient of variation, with a diversity index ranging from 2.01 to 2.08 (average of 2.045). A cluster analysis categorized 256 germplasms into four groups, among which Group I included germplasms with large fruits and the best comprehensive performance. Of the top 10 principal components revealed by the principal component analysis, principal component 1 was mainly related to fruit size and flavor. The top 10 germplasms were selected on the basis of comprehensive scores using the membership function method. Furthermore, a stepwise regression analysis identified 15 key traits for identifying apple germplasms, including the vegetative growth day, fruit weight, and the firmness of the fruit without skin. These results can serve as the foundation for future analyses of the phenotypic diversity of apple germplasms, while also providing a theoretical basis for screening, characterizing, and further improving excellent apple germplasms. [ABSTRACT FROM AUTHOR]

Summary: In plants under drought stress, sugar content in roots increases, which is important for drought resistance. However, the molecular mechanisms for controlling the sugar content in roots during response to drought remain elusive. Here, we found that the MdDOF3‐MdHT1.2 module‐mediated glucose influx into the root is essential for drought resistance in apple (Malus × domestica). Drought induced glucose uptake from the rhizosphere and up‐regulated the transcription of hexose transporter MdHT1.2. Compared with the wild‐type plants, overexpression of MdHT1.2 promoted glucose uptake from the rhizosphere, thereby facilitating sugar accumulation in root and enhancing drought resistance, whereas silenced plants showed the opposite phenotype. Furthermore, ATAC‐seq, RNA‐seq and biochemical analysis demonstrated that MdDOF3 directly bound to the promoter of MdHT1.2 and was strongly up‐regulated under drought. Overexpression of MdDOF3 in roots improved MdHT1.2‐mediated glucose transport capacity and enhanced plant resistance to drought, but MdDOF3‐RNAihr apple plants showed the opposite phenotype. Moreover, overexpression of MdDOF3 in roots did not attenuate drought sensitivity in MdHT1.2‐RNAi plants, which was correlated with a lower glucose uptake capacity and glucose content in root. Collectively, our findings deciphered the molecular mechanism through which glucose uptake from the rhizosphere is mediated by MdDOF3‐MdHT1.2, which acts to modulate sugar content in root and promote drought resistance. [ABSTRACT FROM AUTHOR]

Packaging is one of the least automated steps among all the fruit postharvest processes, which is time-consuming and labor-intensive. Therefore, a robust suction strategy for robotic manipulation needs to be developed. In this research, a geometric-based apple suction strategy for robotic packaging was studied, including suction cup design, optimal suction region selection algorithm, and robot system integration. In the first place, on the basis of the geometric features of the spheroid fruit, the structure of the suction cups was designed to provide reliable suction force. Then, suction force measurement experiments on both acrylic balls and apples were conducted. Based on the results, the parameters of the suction cup were finally determined. The results also indicated that the curvature radius of the suction region is supposed to larger than that of the suction cups. Furthermore, a robust suction region selection algorithm was developed, which involves four steps: RGB-D information acquisition, object detection and point cloud generation, spherical fitting, and suction region selection. Finally, the above methods were integrated into a robotic packaging system. In addition, on the basis of spatial-frequency domain imaging (SFDI) technology, early stage bruise was detected for validation. The results showed that, the proposed suction strategy and system is potential for robust robotic apple packaging. [ABSTRACT FROM AUTHOR]

Inadequate lateral branch development can lead to decreased apple (Malus ×domestica Borkh.) orchard productivity and profitability in modern high-density orchard systems. Although plant growth regulator applications are used to increase lateral branching on leaders of young apple trees, inconsistent responses have been observed in the southeastern United States. In North Carolina and Washington, three experiments were conducted to identify effective leader management strategies to increase lateral branching. Effects and interactions of leader bagging, 6-benzyladenine (6-BA), and 6-BA + gibberellic acid (GA4+7) on lateral branch development of 1-year-old leaders were evaluated. Across all experiments, leader bagging was an influential factor. When compared with unbagged trees, leader bagging increased lateral branch number (20% to 48%), number of feathers (74% to 125%), average branch length (28% to 34%), and total linear bearing surface (428%) of the treated section of the leader. Blossom cluster density and final fruit set were increased in bagged trees, 65% and 36%, respectively. At the rates and timings tested, 6-BA and 6-BA + GA4+7 were generally ineffective in stimulating lateral branching and interactions among the factors evaluated were not influential. Leader bagging was an effective lateral branch induction strategy, although the mechanism of action is poorly understood. Future research to characterize the bagged environment and/or physiological responses to bagging may aid in the development of future environmentally sustainable technologies to stimulate lateral branching of apple trees. [ABSTRACT FROM AUTHOR]

Fresh apples are vulnerable to Listeria monocytogenes (L. monocytogenes) contamination during handling and storage causing subsequent foodborne outbreaks. Gaseous chlorine dioxide (ClO2) is an effective antimicrobial agent against L. monocytogenes and could augment food safety. This study investigates the stress and virulence response of L. monocytogenes on apples exposed to a sublethal concentration of ClO2. L. monocytogenes was inoculated on the surface of apples and exposed to gaseous ClO2 for 1 h. Gene expression analysis via Real‐Time quantitative polymerase chain reaction (RT‐qPCR) revealed minimal changes in gene expression compared to control samples. However, a surface‐dependent response was observed, with slight upregulation of relevant virulence (hly) and stress (clpC) genes on more hydrophilic surfaces. These findings indicate that gaseous ClO2 treatment can provide a biostatic effect against L. monocytogenes on fresh produce, shedding light on its antimicrobial mechanism and potential for enhancing apple safety. [ABSTRACT FROM AUTHOR]

SUMMARY: Anthocyanin generation in apples (Malus domestica) and the pigmentation that results from it may be caused by irradiation and through administration of methyl jasmonate (MeJA). However, their regulatory interrelationships associated with fruit coloration are not well defined. To determine whether MdERF109, a transcription factor (TF) involved in light‐mediated coloration and anthocyanin biosynthesis, has synergistic effects with other proteins, we performed a yeast two‐hybrid assessment and identified another TF, MdWER. MdWER was induced by MeJA treatment, and although overexpression of MdWER alone did not promote anthocyanin accumulation co‐overexpression with MdERF109 resulted in significantly increase in anthocyanin biosynthesis. MdWER may form a protein complex with MdERF109 to promote anthocyanin accumulation by enhancing combinations between the proteins and their corresponding genes. In addition, MdWER, as a MeJA responsive protein, interacts with the anthocyanin repressor MdJAZ2. Transient co‐expression in apple fruit and protein interaction assays allowed us to conclude that MdERF109 and MdJAZ2 interact with MdWER and take part in the production of anthocyanins upon MeJA treatment and irradiation. Our findings validate a role for the MdERF109‐MdWER‐MdJAZ2 module in anthocyanin biosynthesis and uncover a novel mechanism for how light and MeJA signals are coordinated anthocyanin biosynthesis in apple fruit. Significance Statement: Our findings validate a role for the MdERF109‐MdWER‐MdJAZ2 module in anthocyanin biosynthesis and uncover a novel mechanism for how light and MeJA signals are coordinated anthocyanin biosynthesis in apple fruit. [ABSTRACT FROM AUTHOR]

