This research represents the first comprehensive biochemical analysis of mature fruits from apple trees of the Chloromeles section, specifically examining Malus coronaria, Malus ioensis, Malus × platycarpa and Malus × soulardii. The experimental investigations revealed distinctive compositional characteristics in lipids, carbohydrates, flavonoids, and chlorophylls that markedly differentiate these species from other representatives of the genus Malus. Specifically, our research revealed the absence of procyanidin B1 and a high content of chlorogenic acid, accompanied by remarkably low quantities of cinnamic acid and its derivatives. Linoleic acid represented approximately 50% of the total fatty acid profile, which is substantially lower compared to the lipid content commonly observed in domesticated apple varieties. Conversely, the linolenic acid concentration was significantly higher. Fructose levels in fruit tissues of the Chloromeles section ranged from 15% in M. ioensis to 50% in M. coronaria, the section's largest fruiting species. Additionally, the analysis revealed the presence of transport sugars and highly etherified protopectins. Unlike other Malus, the Chloromeles section mature fruits exhibited high chlorophyll and low carotenoid contents. These pigments were present in both the peel and pulp tissues. The observed composition, including elevated transport sugar and protopectin levels, is typically associated with fruits at early ripening stages. This may contribute to the suboptimal flavor development, despite the presence of a relatively high total soluble sugar content.

Apple (Malus domestica) is a woody fruit tree belonging to the Rosaceae family, genus Malus. It has been widely reported that MYB transcription factors are critical regulators for the red color of apple peel by activating the expression of anthocyanin biogenesis genes. However, it is still not clear what the molecular mechanism for the yellow color of apple peel is. In order to investigate key genes and metabolites responsible for yellow coloration of apple peel, three strains of apples, “Venus Gold (Ype)” with yellow peel, “Yanfu8 (Mpe)” with medium red peel, and “Red love” with dark red peel, were selected in this study. Transcriptomic and metabolomic profiles were obtained for the peels of the three apple strains. After analyzing the transcriptomic profiles and being verified with qRT-PCR experiments, our results suggest that LAR1 is a critical gene for the yellow color of Ype peel. Analysis of metabolomic profiles revealed that the abundances of catechin and epicatechin in Ype peel were higher than those in Rpe, indicating an important reason for the yellow color of Ype peel. Furthermore, when comparing volatile metabolites from Ype, Mpe, and Rpe, hundreds of volatile metabolites show significantly different abundances, suggesting that apples with different peel colors have different odors. Our results uncover a novel metabolic mechanism for yellow coloration, where high expression of LAR1 promotes accumulation of catechin and epicatechin, providing the first integrated transcriptomic and metabolomic evidence for this pathway in apple peel.

A comprehensive analysis of the variability of morphological and biological characteristics of the diasporas of East Asian representatives of the Maleae Small (Rosaceae) tribe, introduced and cultivated in the conditions of the subarctic region, has been carried out at the Dengrological Garden named after I.M. Straronovich. The research has covered such parameters as the weight of 1,000 fruits and 1,000 seeds, the percentage of seeds yielding from fruits, and the seed quality (viability). The coefficients of variation have ranged from 8.4 to 37.2 % for the weight of 1,000 fruits, from 10.5 to 41.9 % for the weight of 1,000 seeds, from 14.9 to 98.1 % for the percentage of seed yield from fruits and from 13.7 to 71 % for quality/viability. The analysis of correlations has revealed the complex nature of intertrait relationships and significant phenotypic variability. Thus, the plum-leaved apple trea (Malus prunifolia (Willd.)) has shown a high negative correlation between fruit weight and seed yield (r = –0.51, p < 0.05). In the Siberian crab apple tree (M. baccata (L.) Borkh.) from the natural range, statistically significant positive correlations have been established between the weight of 1,000 fruits, the weight of 1,000 seeds and viability (r = 0.61–0.73, p < 0.05), whereas in specimens from the secondary range these relationships are absent or insignificant. For the crab apple tree samples from the Perm Botanical Garden, a stable positive correlation has been established between seed weight and their quality (r = 0.72–0.84, p < 0.05). Overall, the weight of 1,000 fruits and the percentage of seed yield from fruits show predominantly week or negative correlations (r = –0.59–0.38). The results obtained emphasize the necessity for a comprehensive and direct assessment of the quality of seed material when performing introduction and breeding activities. The practical significance of this research lies in ensuring effective selection and forecasting of the productivity of introduced species, which contributes to the formation of stable and productive populations of woody plants in the climatic conditions of the subarctic region.

