Apple Research Articles

Paecilomyces variotii extracts promote growth and alleviate nutrient deficiency symptoms in apple

It is essential to find environment-friendly agrochemicals to cope with the problems of nutrient imbalance, fruit quality decline, and physiological disorders during apple fruit production, which is beneficial for improving the quality and yield of apple. A natural extract from Paecilomyces variotii (ZNC), an endophytic fungus, has been used widely to enhance crop performance. However, an understanding of the mechanism underlying ZNC-triggered growth and alleviation of nutrient deficiency-associated symptoms in apples remains elusive. Here, the photosynthesis, leaf growth, and fruit quality were enhanced by adding ZNC. In addition, ZNC relieved nutrient deficiency-related symptoms promoted the differentiation of root morphology and vitality, and reduced the accumulation of osmoprotectants and reactive oxygen species, thereby promoting growth under normal and nutrient-deficient conditions. Finally, genome-wide RNA sequencing reveals the ZNC-regulated mechanisms involved in hormone and metal ion pathways. Our study reveals the role of ZNC in promoting growth and improving the quality of apple, providing a new direction for reducing the use of chemical fertilizers and pesticides.

Effects of enriched CO2, temperature, and irrigation on soil properties in greenhouse apple tree cultivation

The significant contributions of anthropogenic activity to global warming are evidenced by the increasing average atmospheric temperatures and CO2 concentration. To date, data on the impact of global warming on crops, particularly field-scale fruit growth and the soil environment, remain lacking. Therefore, we conducted a 4-year monitoring experiment on semi-closed apple tree populations cultivated under the present or near-future climate to assess the effects of atmospheric temperature and CO2 concentrations on soil moisture, temperature, and inorganic ion concentration. Apple saplings were grown in three independent environment-controlled greenhouses, namely greenhouses A (GH_A; control), B (GH_B; high-temperature), and C (GH_C; high-temperature and high CO2), representing climate modification experiments. The pH increased by 0.02, 0.20, and 0.12/year for GH_A, GH_B, and GH_C, respectively. In particular, GH_B (standard irrigation plot; STD) showed a significant pH increase of 0.25/year. The EC increased by 0.014 mS/cm/year for GH_A, decreased by -0.010 mS/cm/year for GH_B, and increased by 0.006 mS/cm/year for GH_C, showing no clear overall increasing or decreasing trend. The NO3 concentration increased by 1.2 mg/L/year for GH_A, decreased by 10.2 mg/L/year for GH_B and decreased by 0.7 mg/L/year for GH_C. The apparent activation energy (Ea) ranged from 85.3 to 214.4 (kJ/mol NH4+) and, regardless of watering treatment, GH_A > GH_B > GH_C. The values in STD plots were 1.4 to 1.7 times those in abundant irrigation plots. Using GH_A (STD) as a standard, the soil temperature dependence of the nitrification rate did not change overall at high or low air temperatures with increasing watering (Ea = 150.5 kJ/mol) or heating (Ea = 154.1 kJ/mol). The soil temperature dependence of the nitrification rate did not vary under heating and increased watering (Ea = 89.5 kJ/mol) or under heating, increased watering, and increased CO2 (Ea = 85.3 kJ/mol). This study provides novel insights into determining the environmental impacts of apple tree community soils under near-future climatic conditions.

Superfamily of glycolipid transfer proteins (GLTPs): Accelerated cell death 11-like (ACD11) enhances salt tolerance in apple

For adaptation to challenging environments, plants have evolved various response mechanisms, such as inducing the expression of many stress genes, thereby increasing the resistance. Accelerated cell death (ACD) genes have been widely studied in plant senescence and defense responses. However, there are few reports on the role of ACD genes in abiotic stresses in plants. In this experiment, ACD11 was successfully isolated from apples (Malus baccata) and found to be mainly expressed in apple fruits and roots. The response elements of abiotic stresses were also found in the promoter of MbACD11. Furthermore, MbACD11 expression was induced by various abiotic stresses, especially salt treatment. After overexpression of MbACD11 in apple seedlings, callis and Arabidopsis thaliana, all showed enhanced tolerance to salt stress. Under salt conditions, MbACD11-OE showed higher fresh weight and chlorophyll content compared to the WT. It also exhibited lower relative electrical conductivity, malondialdehyde (MDA) content, and reactive oxygen species (ROS) accumulation than the WT. The expression of salt stress-related genes was higher in MbACD11-OE apple seedlings than in WT. In salt stress condition, the apple MbACD11 gene reduced ROS accumulation and affected the expression of salt stress-related genes, hence enhancing tolerance.