SUMMARY: Watercore is a common physiological disease of Rosaceae plants, such as apples (Malus domestica), usually occurring during fruit ripening. Apple fruit with watercore symptoms is prone to browning and rotting, thus losing commercial viability. Sorbitol and calcium ions are considered key factors affecting watercore occurrence in apples. However, the mechanism by which they affect the occurrence of watercore remains unclear. Here, we identified that the transcription factor MdWRKY9 directly binds to the promoter of MdSOT2, positively regulates the transcription of MdSOT2, increases sorbitol content in fruit, and promotes watercore occurrence. Additionally, MdCRF4 can directly bind to MdWRKY9 and MdSOT2 promoters, positively regulating their expression. Since calcium ions can induce the ubiquitination and degradation of the transcription factor MdCRF4, they can inhibit the transcription of MdWRKY9 and MdSOT2 by degrading MdCRF4, thereby reducing the sorbitol content in fruit and inhibiting the occurrence of fruit watercore disease. Our data sheds light on how calcium ions mitigate watercore in fruit, providing molecular‐level insights to enhance fruit quality artificially. [ABSTRACT FROM AUTHOR]

The health effects of 100% fruit and vegetable juices (FVJ) represent a controversial topic. FVJ contain notable amounts of free sugars, but also vitamins, minerals, and secondary compounds with proven biological activities like (poly)phenols and carotenoids. The review aimed to shed light on the potential impact of 100% FVJ on human subject health, comprehensively assessing the role each type of juice may have in specific health outcomes for a particular target population, as reported in dietary interventions. The effects of a wide range of FVJ (orange, grapefruit, mandarin, lemon, apple, white, red, and Concord grapes, pomegranate, cranberry, chokeberry, blueberry, other minor berries, sweet and tart cherry, plum, tomato, carrot, beetroot, and watermelon, among others) were evaluated on a series of outcomes (anthropometric parameters, body composition, blood pressure and vascular function, lipid profile, glucose homeostasis, biomarkers of inflammation and oxidative stress, cognitive function, exercise performance, gut microbiota composition and bacterial infections), providing a thorough picture of the contribution of each FVJ to a health outcome. Some juices demonstrated their ability to exert potential preventive effects on some outcomes while others on other health outcomes, emphasising how the differential composition in bioactive compounds defines juice effects. Research gaps and future prospects were discussed. Although 100% FVJ appear to have beneficial effects on some cardiometabolic health outcomes, cognition and exercise performance, or neutral effects on anthropometric parameters and body composition, further efforts are needed to better understand the impact of 100% FVJ on human subject health. [ABSTRACT FROM AUTHOR]

Fungal endophytes inhabit a similar ecological niche to that occupied by many phytopathogens, with several pathogens isolated from healthy tissues in their latent phase. This study aimed to evaluate the pathogenicity, the colonisation ability, and the enzyme activity of 37 endophytic fungal isolates recovered from apparently healthy apple shoot and leaf tissues. The pathogenicity of the isolates was assessed on 'Royal Gala' and 'Braeburn' fruit and detached 'Royal Gala' shoots. For the non-pathogenic isolates, their ability to endophytically colonise detached 'Royal Gala' shoots was evaluated. Enzyme activity assays were undertaken to determine whether the pathogenicity of the endophytes was related to the production of the extracellular enzymes, amylase, cellulase, pectinase, protease, and xylanase. Of the 37 isolates studied, eight isolates, representing the genera Colletotrichum , Diaporthe , Fusarium, and Penicillium, were shown to be pathogenic on both apple shoots and fruit. Two isolates identified as Trichoderma atroviride , were pathogenic only on shoots, and three isolates, representing the genus Diaporthe , were pathogenic only on fruit. Of the remaining 24 isolates, 22 (Biscogniauxia (n = 8), Chaetomium (n = 4), Trichoderma (n = 3), Epicoccum (n = 2), Neosetophoma (n = 2), Xylaria (n = 1), Daldinia (n = 1), and Paraphaeosphaeria (n = 1)) were recovered from the inoculated apple shoots but two failed to colonise the shoot tissues. Of the isolates tested, 20 produced amylase, 15 cellulase, 25 pectinase, 26 protease, and 13 xylanase. There was no correlation between the range and type of enzymes produced by the isolates and their pathogenicity or ability to endophytically colonise the shoot tissue. The study showed that approximately one-third (13/37) of the isolates recovered from the apparently healthy apple shoot tissues were observed as latent pathogens. The isolates that did not cause disease symptoms may have the ability to reduce colonisation of apple tissues by pathogens including Neonectria ditissima associated with European canker of apple. • Latent plant pathogens isolated from healthy plant tissue identified as endophytes. • Pathogenicity and enzyme production of 37 fungal apple endophyte isolates assessed. • Thirteen isolates produced disease symptoms on apple fruit and/or detached shoots. • Twenty-two isolates endophytically colonised apple shoots, with no symptoms. • Enzyme production did not differentiate between pathogenic and endophytic isolates. [ABSTRACT FROM AUTHOR]

Sunburn is possibly the main problem affecting the apple production in the Southern Hemisphere including Chile. This study focused on determining the effect of shade nets to reduce sunburn incidence and reflective mulch to improve colour on canopy microclimate, vegetative growth, fruit quality, return bloom and profitability of two apple cultivars ('Gala Baigent' and 'Fuji Raku Raku') in southern Chile. The treatments evaluated were net, mulch, net + mulch. Trees without net or mulch served as the control. Results showed that PAR transmitted under the netting was reduced in an average of 26% and the mulch increased the reflected PAR from 3% to 5% (grass row control) to 20%–37%. Shoot length, yield, fruit maturity and return bloom were not affected using either net or mulch. The incidence of sunburn under net was reduced by 76%–80%, compared to the control; however, it also reduced fruit colouration, especially in 'Fuji Raku Raku'. The use of mulch under shade net increased the amount in 27% and 9% (average of seasons) of fruit in the Premium category of colour for 'Gala Baigent' and 'Fuji Raku Raku', respectively, which is only economically justified in circumstances of high incidence of sunburn and limitations of fruit colour. [ABSTRACT FROM AUTHOR]

Patterned hair loss (PHL) or androgenetic alopecia is a condition affecting about 50% of people worldwide. Several pharmacological medications have been developed over the years, but few studies have investigated their effectiveness. Therefore, new, safer and more effective strategies are required. Recent investigations showed that Annurca apple extract application could induce keratin production and promote hair growth thanks to the high amount of procyanidin B2 contained in. Hence, this study aimed to investigate the role of an Annurca apple extract in preventing PHL by testing it on human follicle dermal papilla cells (HFDPCs) for the first time. Treatment of HFDPCs with Annurca apple extract counteracted intracellular reactive oxygen species accumulation by increasing the activity of antioxidant enzymes such as superoxide dismutase 2 and catalase. Furthermore, treatment with Annurca apple extract increased β‐catenin and fibroblast growth factor 2, which are involved in hair growth stimulation. These data suggest that Annurca apple extract may be a potential therapeutically useful nutraceutical product for preventing or treating hair loss by reducing oxidative stress and inducing the expression of hair growth‐related factors. [ABSTRACT FROM AUTHOR]