Recently, crabapples have attracted increasing attention due to the accumulation of antioxidants in vegetative and generative organs. This study aimed to determine the antioxidant content of fruits and leaves of representatives of the genus Malus spp. In addition, the total content of vitamin C, hydroxycinnamic acids, chalcones and anthocyanins in the study samples were evaluated. Total antioxidant activity was found in the fruits ranging from (26.88%) to (83.62%), in the leaves from 76.58 to 83.68%. Ascorbic acid content ranged from 21.7 to 31.6 mg.100 g-1 in the fruits, and from 103.8 to 153.7 mg.100 g-1 in the leaves. Content of hydroxycinnamic acids was of 0.13–0.45, and 1.4–2.69% in the fruits and leaves, respectively. Contents of chalcones were determined in fruits from 34.6 to 72.3 mg.100 g-1, in the leaves from 71,3 to196,26 mg.100 g-1, and anthocyanins in fruits from 53.7 to 144.5 mg.100 g-1, in the leaves ranged 71.3 to 196.2 mg.100 g-1, respectively. Also, the study determined the high significant correlation between antioxidants and phenolic compounds in the fruits (r2 = 0.76, P < 0.01) and in the leaves (r2 = 0.96, P < 0.03). A relationship was found between the accumulation of hydroxycinnamic acids and chalcones (r2 = 0.9, P < 0.02). This study indicates that small-fruited apples, especially red apples, have great potential as a health food riched in phenolic compounds with high antioxidant activity, as well as antiproliferative activity against cancer cells by large literature review. Based on the study, we can identify donors with valuable biological composition to improve the efficiency of breeding and create new apple varieties with a high content of vitamins, biologically active substances and other components necessary for the balance of useful nutrition.

High-quality green gardens can markedly enhance the quality of life and mental well-being of their users. However, health and lifestyle constraints make it difficult for people to enjoy urban gardens, and traditional methods struggle to offer the high-fidelity experiences they need. This study introduces a 3D scene reconstruction and rendering strategy based on implicit neural representation through the efficient and removable neural radiation fields model (NeRF-RE). Leveraging neural radiance fields (NeRF), the model incorporates a multi-resolution hash grid and proposal network to improve training efficiency and modeling accuracy, while integrating a segment-anything model to safeguard public privacy. Take the crabapple tree, extensively utilized in urban garden design across temperate regions of the Northern Hemisphere. A dataset comprising 660 images of crabapple trees exhibiting three distinct geometric forms is collected to assess the NeRF-RE model’s performance. The results demonstrated that the ‘harvest gold’ crabapple scene had the highest reconstruction accuracy, with PSNR, LPIPS and SSIM of 24.80 dB, 0.34 and 0.74, respectively. Compared to the Mip-NeRF 360 model, the NeRF-RE model not only showed an up to 21-fold increase in training efficiency for three types of crabapple trees, but also exhibited a less pronounced impact of dataset size on reconstruction accuracy. This study reconstructs real scenes with high fidelity using virtual reality technology. It not only facilitates people’s personal enjoyment of the beauty of natural gardens at home, but also makes certain contributions to the publicity and promotion of urban landscapes.

The integration of HS-SPME-GC/MS and UPLC-MS/MS techniques enabled the profiling of volatile organic compounds (VOCs) and amino acids (AAs) in 18 crabapple flower cultivars, facilitating the development of a novel VOC–AA model. Among the 51 identified VOCs, benzyl alcohol, benzaldehyde, and ethyl benzoate were predominant, categorizing cultivars into fruit-almond, fruit-sweet, and mixed types. The amino acids, namely glutamic acid (Glu), asparagine (Asn), aspartic acid (Asp), serine (Ser), and alanine (Ala) constituted 83.6% of the total AAs identified. Notably, specific amino acids showed positive correlations with key VOCs, suggesting a metabolic regulatory mechanism. The Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) model, when combined with volatile organic compounds (VOCs) and amino acid profiles, enabled more effective aroma type classification, providing a robust foundation for further studies on aroma mechanisms and targeted breeding.

The aim of the article is show the response to biotic stress (in particular, fungal attack) using hydroxamic acid derivatives in the example of fruit plants. Two new compounds were synthesized at the Institute of Organic Chemistry of the NAS of Ukraine: compound No. 2 (C14H20N2O4S) and No. 3 (C14H20N2O4), compound No. 1 C12H16N2O4S was used as a control. Synthesized compounds No. 2 and No. 3 were tested in vivo on prototypes, representatives of the genus Malus Mill. are damaged by pathogenic fungi. An accumulation in the content of secondary metabolites after treatment with the compound C12H16N2O4S and a decrease after treatment with the compounds C14H20N2O4S and C14H20N2O4 was noted in the sites of hydroxamic acid application. Since substances of the flavonoid series are phytoalexins, the lesion of the plant by cytosporosis and powdery mildew leads to an increase in the content of flavonoids. Compounds No. 2 and No. 3 inhibit the development of pathogenic fungi, so there is no need for additional synthesis of flavonoids, compound № 1 does not have pronounced fungicidal properties. Considering the primary the primary results, we can judge further prospects for the study and use of synthesized hydroxamic acids (C14H20N2O4S) and (C14H20N2O4).