The impact of 1-methylcyclopropene post-harvest treatment on the storability of the Ckifske zoloto and Dmiana apple varieties

As a result of the conducted research, it was established that the post-harvest treatment of apple fruits with Oberigpro, the active substance of which is 1-methylcyclopropene, helps to extend the duration of their storage in the conditions of an ordinary cooled atmosphere. In addition, the processed fruits had a 14-day post-storage shelf life during which they did not lose their quality, which allows producers to extend the duration of the sales period. The fruits of the varieties treated with 1-methylcyclopropene were harder than the control ones when removed from storage. After 60 days of storage, control apples had 21.8 N less pulp hardness than treated apples. During the 14 days of the shelf life, during which the apples were at a temperature of + 19 ºC, the hardness of their pulp in the version with treatment did not significantly decrease, unlike the version where 1-methylcyclopropene treatment was not applied. During the first month of storage, an increase in the content of soluble solids (TSS) was observed in the fruits of the Dmiana variety from the variant where post-harvest processing was carried out. Control fruits on the 150th day of storage contained 0.20% titratable acids, which is 0.10% less than those treated with 1-methylcyclopropene. On the 7th day of the expiration date, the acidity of Dmiana was 0.17 in the control and 0.25% in the fruits from the experimental variant, which is 0.20 and 0.28% less than that during storage, respectively. During the shelf life, fruit weight loss in both versions of the research increased, and on the 14th day, in the version treated with 1-methylcyclopropene, the Skifske Zoloto variety was 0.76% less, and the Dmiana variety was 1.59% less than in options without processing. With the growth of mass loss, the damage of the fruit withering increased, which negatively affected their appearance. On the 14th day of the post-harvest shelf life, Dmiana apples from the variant where 1-methylcyclopropene was not used were covered with an oily coating, and Skifske Zoloto 100% were affected by tan.

Natural variations in MdNAC18 exert major genetic effect on apple fruit harvest date by regulating ethylene biosynthesis genes.

Dissecting the genetic control of apple fruit harvest date (AFHD) into multiple Mendelian factors poses a significant challenge in modern genetics. Here, a quantitative trait locus (QTL) for AFHD was fine-mapped to the NAC transcription factor (TF) MdNAC18 within the interval defined by the overlap of QTLs Z03.5/Z03.6 and F03.2/F03.3. One direct target of MdNAC18 is the ethylene biosynthesis gene MdACO1. The single nucleotide polymorphisms (SNPs) SNP517 and SNP958 in the MdNAC18 coding sequence modulated activation of MdACO1 by MdNAC18. SNP1229 in the MdACO1 promoter destroyed the MdNAC18 binding site and thus abolished MdNAC18 binding. SNP517 and SNP958 also affected MdNAC18 activation of the TF gene MdARF5; MdARF5 activates the ethylene biosynthesis gene MdACS1. SNP517 and SNP958 in MdNAC18, SNP1229 and SNP769 (linked to InDel62) in MdACO1, and InDel162 in MdACS1 constituted a genetic variation network. The genetic effect of this network on AFHD was estimated as 60.3 d, accounting for 52.6% of the phenotype variation of the training population. The joint effects of these polymorphisms increased the accuracy of a genomics-assisted prediction (GAP) model for AFHD (r = 0.7125). Together, our results suggest that genetic variation in MdNAC18 affects AFHD by modulating ethylene biosynthesis and provide an optimized GAP model for apple breeding.

Cellulose Surface Nanoengineering for Visualizing Food Safety.