In vitro mass propagation of apple plants plays an important role in the rapid multiplication of genetically uniform, disease-free scions and rootstocks with desired traits. Successful micropropagation of apple using axillary shoot cultures is influenced by several factors, the most critical of which is the cytokinin included in the culture medium. The impact of medium composition from single added cytokinins on shoot proliferation of apple scion Húsvéti rozmaring cultured on agar-agar gelled Murashige and Skoog medium fortified with indole butyric acid and gibberellic acid was investigated. The optimum concentration for efficient shoot multiplication differs according to the type of cytokinin. The highest significant multiplication rate (5.40 shoots/explant) was achieved using 2.0 μM thidiazuron while the longest shoots (1.80 cm) were observed on the medium containing benzyladenine at a concentration of 2.0 μM. However, application of either thidiazuron or benzyladenine as cytokinin source in the medium resulted in shoots of low quality, such as stunted and thickened shoots with small leaves. In the case of benzyladenine riboside, the 8 μM concentration was the most effective in increasing the multiplication rate (4.76 shoots/explant) but caused thickened stem development with tiny leaves. In the present study, meta-topolin was shown to be the most effective cytokinin that could be applied to induce sufficient multiplication (3.28 shoots/explant) and high-quality shoots along with shoot lengths of 1.46 cm when it was applied at concentrations of 4 μM. However, kinetin was the least active cytokinin; it practically did not induce the development of new shoots. The superior cytokinin for in vitro axillary shoot development of apple scion Húsvéti rozmaring with high-quality shoots was the meta-topolin, but it may be different depending on the variety/genotype under study. [ABSTRACT FROM AUTHOR]

The need for the increasing geographical spread of fire blight (FB) affecting fruit crops to be addressed led to large-scale chemicalization of the environmental matrices and reduction of plant productivity. The current study aimed to assess the effects of novel biopreparations at different exposure durations on photosynthetic pigment content and antioxidant enzyme activity in leaves of apple and pear varieties with varying levels of resistance to FB. Biopreparations were formulated from a cultural broth containing Lacticaseibacillus paracasei M12 or Bacillus amyloliquefaciens MB40 isolated from apple trees' phyllosphere. Aseptic leaves from blight-resistant (endemic Malus sieversii cv. KG10), moderately resistant (Pyrus pyraster cv. Wild), and susceptible (endangered Malus domestica cv. Aport and Pyrus communis cv. Shygys) varieties were employed. The impact of biopreparations on fruit crop antioxidant systems and photosynthetic apparatuses was investigated in vitro. Study results indicated that FB-resistant varieties exhibit enhanced adaptability and oxidative stress resistance compared to susceptible ones. Plant response to biopreparations varied based on the plant's initial FB sensitivity and exposure duration. Indeed, biopreparations improved the adaptive response of the assimilation apparatus, protein synthesis, and catalase and superoxide dismutase activity in susceptible varieties, suggesting that biopreparations have the potential for future commercialization to manage FB in fruit crops. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Dwarf apple is one of the most important forms of garden economy, which has become a new engine for rural revitalization. The effective detection of coloring and ripening apples in complex environments is important for the sustainable development of smart agricultural operations. Addressing the issues of low detection efficiency in the greenhouse and the challenges associated with deploying complex target detection algorithms on low-cost equipment, we propose an enhanced lightweight model rooted in YOLOv7. Firstly, we enhance the model training performance by incorporating the Squeeze-and-Excite attention mechanism, which can enhance feature extraction capability. Then, an SCYLLA-IoU (SIoU) loss function is introduced to improve the ability of extracting occluded objects in complex environments. Finally, the model was simplified by introducing depthwise separable convolution and adding a ghost module after up-sampling layers. The improved YOLOv7 model has the highest AP value, which is 10.00%, 5.61%, and 6.00% higher compared to YOLOv5, YOLOv7, and YOLOX, respectively. The improved YOLOv7 model has an MAP value of 95.65%, which provides higher apple detection accuracy compared to other detection models and is suitable for potted dwarf anvil apple identification and detection. [ABSTRACT FROM AUTHOR]

Apples are usually bagged during the growing process, which can effectively improve the quality. Establishing an in situ nondestructive testing model for in-tree apples is very important for fruit companies in selecting raw apple materials for valuation. Low-maturity apples and high-maturity apples were acquired separately by a handheld tester for the internal quality assessment of apples developed by our group, and the effects of the two maturity levels on the soluble solids content (SSC) detection of apples were compared. Four feature selection algorithms, like ant colony optimization (ACO), were used to reduce the spectral complexity and improve the apple SSC detection accuracy. The comparison showed that the diffuse reflectance spectra of high-maturity apples better reflected the internal SSC information of the apples. The diffuse reflectance spectra of the high-maturity apples combined with the ACO algorithm achieved the best results for SSC prediction, with a prediction correlation coefficient (Rp) of 0.88, a root mean square error of prediction (RMSEP) of 0.5678 °Brix, and a residual prediction deviation (RPD) value of 2.466. Additionally, the fruit maturity was predicted using PLS-LDA based on color data, achieveing accuracies of 99.03% and 99.35% for low- and high-maturity fruits, respectively. These results suggest that in-tree apple in situ detection has great potential to enable improved robustness and accuracy in modeling apple quality. [ABSTRACT FROM AUTHOR]

'Ruixue' apples were used as the test material to study the effect of 10 μM methyl jasmonate (MeJA) on the quality and cell wall metabolism of apples after 18 d of storage. The results showed that MeJA significantly decreased the respiratory rate, reduced the titratable acid content and maintained a high soluble solids content. MeJA has been shown to suppress the activities and gene expressions of WSP, CSP, ISP, and cellulose in contrast to the control group, thereby maintaining a lower cell permeability and higher exocarp firmness. MeJA significantly decreased the expression of MdACS, MdACO, MdPL, Mdgal, and MdPG genes in the apple exocarp when compared to the control group. In addition, the overexpression of MdPL18 increased the content of cell wall polysaccharides such as WSP and CSP, enhanced cell wall-degrading enzyme activities, and accelerated fruit ripening and softening, whereas silencing MdPL18 did the opposite. Together, these results demonstrate that exogenous MeJA maintains the Ruixue apple fruit quality by regulating the metabolism of cell wall substances. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging, as a non-destructive testing technique with the ability to acquire rich spatial and spectral information, is a potential tool for fruit bruise detection. However, the cost issue is one of the main reasons limiting the popularity of this technique. In addition, it is difficult to detect the entire surface of samples such as fruits due to the uncertainty of the damaged area. Furthermore, directional scattering on the target sample can lead to bright spots and shadows on the acquired hyperspectral image, which can affect the image quality and add additional preprocessing steps. Therefore, a monochromatic illumination model based on the combination of Xenon lamp and reflective grating is proposed. An experimental prototype of the system has realized 101 spectral channels in the 400–700 nm range. The sample is placed in an optical integrating sphere with rollers for indirect illumination to avoid spots and shadows during image acquisition, enabling multi-surface imaging. This prototype is then used to prepare hyperspectral datasets of sound apples and bruised apples. Models built using classic classification algorithms SVM (87.5%), k-NN (82.5%) AlexNet (95%), VGG16 (95%), ResNet (100%), and achieve effective results in tests. The results demonstrate that the HSI system we designed has exceptional performance in apple mechanical damage detection and classification, showing the advantages of good spectral resolution, low cost, and low thermal effect. [ABSTRACT FROM AUTHOR]

Visible Near-infrared (Vis/NIR) transmittance spectroscopy has been employed to evaluate various quality indicators of fruits, owing to the advantages of rapid non-destructive detection, real-time monitoring, and applicability to opaque samples. The portable Vis/NIR transmittance system was autonomously developed and coupled with chemometrics methods for the detection of quality indicators including soluble solids content (SSC), watercore degree, firmness and pH of apples. Preprocessing method of Savitzky-Golay (SG) smoothing combined with standard normal variate SNV) transformation was employed to mitigate spectra noise. The feature variables were selected using variable selection methods and coupled with partial least square (PLS) to establish linear regression prediction models. Furthermore, a deep learning model was developed by combining competitive adaptive reweighted sampling (CARS) with convolutional neural network (CNN). The Rp of SSC, firmness, pH and the watercore degree of CARS-CNN model were 0.951, 0.824, 0.828 and 0.943, respectively, and the prediction performance was improved by 3%, 11.2%, 11.2% and 9.3% in comparison with the full-spectra model, respectively. The results indicate that the predictive accuracy of models utilizing CARS-CNN outperformed the other models. This research provides a portable, practical and efficient method for the field of non-destructive detecting of fruit quality to obtain fruit Vis/NIR transmittance spectra and establish quality prediction models. These results demonstrated the feasibility of utilizing the Vis/NIR transmittance spectroscopy combined with CARS-CNN method in the detection of quality indicators for apples. [ABSTRACT FROM AUTHOR]