ABSTRACTCrab apples have high nutritional and economic value. The core removal process plays an important role in making crab apples into dried fruit that can be easily stored and transported. By finite element simulation of the factors affecting the performance of the core removal process, the core removal force and energy consumption can be effectively reduced. The density of crab apples was determined to be 0.859 g cm−3 using the drainage method. The quasi‐static compression test revealed that the modulus of elasticity, yield strength, and damage strength of crab apples were 2.93, 0.1329, and 0.7369 MPa, respectively. Based on the core removal model, one‐factor simulations of the core removal process were explored. The optimized core removal parameters for crab apples were a cutter wall thickness of 0.8 mm, a flat blade cutter, and a core removal speed of 150 mm s−1. The results showed that the cutting force and energy consumption were reduced by 48.55% and 34.08%, respectively. The model and optimized tool parameters provide valuable insights for the design and development of crab apple core removal equipment and the mass production of multi‐cored fruits.

The edible value of crabapple flowers remains unreported. In this study, the flower buds of three crabapple cultivars with different flower colors, Malus ‘Royalty’ (purple-red), ‘May’s Delight’ (pink), and ‘Snowdrift’ (white), were processed via hot-air drying at different temperatures and durations. The results showed that the sensory scores of ‘Royalty’ (4 h at 50 °C or 6 h at 40 °C), ‘Snowdrift’ (5 h at 50 °C), and ‘May’s Delight’ (4 h at 60 °C or 6 h at 50 °C) were higher (score > 90 points). The contents of phloridzin, total flavonoids (TFC), and total free amino acids (TFAC) in ‘May’s Delight’ under 50 or 60 °C were significantly higher than in other treatments. The differences in functional constituents among the different treatments of ‘Royalty’ were the smallest (C.V < 7%). The influences (C.Vk > 35%) of cultivar and drying temperature on the phlorizin content (PC) and TFAC were significantly higher than those of other treatments. The PC maintained the highest stability (C.Vk < 10%) under different temperatures and durations. The value of color parameter a* of dry flowers was significantly positively correlated with TFC, PC, and TFAC, and the total score of the sensory evaluation was positively correlated with the TFC. Based on functional constituents and sensory evaluation, ‘May’s Delight’ with air-drying at 50 °C for 6 h was the best option for crabapple flower tea.

Many specialized metabolites found in plants have significant potential for developing environmentally friendly weed management solutions. This review focuses on the phytotoxic effects of volatile terpenes and phenolic compounds, particularly nepetalactone, an iridoid monoterpenoid from Nepeta species, and phloretin, a dihydrochalcone predominantly found in the genus Malus. We highlight current findings on their herbicidal effects, including morphological, physiological, and biochemical responses in target plants. These results underscore their potential for developing sustainable herbicides that could control weeds with minimal environmental impact. We also discuss their soil persistence and methods to enhance their solubility, chemical stability, and bioavailability. Additionally, the possible effects on non-target organisms, such as pollinators, non-pollinating insects, and soil microbiota, are considered. However, further research and a deeper understanding of their long-term ecological impact, along with a resistance development risk assessment, is essential for the potential development of bioherbicides that could be applied in sustainable weed management practices.

To enhance the breeding of new scab-resistant apple cultivars, a comprehensive understanding of the mechanisms governing major scab resistance genes is essential. Rvi12_Cd5 was previously identified as the best candidate gene for the Rvi12 scab resistance of the crab apple "Hansen's baccata #2" by gene prediction and in silico analysis. In the present study, Rvi12_Cd5 was used to transform the scab-susceptible apple cultivar "Gala Galaxy." Two constructs were prepared: the first carrying Rvi12_Cd5 under the control of a 35S promoter and E9 terminator, and the second carrying Rvi12_Cd5 under the control of its native promoter and terminator. All the transgenic lines were analyzed for T-DNA integration, copy number, and expression of Rvi12_Cd5 and phenotypically evaluated for scab resistance. The "Gala Galaxy" lines carrying the 35S promoter expressed Rvi12_Cd5 at a high level, showing partial to high resistance against a mixed inoculum of Venturia inaequalis, with symptoms ranging from class 0 to 3b on the Chevalier scale. The transgenic lines carrying the native promoter showed a lower expression of Rvi12_Cd5 compared with the 35S lines. Nevertheless, the low expression was sufficient to induce a resistance level comparable to that of the transgenic lines carrying the 35S promoter. These results indicate that Rvi12_Cd5 confers scab resistance to a susceptible apple cultivar and that even a low level of gene transcript can trigger a plant response to V.inaequalis infection. After HcrVf2 and Vr2-C, Rvi12_Cd5 is the third major apple scab resistance gene being functionally proven.