Food safety is vital to human health, necessitating the development of nondestructive, convenient, and highly sensitive methods for detecting harmful substances. This study integrates cellulose dissolution, aligned regeneration, in situ nanoparticle synthesis, and structural reconstitution to create flexible, transparent, customizable, and nanowrinkled cellulose/Ag nanoparticle membranes (NWCM-Ag). These three-dimensional nanowrinkled structures considerably improve the spatial-electromagnetic-coupling effect of metal nanoparticles on the membrane surface, providing a 2.3 × 108 enhancement factor for the surface-enhanced Raman scattering (SERS) effect for trace detection of pesticides in foods. Notably, the distribution of pesticides in the apple peel and pulp layers is visualized through Raman imaging, confirming that the pesticides penetrate the peel layer into the pulp layer (∼30 μm depth). Thus, the risk of pesticide ingestion from fruits cannot be avoided by simple washing other than peeling. This study provides a new idea for designing nanowrinkled structures and broadening cellulose utilization in food safety.

Effect of apple peel flour addition on physicochemical characteristics and fatty acid profile of reduced-fat mayonnaise

Introduction: Mayonnaise is popular throughout the world and contains various types of processed products. While reduced-fat mayonnaise (RFM) contains less than 50% oil, the drawback is the potential to reduce the physical quality of mayonnaise. The use of apple peel in the form of flour added to mayonnaise is predicted to enhance its physicochemical quality. Methods: The research comprised laboratory experiments using randomised design with four treatments and six repetitions. Apple peel flour was added to the treatments in the following proportions: 0% (RFA0), 1% (RFA1), 2% (RFA2), and 3% (RFA3). Analysis of variance (ANOVA) was used to obtain average values and standard deviations. Results: Addition of 3% apple peel flour to RFM showed highly significant effect (p≤0.01) on droplet size (2.15–9.49µm), viscosity (3965.00cP), colours L (71.93), a* (15.75), and b* (50.65), protein content (1.44%), and fat content (50.93%). It also produced an organoleptic quality that was acceptable to semi-trained panellists and fatty acid profiles containing various types of fatty acids. Conclusion: The use of 3% apple peel flour in RFM represented the best treatment, with potential for further improvement.

Application of sulfur-based products reduces Halyomorpha halys infestation and damage in pome fruit orchards.

The brown marmorated stink bug, Halyomorpha halys (Stål, 1855) (Hemiptera: Pentatomidae) is an invasive pest that causes economic damage on crops, decreasing fruit yield and quality. Conventional insecticides are frequently used to reduce infestations, but these are often with a limited residual effect, besides being costly and detrimental to nontarget organisms and the environment. In integrated pest management, novel strategies against H. halys are proposed, such as the use of alternative substances with an effect on insect behaviour and mobility. As one of the oldest multi-site fungicides applied against fungal pathogens and as an insecticide and acaricide to control scales and mites, sulfur is proposed here to reduce H. halys infestation in fruit orchards. Field experiments were performed to evaluate the effect of repeated wettable sulfur applications on H. halys in apple and pear orchards. Sulfur-induced plant phytotoxicity effects and quanti-qualitative parameters on apple fruits were also recorded. Halyomorpha halys infestation was significantly reduced in sulfur-treated compared to untreated pears and apples. Furthermore, sulfur sprays reduced fruit damage caused by H. halys. Besides, sulfur-mediated phytotoxicity such as symptoms on leaves and fruit drop were not observed. Fruit quality was not influenced by sulfur treatments. Wettable sulfur seems to be a promising formulation given the low phytotoxicity, considering the technical aspects for an effective use of sulfur-based products to counteract H. halys in pome fruit orchards. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Dynamics of degradation of residual amounts of propineb and its metabolite propyleneurea in apple fruits

The behavior of propineb and propylentiourea (PTU) in apples was studied in dynamics after treatment withAnthracol, water-dispersible granules (WDG) in 3 regions.The determination of pesticide residues was carried out according to developed and optimized methods.It was found that after 3-fold treatment with the fungicide propineb andPTUdecompose quickly and evenly in fruits in various regions of cultivation. 28 days after the last treatment, the content of the active substance of the drug and its metabolite are at a level below the corresponding of the maximum allowable level (MAL).At the time of harvesting, the studied substances in apples were not found in any of the climatic zones, as well as they were absent in the juice.Based on the data obtained on the decomposition of propineb in apple fruits, the nature of dissipation was established.The half-life ranged from 3 to 8 days.