[Objective] Achieving non-destructive testing of sub-healthy watercore apples. [Methods] First, the logarithmic function method and the power function method proposed by this study were used to correct the sample spectra. Subsequently, the corrected data were converted into different images of gramian angular difference field (GADF), gramian angular summation field (GASF), markov transition field (MTF), recurrence plot (RP), symmetric dot pattern (SDP). Then, the ResNet50 network model with the convolutional block attention module (CBAM) was used to mine the deep image features related to the degree of watercore, which were downscaled by the t-distributed stochastic neighbor embedding (t-SNE) method and analyzed by clustering to determine the most suitable image transformation method. Finally, the most suitable image features were inputted into the improved particle swarm algorithm (IPSO) optimized support vector machine (SVM), extreme learning machine (ELM), k-nearest neighbour (KNN) and random forest (RF) classifier for the three-class classification of watercore apple. [Results] The results showed that the power function method was better than the logarithmic function method in eliminating the effect of diameter on the transmission spectrum. The silhouette coefficient (SC), the calinski harabasz score (CHS), and the davies-bouldin index (DBI) were 0.93, 0.88 and 0.24 after visualization of the image features in the GADF, better than the rest of the image transformation methods. ResNet50-IPSO-ELM achieved the highest classification accuracy of 96.8%. The overall discrimination accuracy of the three watercore classes apples in the test set reached 96.3%, and the stable precision (SP), stable recall (SR), and stable F1-score (SF) were 87.2%, 95.8%, and 92.3%, respectively. [Conclusion] The model maintains a high classification accuracy for the majority class of apples without watercore and healthy apples with watercore and a high discriminatory ability for the minority class of sub-healthy apples with watercore.

A network pharmacological approach was used to predict active ingredients in apples that may have therapeutic effects on hemolysis-induced hyperbilirubinemia and their potential targets, enrichment pathways and action process and to construct adisease-pathway-active component-target network for apples. Autodock software was used to perform molecular docking of key active ingredients and potential targets to verify the reliability of the network analysis results. Furthermore, the effect of apple alcohol extract (AE) on hemolysis-induced hyperbilirubinemia in rats was explored. The results showed that 17 active ingredients of apples with high gastrointestinal absorption and excellent drug-like properties were selected, among which, quercetin, 2α-hydroxyl-ursolic acid, β-sitosterol, phloretin and epicatechin could make important contribution to the treatment of hemolysis-induced hyperbilirubinemia. The top 5 targets in terms of moderate values in the network, including the serine/threonine protein kinase (Akt1), vascular endothelial growth factor A (VEGFA), epidermal growth factor receptor (EGFR), the tyrosine kinase (SRC), and signal transducer and activator of transcription 3 (STAT3) could exert therapeutic effects through the bile secretion pathway, the hypoxia inducible factor (HIF)-1 signaling pathway, the tumor necrosis factor (TNF) signaling pathway and the nuclear factor-kappa B (NF-κB) signaling pathway. Molecular docking was performed on the major active ingredients and the core targets selected by the network, and the results showed a strong affinity between the active ingredients and the potential targets with reliable results from the network analysis. The animal experimental results indicated that compared with the blank control group, the model group had a significant decrease in hemoglobin (HB) levels in the blood and a significant increase in the levels of total bilirubin (TB), indirect bilirubin (IB), alanine transaminase (ALT), aspartate transaminase (AST), TNF-α, and interleukin-6 (IL-6) (P < 0.01). Compared with the model group, HB levels increased and while the levels of TB, IB, ALT, AST, TNF-α and IL-6 significantly decreased in the AE intervention and positive control groups (P < 0.05 or P < 0.01). In summary, apples reduce hemolysis-induced hyperbilirubinemia, which will provide a basis for research on non-invasive therapy for neonatal jaundice.

Malus hybrid 'SH6' (M. honanensis × M. domestica)is a commonly used apple interstock in China, known for its excellent dwarfing characteristics and cold tolerance. In this study, a combined strategy utilizing PacBio HiFi, Hi-C and parental resequencing data were employed to assemble two haploid genomes for 'SH6'. After chromosome anchoring, the final hapH genome size was 596.63 Mb, with a contig N50 of 34.38 Mb. The hapR genome was 649.37 Mb, with a contig N50 of 36.84 Mb. Further analysis predicted that repeated sequences made up 59.69% and 62.52% of the entire genome, respectively. Gene annotations revealed 45,435 genes for hapH and 48,261 genes for hapR. Combined with genomic synteny we suggest that the hapR genome originates from its maternal parent M. domestica cv. Ralls Janet, while the hapH genome comes from its paternal parent, M. honanensis. The assembled genome significantly contributes to the discovery of genes associated with apple dwarfing and the molecular mechanisms governing them. [ABSTRACT FROM AUTHOR]

Background: Fruit appearance of apple (Malus domestica Borkh.) is accession-specific and one of the main criteria for consumer choice. Consequently, fruit appearance is an important selection criterion in the breeding of new cultivars. It is also used for the description of older varieties or landraces. In commercial apple production, sorting devices are used to classify large numbers of fruit from a few cultivars. In contrast, the description of fruit from germplasm collections or breeding programs is based on only a few fruit from many accessions and is mostly performed visually by pomology experts. Such visual ratings are laborious, often difficult to compare and remain subjective. Results: Here we report on a morphometric device, the FruitPhenoBox, for automated fruit weighing and appearance description using computer-based analysis of five images per fruit. Recording of approximately 100 fruit from each of 15 apple cultivars using the FruitPhenoBox was rapid, with an average handling and recording time of less than eleven seconds per fruit. Comparison of fruit images from the 15 apple cultivars identified significant differences in shape index, fruit width, height and weight. Fruit shape was characteristic for each cultivar, while fruit color showed larger variation within sample sets. Assessing a subset of 20 randomly selected fruit per cultivar, fruit height, width and weight were described with a relative margin of error of 2.6%, 2.2%, and 6.2%, respectively, calculated from the mean value of all available fruit. Conclusions: The FruitPhenoBox allows for the rapid and consistent description of fruit appearance from individual apple accessions. By relating the relative margin of error for fruit width, height and weight description with different sample sizes, it was possible to determine an appropriate fruit sample size to efficiently and accurately describe the recorded traits. Therefore, the FruitPhenoBox is a useful tool for breeding and the description of apple germplasm collections. [ABSTRACT FROM AUTHOR]