Panax ginseng (Asian ginseng) and Panax quinquefolius (American ginseng) are two important species of genus Panax used commercially in China. The main species of Colletotrichum on P. ginseng have been previously investigated, but Colletotrichum on P. quinquefolius has not been verified in China. In June 2020, August 2021 and September 2022, leaf spots on P. quinquefolius were found in Jilin Province, northeastern China. Eighty Colletotrichum strains were isolated from the diseased leaves and were identified as Colletotrichum panacicola based on morphology and molecular characterization. After inoculation of these strains on detached or attached American ginseng leaves, leaf spots developed after 4 days on detached leaves and after 6 days on attached leaves. A fungus with the same morphology and spores as the inoculated strain was re-isolated from the lesions. This is the first report of leaf spot disease of P. quinquefolius caused by C. panacicola in northeastern China. We also tested this pathogen on 13 other plants and found that it can cause severe symptoms on apricot and crab apple, both members of Rosaceae. This study confirms a new location and additional host range of this fungus and highlights that it is a potential threat to P. quinquefolius cultivation in China.

We investigated the behavior of stable Cs+ ions contained in droplets applied directly on the leaf surfaces of plumleaf crab apple trees (2-3years old Malus domestica 'Alps Otome') at three different fruit growing stages: before bearing fruit, early fruit development and late fruit development stages. Most of the Cs was rapidly transferred from the leaf surfaces into the applied leaves after application, and then gradually transferred to the fruit through the branches. The mean proportion of Cs transferred to fruit by harvest time ranged from 11 to 30% not directly depending on the fruit growing stages. Cs absorption from leaf surfaces was faster at early and late fruit development stages than before bearing fruit stage, and Cs transfer from leaf surfaces to the fruit was faster as the fruit growing stage progressed. To describe the transfer of Cs, we constructed a compartment model using the datasets of obtained for each fruit growing stage. However, it did not well reproduce the measured values, showing that further studies are necessary.

ABSTRACTAn S‐RNase‐based gametophytic self‐incompatibility (GSI) system, a mechanism that forces outbreeding by preventing self‐fertilization, characterizes the genus Malus. Knowledge of the self‐incompatibility (S) genotypes of apple cultivars is crucial for choosing pollen donors for fruit production and breeding. Even though the S‐allele of most commercial apple cultivars has already been identified, limited information is available about the S‐allele diversity within local germplasm collections. In this study, 67 S‐allele combinations of local apple accessions were identified. The allele S3 was the most common among local apple accessions followed by S1 and S7. The main aim of this study is to provide new information on cultivar compatibility, and these results will be used to set up new parent selection in apple breeding programmes as well as pollinator selection for the commercial orchard.

Pollen represents a reward for pollinators and is a key element in plant-insect interactions, especially in apples, which are entomophilous species and require cross-pollination to produce economically valuable yields. The aim of this study was to analyze the chemical content of the pollen in 11 apple cultivars ('Red Aroma', 'Discovery', 'Summerred', 'Rubinstep', 'Elstar', 'Dolgo', 'Professor Sprenger', 'Asfari', 'Eden', 'Fryd' and 'Katja') grown in Norway and try to establish a relationship between them and insect attractiveness. In the applied chemical analysis, 7 sugars and sugar alcohols, 4 organic acids, 65 phenolic compounds, 18 hydroxycinnamic acid amides (phenylamides), a large number of polypeptides with a molecular weight of 300 kDa to <6.5 kDa, lipids, carotenoids, starch, pectin and cellulose were determined. The crab apples 'Dolgo' and 'Professor Sprenger', which are used as pollenizers in commercial orchards, had the highest level of sucrose, total polyphenol content (prevent oxidative damages in insects), antioxidant capacity, hydroxybenzoic acids and derivatives, quercetin and derivatives, dihyrochalcone, epicatechin, putrescine derivates, and proteins with molecular weight 66-95 kDa and >95 kDa, which made them interesting for insect pollenizers. Only the pollen of the crab apples contained quercetin-3-O-(2″-O-malonyl)-hexoside, which can be used as a marker for the apple species Malus sylvestris (L.) Mill. Apple floral pollen is a rich source of bioactive components and can be used to prevent and/or cure diseases or can be included in diets as a "superfood".