Diplodia bulgarica, the cause of canker disease in apple (Malus × domestica) in Türkiye

The cultivated apple (Malus × domestica) is one of Türkiye’s most important economic crops. Over the growing seasons of 2020–2022, typical symptoms of branch cankers and scaling-off of the bark on apple trees were observed in the Eğirdir district of Isparta province. Botryosphaeriaceae fungi were consistently isolated from symptomatic branches. The fungal pathogen was identified as Diplodia bulgarica based on cultural and morphological characteristics and ITS region of DNA sequence data comparisons. Pathogenicity tests were performed on detached shoots by inoculating them with mycelial plugs. Diplodia bulgarica isolates caused necrotic lesions on Scarlet Spur apple detached shoots. To aid in the development of control strategies for this fungus, nine fungicides were examined in vitro for their antifungal effects against the pathogen at different concentrations. Chlorothalonil, tebuconazole, thiophanate-methyl, and fluazinam were the most efficient fungicides, with EC50 values were <1.0 µg/mL.

Postharvest Quality of ‘Keepsake’ Apple Fruit

Storage information regarding ‘Keepsake’ apple fruit is lacking. The objective of this research was to investigate the postharvest characteristics of ‘Keepsake’ apple (Malus ×domestica Borkh.), which is a parent of ‘Honeycrisp’. Apples were obtained from three orchards in Minnesota in 2022 and 2023, assessed for quality, and stored at 0 to 1 °C or 4 to 5 °C in air. Fruit were tested for firmness, soluble solids content (SSC), and titratable acidity (TA) for up to 6 months in storage. At harvest, fruit from different orchards differed in ground color, firmness, SSC, and titratable acidity. The starch pattern index did not differ among the orchards within a year, but it was greater during the 2023 harvest than during the 2022 harvest. Fruit firmness decreased less rapidly at 0 to 1 °C than at 4 to 5 °C. Changes in SSC with storage varied by orchard, storage temperature, and year. In 2022 to 2023, SSC changes were highly variable, remained the same during storage for fruit from one orchard, increased and then decreased for fruit from another orchard, increased after 1 month of storage, and then remained unchanged thereafter for fruit from the third orchard. In 2023 to 2024, SSC was generally unchanged during storage at 0 to 1 °C, and it increased slightly over time during storage at 4 to 5 °C. Titratable acidity decreased during storage, but there was no difference between storage temperatures. These findings demonstrate the difficulty determining when to harvest ‘Keepsake’ fruit because neither starch pattern index nor ground color is a reliable indicator of ripeness. Growers must rely on experience and fruit redness to determine when to harvest this late-season cultivar. To prolong fruit firmness, growers should store ‘Keepsake’ fruit at 0 to 1 °C rather than at 4 to 5 °C.

VmSom1 is essential for growth, development, maintenance of cell wall integrity and virulence in Valsa mali

Apple Valsa canker disease, caused by Valsa mali Miyabe et Yamada, severely endangers the healthy growth of apple trees. The Som1, located downstream of the cyclic AMP-dependent protein kinase A (cAMP-PKA) pathway, plays crucial roles in the growth, development, morphological differentiation, and virulence of filamentous fungi. In this study, we identify and functionally characterize VmSom1, a homolog of Som1, in Valsa mali. The VmSom1 gene is located on chromosome 12, encoding an 824 amino acid protein. Phylogenetic analysis reveals VmSom1 as a fungal Som1 homolog. The VmSom1 deletion mutants exhibit slower growth rates and fail to produce pycnidia. Additionally, their hyphal growth is significantly inhibited on media containing Calcofluor White, Congo Red, NaCl, and sorbitol. The growth rate of VmSom1 deletion mutants is reduced on maltose, lactose, sucrose and fructose media but increases on glucose medium. Moreover, the mycelial growth rate of the VmSom1 deletion mutant is significantly lower than that of the wild-type strain in peptone, NH4SO4, NaNO3, and no nitrogen. Notably, the distances between the septa increase, and chitin concentration shifts to the hyphal tip in the VmSom1 deletion mutant. Furthermore, compared with the wild-type strain, the VmSom1 deletion mutant exhibits fewer diseased spots on apple fruit and branches. Overall, our findings demonstrate that VmSom1 is involved in regulating the growth and development, colony surface hydrophobicity, osmotic stress, cell wall integrity maintenance, carbon and nitrogen source utilization, septa formation, and virulence of V. mali.