Background: Phosphorus plays a key role in plant adaptation to adversity and plays a positive role in the yield and quality formation of apples. Genes of the SPX domain-containing family are widely involved in the regulation of phosphorus signalling networks. However, the mechanisms controlling phosphorus deficiency are not completely understood in self-rooted apple stock. Results: In this study, 26 members of the apple SPX gene family were identified by genome-wide analysis, and further divided into four subfamilies (SPX, SPX-MFS, SPX-EXS, and SPX-RING) based on their structural features. The chromosome distribution and gene duplications of MdSPXs were also examined. The promoter regions of MdSPXs were enriched for multiple biotic/abiotic stresses, hormone responses and typical P1BS-related elements. Analysis of the expression levels of 26 MdSPXs showed that some members were remarkably induced when subjected to low phosphate (Pi) stress, and in particular MdSPX2, MdSPX3, and MdPHO1.5 exhibited an intense response to low Pi stress. MdSPX2 and MdSPX3 showed significantly divergent expression levels in low Pi sensitive and insensitive apple species. Protein interaction networks were predicted for 26 MdSPX proteins. The interaction of MdPHR1 with MdSPX2, MdSPX3, MdSPX4, and MdSPX6 was demonstrated by yeast two-hybrid assay, suggesting that these proteins might be involved in the Pi-signaling pathway by interacting with MdPHR1. Conclusion: This research improved the understanding of the apple SPX gene family and contribute to future biological studies of MdSPX genes in self-rooted apple stock. [ABSTRACT FROM AUTHOR]

To compare apple aroma intensities, apples were analyzed from the calyx side (on the opposite side of the stem) using an electronic nose (e-nose) sensor device and direct mass spectrometry. The results indicated that the sensor value tended to increase in accordance with the total intensity of apple aroma components measured by direct mass spectrometry. In addition, the e-nose sensor values for apple aroma did not correlate with the sugar content and ripeness measurements using optical sensors. Moreover, the relative standard deviations of repeatability and intermediate precision in the measurement of apple flavor (apple lip balm) were within 1.36–9.96%. Similar to the utilization of sugar content and ripeness values, the aroma measured from the calyx side can be potentially used for apple evaluation. [ABSTRACT FROM AUTHOR]

SUMMARY: Host‐induced gene silencing (HIGS) is an inherent mechanism of plant resistance to fungal pathogens, resulting from cross‐kingdom RNA interference (RNAi) mediated by small RNAs (sRNAs) delivered from plants into invading fungi. Introducing artificial sRNA precursors into crops can trigger HIGS of selected fungal genes, and thus has potential applications in agricultural disease control. To investigate the HIGS of apple (Malus sp.) during the interaction with Botryosphaeria dothidea, the pathogenic fungus causing apple ring rot disease, we evaluated whether apple miRNAs can be transported into and target genes in B. dothidea. Indeed, miR159a from Malus hupehensis, a wild apple germplasm with B. dothidea resistance, silenced the fungal sugar transporter gene BdSTP. The accumulation of miR159a in extracellular vesicles (EVs) of both infected M. hupehensis and invading B. dothidea suggests that this miRNA of the host is transported into the fungus via the EV pathway. Knockout of BdSTP caused defects in fungal growth and proliferation, whereas knockin of a miR159a‐insensitive version of BdSTP resulted in increased pathogenicity. Inhibition of miR159a in M. hupehensis substantially enhanced plant sensitivity to B. dothidea, indicating miR159a‐mediated HIGS against BdSTP being integral to apple immunity. Introducing artificial sRNA precursors targeting BdSTP and BdALS, an acetolactate synthase gene, into M. hupehensis revealed that double‐stranded RNAs were more potent than engineered MIRNAs in triggering HIGS alternative to those natural of apple and inhibiting infection. These results provide preliminary evidence for cross‐kingdom RNAi in the apple–B. dothidea interaction and establish HIGS as a potential disease control strategy in apple. Significance Statement: To investigate host‐induced gene silencing (HIGS) in apple immunity against Botryosphaeria dothidea, we evaluated the translocation of Malus hupehensis miRNAs during infection and their potential in targeting fungal genes, demonstrating miR159a delivered into fungal cells silenced BdSTP to restrict B. dothidea pathogenicity, which conferred resistance to M. hupehensis. We further explored artificial sRNA precursors as more efficient HIGS triggers targeting selected fungal genes, providing a basis for applying HIGS‐based strategies in controlling B. dothidea in apple. [ABSTRACT FROM AUTHOR]

The effect of plant cultivar on the degree of mycorrhization and the benefits mediated by arbuscular mycorrhizal fungi (AMF) have been documented in many crops. In apple, a wide variety of rootstocks are commercially available; however, it is not clear whether some rootstock genotypes are more susceptible to mycorrhization than others and/or whether AMF species identity influences rootstock compatibility. This study addresses these questions by directly testing the ability/efficacy of four different AMF species (Rhizophagus irregularis, Septoglomus deserticola, Claroideoglomus claroideum or Claroideoglomus etunicatum) to colonize a variety of commercially available Geneva apple rootstock genotypes (G.11, G.41, G.210, G.969, and G.890). Briefly, micropropagated plantlets were inoculated with individual species of AMF or were not inoculated. The effects of the rootstock genotype/AMF interaction on mycorrhization, plant growth, and/or leaf nutrient concentrations were assessed. We found that both rootstock genotype and the identity of the AMF are significant sources of variation affecting the percentage of colonization. However, these factors largely operate independently in terms of the extent of root colonization. Among the AMF tested, C. etunicatum and R. irregularis represented the most compatible fungal partners, regardless of apple rootstock genotype. Among the rootstocks tested, semi-dwarfing rootstocks appeared to have an advantage over dwarfing rootstocks in regard to establishing and maintaining associations with AMF. Nutrient uptake and plant growth outcomes were also influenced in a rootstock genotype/AMF species-specific manner. Our findings suggest that matching host genetics with compatible AMF species has the potential to enhance agricultural practices in nursery and orchard systems. [ABSTRACT FROM AUTHOR]

Fresh-cut apple preservation is a critical concern in the food industry due to the rapid deterioration of texture, color, and flavor. While our previous study introduced apple essence microencapsulation (AEM) to enhance flavor during storage, its impact on overall storage quality was minimal. Thus, this study explores the application of two preservation techniques, namely, slightly acidic electrolyzed water (SAEW) and chitosan–apple essence microencapsulation (CH–AEM) coating, to enhance the quality of fresh-cut apples. Our findings reveal that SAEW treatment significantly reduces the browning index (from 65.38 to 57.36) and respiratory rate (from 5.10% to 4.30% of CO2), and maintains a desirable aroma profile compared to uncoated treatment during 10 days of storage. Additionally, the CH–AEM coating acts as a protective barrier, further preserving the sensory characteristics of fresh-cut apples. Notably, the SAEW–CH–AEM group exhibits superior performance in firmness (8.14 N), respiratory rate (3.37% of CO2), ion leakage (34.86%), and juice yield (47.52%) after 10 days. Our research highlights the synergistic effect of combining these preservation strategies, providing a promising approach for extending the shelf life of fresh-cut apples while maintaining their visual appeal and aromatic quality. These results offer valuable insights for the fresh-cut produce industry, contributing to improved apple product preservation and consumer satisfaction. [ABSTRACT FROM AUTHOR]

Fruit texture and storage properties of various apple varieties exhibit significant variation. The rate of fruit softening post-harvest plays a crucial role in determining fruit quality and shelf life. This research utilized four apple varieties as test subjects to investigate the internal factors influencing fruit texture changes among different varieties. By monitoring changes in relevant physiological indicators during the post-harvest texture softening process, the study examined fruit quality, cell wall material content, hydrolase activity, and gene transcription levels during storage of 'Orin', 'RX', 'RXH', and 'Envy' apples. Initial fruit softening was primarily linked to heightened post-harvest fruit respiration intensity, ethylene production, and rapid amylase activity. Subsequent softening was associated with increased activity of water-soluble pectin (WSP), cellulose (CEL), and other hydrolases. With the extension of the storage period, the fruit cells of the four varieties became more loosely arranged, resulting in larger intercellular gaps. Variations in WSP and cellulose content, CEL activity, and relative expression of Mdβ-gal were observed among the different apple varieties, potentially accounting for the disparities in fruit texture. [ABSTRACT FROM AUTHOR]

The wild relatives of cultivated apples would be an ideal source of diversity for breeding new varieties, which could potentially grow in diverse habitats shaped by climate change. However, there is still a lack of knowledge about the potential distribution of these species. The aim of the presented work was the understand the impacts of climate change on the potential distribution and habitat fragmentation of Caucasian crab apple (Malus orientalis Uglitzk.) and the designation of areas of high interest according to climatic conditions. We used the MaxEnt models and Morphological-Spatial Analysis (MSPA) to evaluate the potential distribution, suitability changes, habitat fragmentation, and connectivity throughout the species range in Turkey, Armenia, Georgia, Russia, and Iran. The results revealed that the potentially suitable range of M. orientalis encompasses 858,877 km², 635,279 km² and 456,795 km² under the present, RCP4.5 and RCP8.5 scenario, respectively. The range fragmentation analysis demonstrated a notable shift in the edge/core ratio, which increased from 50.95% in the current scenario to even 67.70% in the future. The northern part of the range (Armenia, northern Georgia, southern Russia), as well as the central and western parts of Hyrcania will be a core of the species range with suitable habitats and a high connectivity between M. orientalis populations and could work as major refugia for the studied species. However, in the Zagros and central Turkey, the potential range will shrink due to the lack of suitable climatic conditions, and the edge/core ratio will grow. In the southern part of the range, a decline of M. orientalis habitats is expected due to changing climatic conditions. The future outlook suggests that the Hyrcanian forest and the Caucasus region could serve as important refuges for M. orientalis. This study helps to understand spatial changes in species' range in response to climate change and can help develop conservation strategies. This is all the more important given the species' potential use in future breeding programs aimed at enriching the gene pool of cultivated apple varieties. [ABSTRACT FROM AUTHOR]

Background: PC (phytocyanin) is a class of copper-containing electron transfer proteins closely related to plant photosynthesis, abiotic stress responses growth and development in plants, and regulation of the expression of some flavonoids and phenylpropanoids, etc., however, compared with other plants, the PC gene family has not been systematically characterized in apple. Results: A total of 59 MdPC gene members unevenly distributed across 12 chromosomes were identified at the genome-wide level. The proteins of the MdPC family were classified into four subfamilies based on differences in copper binding sites and glycosylation sites: Apple Early nodulin-like proteins (MdENODLs), Apple Uclacyanin-like proteins (MdUCLs), Apple Stellacyanin-like proteins (MdSCLs), and Apple Plantacyanin-like proteins (MdPLCLs). Some MdPC members with similar gene structures and conserved motifs belong to the same group or subfamily. The internal collinearity analysis revealed 14 collinearity gene pairs among members of the apple MdPC gene. Interspecific collinearity analysis showed that apple had 31 and 35 homologous gene pairs with strawberry and grape, respectively. Selection pressure analysis indicated that the MdPC gene was under purifying selection. Prediction of protein interactions showed that MdPC family members interacted strongly with the Nad3 protein. GO annotation results indicated that the MdPC gene also regulated the biosynthesis of phenylpropanoids. Chip data analysis showed that (MdSCL3, MdSCL7 and MdENODL27) were highly expressed in mature fruits and peels. Many cis-regulatory elements related to light response, phytohormones, abiotic stresses and flavonoid biosynthetic genes regulation were identified 2000 bp upstream of the promoter of the MdPC gene, and qRT-PCR results showed that gene members in Group IV (MdSCL1/3, MdENODL27) were up-regulated at all five stages of apple coloring, but the highest expression was observed at the DAF13 (day after fruit bag removal) stage. The gene members in Group II (MdUCL9, MdPLCL3) showed down-regulated or lower expression in the first four stages of apple coloring but up-regulated and highest expression in the DAF 21 stage. Conclusion: Herein, one objective of these findings is to provide valuable information for understanding the structure, molecular evolution, and expression pattern of the MdPC gene, another major objective in this study was designed to lay the groundwork for further research on the molecular mechanism of PC gene regulation of apple fruit coloration. [ABSTRACT FROM AUTHOR]

Introduction: Substantial previous studies have reported that fulvic acid (FA) application plays an important role in Chinese agricultural production. However, little is known about the mechanisms for using FA to increase apple trees resistance to Cd toxicity. In order to clarify the mechanism underlying FA alleviation in Cd-induced growth inhibition in apple seedlings. Methods: Herein, we treated M9T337 seedlings to either 0 or 30 μM/L Cd together with 0 or 0.2 g/L FA and analyzed the root growth, antioxidant enzyme activities, carbon (C) assimilation, nitrogen (N) metabolism, and C and N transport. Results: The results presented that, compared with CK (without Cd addition or FA spraying application), Cd poisoning significantly inhibited the root growth of apple seedlings. However, this Cd-induced root growth inhibition was significantly alleviated by FA spraying relative to the Cd treatment (Cd addition alone). On the one hand, the mitigation of inhibition effects was due to the reduced oxidative damage by enhancing antioxdiant enzyme (SOD, POD, and CAT) activities in leaves and roots. On the other hand, this growth advantage demonstrated compared to the Cd treatment was found to be associated with the strengthen of photosynthetic performance and the elevation of C and N metabolism enzymes activities. Meanwhile, we also found that under Cd stress condition, the distribution of C and N nutrients in apple seedlings was optimised by FA spraying application relative to the Cd treatment, according to the results of 13C and 15N tracing. Conclusion: Conclusively, our results suggested that the inhibitory effect of Cd on apple seedlings root growth was alleviated by FA through regulating antioxdiant capacities and C and N metabolism. [ABSTRACT FROM AUTHOR]

Summary: Nitrogen is an essential nutrient for plant growth and serves as a signaling molecule to regulate gene expression inducing physiological, growth and developmental responses. An excess or deficiency of nitrogen may have adverse effects on plants. Studying nitrogen uptake will help us understand the molecular mechanisms of utilization for targeted molecular breeding.Here, we identified and functionally validated an NAC (NAM‐ATAF1/2‐CUC2) transcription factor based on the transcriptomes of two apple rootstocks with different nitrogen uptake efficiency. NAC1, a target gene of miR164, directly regulates the expression of the high‐affinity nitrate transporter (MhNRT2.4) and citric acid transporter (MhMATE), affecting root nitrogen uptake.To examine the role of MhNAC1 in nitrogen uptake, we produced transgenic lines that overexpressed or silenced MhNAC1. Silencing MhNAC1 promoted nitrogen uptake and citric acid secretion in roots, and enhanced plant tolerance to low nitrogen conditions, while overexpression of MhNAC1 or silencing miR164 had the opposite effect.This study not only revealed the role of the miR164‐MhNAC1 module in nitrogen uptake in apple rootstocks but also confirmed that citric acid secretion in roots affected nitrogen uptake, which provides a research basis for efficient nitrogen utilization and molecular breeding in apple. [ABSTRACT FROM AUTHOR]