Complete genome sequence of Erwinia pyrifoliae strain YKB12327, isolated from an apple tree in Korea

Complete genome sequence of Erwinia pyrifoliae strain YKB12327, isolated from an apple tree in Korea

Assessing and Quantifying the Carbon, Nitrogen, and Enzyme Dynamics Effects of Inter-row Cover Cropping on Soils and Apple Tree Development in Orchards

Cover crops between rows in orchards can improve the development of soil resources and increase agricultural productivity. However, there have been few reports of cover crops that can act as a “green manure” in apple orchards across arid and semiarid zones. This study investigated the effects of planting interrow vegetation on soil properties and apple tree performance during a 32-month experiment. There were six treatments: clean cultivation as a control; natural grass planting; planting with ryegrass; planting with alfalfa; planting with tall fescue; and planting with villous wild pea cover crops. The treatments primarily affected the 0- to 20-cm surface soil layer. Soil carbon, nitrogen, and enzyme levels initially decreased (during the first 12–24 months); then, they increased (24–32 months). The cover crops significantly increased nutrient contents (soluble organic carbon, microbial carbon and nitrogen, alkaline dissolved nitrogen, nitrate nitrogen, and ammonium nitrogen) in the 0- to 20-cm soil layer by more than 19.6% and increased the related enzyme activities by more than 25.2%. The alfalfa and wild pea alleys had a stronger effect on the soil environment than the control, natural grass, ryegrass, and tall fescue alley treatments; however, after 32 months, the alfalfa treatment inhibited fruit tree growth and development. This was unexpected because alfalfa seemed to have a positive effect on soil fertility characteristics. Under local ecological conditions, villous wild pea had the greatest effect on apple orchard productivity and significantly increased short branching by 15.9%, fruit weight per fruit by 12.6%, yield per plant by 8.6%, and soluble sugar content by 10.5% compared with clean cultivation. The correlation analysis showed that there were significant or highly significant positive correlations between fruit tree performance and soil carbon, nitrogen, and enzyme activity levels as the soil layer depth increased. Therefore, under local ecological conditions, cover crops have a greater effect on orchard surface soil fertility than on deeper soils, and intercropping with villous wild pea potentially produces the greatest improvement in apple orchard productivity.

Masking of bitterness in lettuce (Lactuca sativa L.) by apple juice (Malus domestica Borkh.) in green smoothies - A pilot consumer study

While fruit smoothies are widely used to enhance fruit consumption, vegetable based green smoothies have not yet been systematically analyzed for consumer acceptance. Vegetable based green smoothies are often neglected due to their bitter and unpleasant taste or are masked with sweet fruits. This study investigates consumers' liking of 3 different smoothies with equal amounts of bitter lettuce and apple, but different portions of sweet apple juice, resulting in a decreasing bitter-compound-to-sugar ratio. Liking (9-point scales) of odor and taste, flavor perception (check-all-that-apply) and texture (just-about-right scale) were evaluated by 67 consumers. In the sweetest smoothie the descriptor ‘bitter’ was chosen almost 4 times less frequently than in the smoothie with the lowest sugar concentrations (medium effect size; Cohens D: 0.569). Detailed knowledge of bitter masking thresholds may help to balance between bitter masking and limited use of highly caloric ingredients in healthy green smoothies.

Characterization of Fungal Species Isolated from Cankered Apple Barks Demonstrates the Alternaria alternata Causing Apple Canker Disease.

Apple canker disease, also named as apple Valsa canker, is one of the most destructive diseases for apples (Malus domestica Borkh.). Cytospora/Valsa spp. are the dominant causal agent of this disease, but many studies have revealed that fungi from some other genus can also cause typical apple canker symptoms. In this study, we performed fungal pathogen isolation from cankered 'Fuji' apple barks. Six representative morphologically different fungi (Strain 1-6) were further subjected to ITS sequencing and evolutionary analysis. Molecular identification results revealed that Strains 1-6 are Cytospora mali, Fusarium cf. solani, Alternaria alternata, C. mali, Diplodia seriata and F. proliferatum, respectively. All these fungi have been reported to be causal agents of apple diseases. By inoculating fungal plugs onto trunks of 'Fuji' apple trees, the pathogenicity of the six fungi were accessed. Only the inoculations of the two C. mali strains (Strain 1 and Strain 4) and the A. alternata strain (Strain 3) resulted in typical apple canker symptoms in trunks. It is worth noting that Strain 1 caused much more severe canker symptoms and higher pathogenicity incidence than the other two fungi. A. alternata has been identified as a pathogen causing diseases on apple fruits and leaves. By further assessing its pathogenicity on apple fruits and leaves, we verified that it can also cause typical fruit rot and leaf spot symptoms. To the best of our knowledge, this is the first report on apple canker disease caused by A. alternata in China. Our present study can provide a theoretical foundation for the prevention and control of apple canker disease.