Summary: Biosynthesis of flavonoid aglycones and glycosides is well established. However, key genes involved in their catabolism are poorly understood, even though the products of hydrolysis and oxidation play important roles in plant resistance to biotic stress.Here, we report on catabolism of dihydrochalcones (DHCs), the most abundant flavonoids in domesticated apple and wild Malus. Two key genes, BGLU13.1 and PPO05, were identified by activity‐directed protein purification. BGLU13.1‐A hydrolyzed phlorizin, (the most abundant DHC in domesticated apple) to produce phloretin which was then oxidized by PPO05. The process differed in some wild Malus, where trilobatin (a positional isomer of phlorizin) was mainly oxidized by PPO05.The effects of DHC catabolism on apple resistance to biotic stresses was investigated using transgenic plants. Either directly or indirectly, phlorizin hydrolysis affected resistance to the phytophagous pest two‐spotted spider mite, while oxidation of trilobatin was involved in resistance to the biotrophic fungus Podosphaera leucotricha. DHC catabolism did not affect apple resistance to necrotrophic pathogens Valsa mali and Erwinia amylovara.These results suggest that different DHC catabolism pathways play different roles in apple resistance to biotic stresses. The role of DHC catabolism on apple resistance appeared closely related to the mode of invasion/damage used by pathogen/pest. [ABSTRACT FROM AUTHOR]

The conducted experiment evaluated the effects of three fungi—Trichoderma atroviride (Ta), Trichoderma harzianum (Th) and Phytium oligandrum (Po)—on the growth of maidens of two apple cultivars, 'Szampion' and 'Topaz', budded on two rootstocks, M.9 and M.26, in the nursery. The evaluation was based on the number of maidens obtained and their height, trunk diameter and number and length of lateral shoots, as well as the fresh weight of the leaves and the whole maiden. For the weaker-growing maidens of the 'Topaz' cultivar, the activity of the photosynthetic apparatus was additionally measured depending on the rootstock and fungal treatments. The number of maidens obtained improved significantly when Th (8.3–9.0%) and Po (8.4–12.8%) were applied, depending on the rootstock and cultivar used. With the best treatment with the Po fungus, on average, for the two cultivars, maiden apple trees budded on the M.9 dwarf rootstock were characterized by a significantly better height of 6% and trunk diameter of 13% compared to the control. In contrast, trees grown on the M.26 rootstock did not have significantly increased growth after the same treatments, with the exception of the Po fungus, which improved the stem diameter by an average of 10%. The use of fungi stimulated an increase in the number and length of the lateral shoots of maidens of the more easily branching 'Szampion' apple tree cultivar. Based on the fluorescence parameters obtained, it can be assumed that the 'Topaz' cultivar on the M.26 rootstock is less susceptible to stress conditions, especially those related to high temperatures and drought. All fungi used had a positive effect on the activity of the photosynthetic apparatus. Significantly worse values of the fluorescence parameters were obtained for the control combination compared to the fungal treatments. [ABSTRACT FROM AUTHOR]

Most consumers dispose of rotten food without a second thought; however, they also throw away a dynamic group of plant pathogens that can be utilized for inquiry-driven investigations into host/pathogen interactions. Botrytis cinerea is a common necrotrophic fungus that can infect most plants but causes substantial losses to the grape and fresh berry industries. Because most store-bought strawberries eventually succumb to this pathogen (due to the presence of spores from the field or packing facility), they are a dependable source of fungal inoculum to test novel hypotheses about the nature of disease. Across the produce aisle, apples are a diverse, well-characterized, and susceptible host population that enables students to construct individualized experiments about the nature of disease with adequate replication for meaningful analysis. This experimental protocol will outline how to conduct an infection assay with B. cinerea and commercially available apple varieties for students to develop their own experiments, inoculate their own plants, and analyze their own data to answer important questions about how pathogens cause disease. [ABSTRACT FROM AUTHOR]

Anti-hail nets are the best way to mitigate the effects of hailstorms in the orchards. Apple trees covered with nets may exhibit a variety of vegetative and reproductive responses, inclusive of changes in tree vigour, cropping, sugar contents, and fruit colour. The present study was conducted to assess the effect of timing of installation and colour of anti-hail net on cropping and fruit quality in high-density apple orchard for two consecutive seasons (2021 and 2022). White and blue colour nets of size (9 m × 30 m) 80 GSM (square mesh with non-sliding threaded, leno weave, and < 30% shading factor) were installed at three different time intervals (15 days before estimated full bloom, at full bloom, and 15 days after full bloom) on apple cultivar 'Jeromine'. The installation at different time and colour of anti-hail nets significantly exhibit variability in cropping, fruit quality, and bio-chemical metrics. The significant highest cropping (fruit yield, productivity, and yield efficiency) and fruit biochemical parameters (total soluble solids) were recorded in T3C2 (15 days after full bloom + white colour anti-hail net) followed by T2C2 (installed at full bloom + white colour anti-hail net). Hence, white colour anti-hail nets installed 15 days after full bloom increased fruit production and improved quality in comparison to blue colour anti-hail net in apple under high-density plantations. [ABSTRACT FROM AUTHOR]

Effective nutrient management necessitates monitoring of nutrient requirement, extent and timing of nutrient supply during the fruit development. To achieve a good nutrient balance and its impact on fruit quality, study of nutrient dynamics is of utmost importance as it provides an intriguing stratagem to control tree nutrient status. The research aimed at investigating seasonal patterns of nutrient concentrations in leaves and fruits of apple (Malus × domestica Borkh.) cv Silver Spur on various clonal rootstocks (MM106, M4 and M9) during the year 2019–2020 and their impact on fruit quality. For this purpose collection of leaf and fruit samples commenced from one month after full bloom (May 15) until harvesting (September 18) at an interval of twenty one days and samples were evaluated for both macro and micro-nutrients {Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg) and Boron (B)} and quality characteristics. In general, concentration of N, P, K and B declined continuously in both leaf and fruit toward the end of fruit maturation, whereas leaf Ca and Mg augmented along the cycle, however fruit Ca and Mg increased up to first fruit development stage and then decreased again signifying nutrient dilution along growing season and its effect on fruit quality. With respect to rootstocks, semi-vigorous rootstock MM106 recorded higher values for leaf and fruit nutrient concentrations as compared to dwarf M9 and semi-dwarf M4 rootstocks specifying a significant effect of rootstocks on nutrient absorption. [ABSTRACT FROM AUTHOR]

The EFSA Panel on Plant Health performed a pest categorisation of Bailey's rust mite, Calepitrimerus baileyi Keifer (Acariformes: Eriophyidae), following the commodity risk assessment of Malus domestica plants from Türkiye performed by EFSA, in which C. baileyi was identified as a pest of possible concern to the European Union. This mite is not listed in Annex II of Commission Implementing Regulation (EU) 2019/2072. The eriophyid is known to occur in Africa, America, Asia, Europe (Greece and Serbia) and Oceania on Malus spp., which is the only confirmed host genus for C. baileyi. Plants for planting of Malus spp. are the main potential pathway for entry into the EU. However, plants for planting of the genus Malus Mill. are considered as high‐risk plants (EU 2018/2019) and therefore prohibited from entering the EU unless granted a country‐specific derogation. This is the case for the import of Malus spp. plants for planting from Serbia ((EU) 2020/1361 corrected by 2022/1309). Therefore, this derogation could provide a plausible entry pathway for C. baileyi into the EU. Climatic conditions and the ample availability of the host, Malus spp., in the EU are conducive for establishment, as proven by the occurrence of C. baileyi in Greece. However, the species is not reported as having an impact in Greece, despite reports of damage outside the EU. Measures to prevent further entry and spread of C. baileyi in the EU are available. C. baileyi satisfies all the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. However, uncertainties about the distribution of C. baileyi within the EU and its impact on apples in the EU are considered key and affect the confidence of conclusions for this categorisation. [ABSTRACT FROM AUTHOR]

The need for roughage in the animal nutrition industry has led to the search for various alternative roughage. In this context, as a result of the research, tree leaves have the potential to be considered as a nutritious and balanced forage source for animals. In this study, it was aimed to investigate the usability of apple (Malus domestica), apricot (Prunus armeniaca), cherry (Prunus avium), grape (Vitis vinifera), and umber mulberry (Morus rubra) leaves in ruminant nutrition. As a result of the research, nutritional contents of tree leaves (dry matter, crude protein, crude ash, crude oil, neutral detergent fiber, acid detergent fiber, acid detergent lignin, tannin), in vitro gas, carbon dioxide and methane gas production, in vitro gas post-production rumen fluid volatile fatty acid contents were found to be different from each other (P<0.05). In addition, although metabolic energy, organic matter digestion, digestible dry matter, dry matter consumption and relative feed values were found to be different in tree leaves (P<0.05), the highest values of these parameters were found in mulberry leaves. Metabolic energy (ME-J/kgDM) in grape, mulberry, apple, apricot and cherry is 9.24, 10.69, 10.07, 10.24, 9.33, organic matter digestibility (OMD-%) is 56.49, 58.98, 54.46, 57.34, and 58.31, respectively. has been detected. In the volatile fatty acids in the rumen fluid of the leaves after in vitro gas production; Total volatile fatty acid (TVFA-mmol/L) was defined as 69.16, 76.25, 66.04, 68.63, and 65.24, acetic acid (AA-mmol/L) was determined as 44.90, 48.52, 41.93, 46.82, and 43.62, respectively. As a result of our detailed studies, it has been determined that the leaves of various fruit trees stand out with their considerable nutritional content. The most important reason for the differences in the findings is that the nutritional content of tree leaves is different from differs. As a result of our comprehensive study, these nutritional content differences offer significant potential for using leaves of various fruit trees as a source of forage. [ABSTRACT FROM AUTHOR]

SUMMARY: Soluble sugar content is a key component in controlling fruit flavor, and its accumulation in fruit is largely determined by sugar metabolism and transportation. When the diurnal temperature range is greater, the fleshy fruits accumulated more soluble sugars and become more sweeter. However, the molecular mechanism underlying this response remains largely unknown. In this study, we verified that low‐temperature treatment promoted soluble sugar accumulation in apple fruit and found that this was due to the upregulation of the Tonoplast Sugar Transporter genes MdTST1/2. A combined strategy using assay for transposase‐accessible chromatin (ATAC) sequencing and gene expression and cis‐acting elements analyses, we identified two C‐repeat Binding Factors, MdCBF1 and MdCBF2, that were induced by low temperature and that might be upstream transcription factors of MdTST1/2. Further studies established that MdCBF1/2 could bind to the promoters of MdTST1/2 and activate their expression. Overexpression of MdCBF1 or MdCBF2 in apple calli and fruit significantly upregulated MdTST1/2 expression and increased the concentrations of glucose, fructose, and sucrose. Suppression of MdTST1 and/or MdTST2 in an MdCBF1/2‐overexpression background abolished the positive effect of MdCBF1/2 on sugar accumulation. In addition, simultaneous silencing of MdCBF1/2 downregulated MdTST1/2 expression and apple fruits failed to accumulate more sugars under low‐temperature conditions, indicating that MdCBF1/2‐mediated sugar accumulation was dependent on MdTST1/2 expression. Hence, we concluded that the MdCBF1/2‐MdTST1/2 module is crucial for sugar accumulation in apples in response to low temperatures. Our findings provide mechanistic components coordinating the relationship between low temperature and sugar accumulation as well as new avenues to improve fruit quality. Significance Statement: This study showed that low temperature induced the expression levels of the transcription factors genes MdCBF1/2 in apple, which could bind to the promoters of the tonoplast sugar transporter genes MdTST1/2 and activate their expression, leading to Glc, Fru, and Suc accumulation at high concentrations in the vacuoles. [ABSTRACT FROM AUTHOR]

Great diversity of shape, size, and skin color is observed among the fruits of different apple genotypes. These traits are critical for consumers and therefore interesting targets for breeding new apple varieties. However, they are difficult to phenotype and their genetic basis, especially for fruit shape and ground color, is largely unknown. We used the FruitPhenoBox to digitally phenotype 525 genotypes of the apple reference population (apple REFPOP) genotyped for 303,148 single nucleotide polymorphism (SNP) markers. From the apple images, 573 highly heritable features describing fruit shape and size as well as 17 highly heritable features for fruit skin color were extracted to explore genotype–phenotype relationships. Out of these features, seven principal components (PCs) and 16 features with the Pearson's correlation r < 0.75 (selected features) were chosen to carry out genome-wide association studies (GWAS) for fruit shape and size. Four PCs and eight selected features were used in GWAS for fruit skin color. In total, 69 SNPs scattered over all 17 apple chromosomes were significantly associated with round, conical, cylindrical, or symmetric fruit shapes and fruit size. Novel associations with major effect on round or conical fruit shapes and fruit size were identified on chromosomes 1 and 2. Additionally, 16 SNPs associated with PCs and selected features related to red overcolor as well as green and yellow ground color were found on eight chromosomes. The identified associations can be used to advance marker-assisted selection in apple fruit breeding to systematically select for desired fruit appearance. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae D65 isolated from the Malus asiatica naturally fermented liquid was used as the parental strain for mutation breeding of atmospheric and room temperature plasma (ARTP). The mutant strains with excellent characteristics were obtained through acid resistance test, esterase activity test, and fermentation test multi-step screening. The results showed that the specific activity of total esterase of D65-4D10 was 2428.30 U·g−1, and the ester content in the fermented Malus asiatica wine was 5710.75 ug·L−1, which was 20.69% and 41.64% higher than that of the parental strain, respectively. Moreover, the Malus asiatica wine fermented by D65-4D10 had stronger antioxidant capacity than the control, the highest score in sensory evaluation, and completed fermentation 24 h earlier than commercial yeast. After seven generations of continuous culture, the fermentation performance of D65-4D10 remained stable and had the potential to be applied to Malus asiatica wine fermentation. [ABSTRACT FROM AUTHOR]

Drying is a widely recognized process that reduces the need for storage and shipping weight, keeps free water out of the product, and prolongs its shelf life. An infrared dryer was designed to dry apples under different drying conditions. Apple slices of 6‐, 4‐, and 2‐mm thicknesses were dried at intensities 0.130, 0.225, and 0.341 W/cm2 and airflow 1.0, 0.5, and 1.5 m/s. The dehydrating period was prolonged with higher airflow and shortened with higher infrared intensity (IR). The shortest dehydrating period was verified by 190 min at 0.341 W/cm2, 0.5 m/s under 2 mm thickness. Increasing the sample thickness from 2 to 4 mm and then to 6 mm resulted in an 84% and 192% increase in drying time, respectively. Dehydrated apples had water activity values ranging from 0.30 to 0.40. The shrinkage ratio increased with an increase in infrared radiation intensity. However, it decreased with an increase in air velocity, while the rehydration ratio decreased with an increase in radiation intensity and increased with an increase in air velocity. Regarding total color change, apple slice thickness was a major factor. The effective diffusivities varied between 2.6 and 9.0 헑10−10 m2/s under different drying conditions. The dehydrating curves of apples were best described by the model developed by Midilli et al. [ABSTRACT FROM AUTHOR]