Raman spectroscopy as a tool for characterisation of quality parameters in Norwegian grown apples during ripening

This study shows for the first time the feasibility of Raman spectroscopy as a non-destructive method to follow the ripening process of apple fruits. Two different varieties of apples were studied: ‘Aroma’ and ‘Elstar’. By visual inspection, Raman spectra showed that the starch content was higher in ‘Elstar’ apples compared to ‘Aroma’. The degradation of starch over time could be detected in the Raman spectra, indicating that the method can be used to monitor the ripening process. The ripeness markers starch index, soluble solids content (SSC), and the sugars glucose, fructose and sucrose were determined with traditional destructive methods. Cross validated calibration models based on Raman spectroscopy were obtained for all quality parameters, and test set validation offered good results, with R2 in the range 0.4–0.86 for ‘Aroma’ and 0.4–0.95 for ‘Elstar’, respectively. The regression coefficients showed that the calibrations relied on Raman bands associated with starch and different sugars. The results suggest that Raman spectroscopy in the future could be used to determine the optimal time of harvesting and to sort apples into different degrees of ripeness.

Нано-, био- и когнитивные технологии в производстве сидров и плодовой алкогольной продукции

Abstract. A brief overview of nano-, bio- and cognitive technologies in the beverage industry is presented. When developing products in the «science – production – market» system, it is currently necessary to focus on consumer preferences. The totality of the values of a manufactured product is determined by its consumer properties, commercial attractiveness, and is perceived as one whole. This must be taken into account when designing new high-quality Russian-made products. A brief overview of nano-, bio- and cognitive technologies in the beverage industry is provided with the aim of developing a cider production business plan model based on improved biotechnological techniques for the production of fermented apple wort. Objects of research: apple must from various varieties of apple fruits of domestic and foreign selection; enzyme preparations (SQzyme PCL, Grainzyme NL and Fructozym® P); yeast strains (OIC Fruit, Fruit Turbo, Combi and RV 100), bentonites (Vinobent, Bentovin, Bentovinum Gold, Bentostab, Apro-fine bent G, Apro-fine bent UF, Perdomini, etc. As a result, the feasibility of using enzyme preparations was shown (the most effective was SQzyme PCL with pectolytic action). The highest tasting rating was given to a sample of cider fermented with the Combi yeast strain (Saccharomyces cerevisiae and Oenococcus oeni), which was characterized by a bright, complex aroma and a full, rounded taste. The use of composites based on bentonites, proteins, tannins) for clarification and stabilization of ciders made it possible to obtain drinks of a light straw color while maintaining a bright aroma, and to increase their bottling resistance from 2 to 8 months. A model of a business plan for a cider production operating on a full cycle is proposed, with the possibility of receiving tourists, excursions to the apple orchard, production, tasting rooms and sales of products. Research was conducted to justify and select technological aids and yeast strains to improve biotechnological methods for the production of traditional ciders. Keywords: cognitive technologies, nanotechnology, biotechnology, yeast, technological aids Financing source: The research is carried out with the financial support of the Kuban Science Foundation in the framework of the scientific project № MFI-20.1/100.

Comparative biochemical and physiological responses to the virus-induced mosaic disease in apple (Malus domestica)

Comparative biochemical and physiological responses to the virus-induced mosaic disease in apple (Malus domestica)

A novel amine- functionalized apple peel biocarbon and beta vulgaris cellulosic fiber-based rigid vinyl-based microwave shielding composite

A novel amine- functionalized apple peel biocarbon and beta vulgaris cellulosic fiber-based rigid vinyl-based microwave shielding composite