Columnar and crab apple breeding in Latvia

The study aimed to conduct a comparative assessment of representatives of the genus Malus based on morphological traits, biological characteristics, physiological mechanisms of resistance to fungal pathogens, ornamental value, and significance within the frameworks of horticulture, landscape forestry, and shelterbelt afforestation. Employing an integrative approach, the research examined the morphological traits and biological characteristics of domestic apple, European wild apple, Siberian crab apple, hybrid crab apple, and plum-leaved apple. Comparative analysis was carried out to evaluate the susceptibility and resistance of these species to scab pathogens and other diseases. The findings indicated that the domestic apple is characterised by large fruit size, with an average fruit mass of no less than 150 g. In contrast, the average fruit mass for Siberian crab apple, cherry crab apple, and hybrid crab apple does not exceed 0.7 g, 1.8 g, and 3.2 g, respectively. The authors have developed an integrated scale for the comparative evaluation of Malus species (or crab apple varieties) based on overall ornamental value. This scale included five criteria: crown appearance, leaf aesthetics, floral attractiveness, fruit visual appeal, and resistance to apple scab. For the first time, fruits of different Malus species have been analysed for seed productivity. Among these, crab apple varieties, particularly the European wild apple and the plumleaved apple, were identified as having the highest average number of seeds per fruit – 10 and 8 seeds, respectively. It was also shown that the seeds of the wild apple are relatively large, with the 100-seed weight exceeding 3.9 g. The study highlighted findings that confirm the ornamental value of certain Malus species, notably the Siberian crab apple and the hybrid crab apple, which received the highest overall ornamental scores of 4.5 and 5. This contrasts with the European wild apple, cherry apple, and domestic apple, which scored lower for ornamental attributes (3.2-3.9). It was noted that crab crab apple species such as Malus sylvestris (L.) Mill. and Malus baccata (L.) Borkh. are wellsuited for use in the creation of forest-park landscapes. Under the conditions of the Northern Forest-Steppe of Ukraine, Malus species were differentiated by their resistance to the scab pathogen (Venturia inaequalis Cooke). The results established that domestic apple (cultivar Dozhnytsia), hybrid crab apple, and plum-leaved apple exhibited high resistance to this pathogen, which affects both foliage and fruit. The practical application of these findings lies in enriching the informational database on Malus species with updated data, enabling their utilisation in various thematic studies

Background. Currently, the use of an interdisciplinary approach based on a combination of traditional introduction methods and clonal micropropagation techniques makes it possible to solve one of the key problems of introduction – the establishment of bioresource collections consisting of selected plant accessions with valuable agronomic traits and resistance to unfavorable urban environments. Materials and methods. A plant introduction study resulted in identifying seven specimens of Malus niedzwetzkyana Dieck with resilience to urban environments, high rate of crown development, and longevity. They served as source material for the development of a clonal propagation protocol and in vitro preservation of selected genotypes of this species. Results. It was shown for M. niedzwetzkyana that the most favorable time for taking its plant material for introduction into in vitro culture is the beginning of the active growth of vegetative shoots after flowering. The most optimal sterilization technique for such plant material was a stepwise regime using alcohol, sodium hypochlorite, and silver nitrate: it provided from 50 to 70% of sterile explants and the maximum percentage of meristem proliferation. Combining 0.8 mg/L of benzylaminopurine (BAP) with 0.14 mg/L of indole-3-butyric acid (IBA) at the stage of microclonal propagation ensured a significant increase of the reproduction coefficient (on average up to 5.3 ± 0.7) and an improvement in morphometric parameters of microshoots; the maximum frequency of shoot proliferation was 100%. The yield of shoots adapted to ex vitro conditions was 90%. Conclusion. The developed clonal micropropagation protocol made it possible to introduce selected M. niedzwetzkyana forms into in vitro culture and reproduce them in order to set up a resource base for further fundamental and applied research into the system of the genus Malus Mill.

The impact of green roofs’ composition on its overall life cycle

ABSTRACT Crab apple (Malus sylvestris (L.) Mill.) is native to Central Europe and successfully commercially grown in Indonesia. Management practices that increase biodiversity in agroecosystems are essential for mediating the negative impacts of intensive agriculture. This study aims to compare arthropod abundance and diversity between grass ground cover and Hydrangea intercropping in crab apple orchards and assess their impact on arthropod functional groups providing ecosystem services. In this study, arthropods were sampled using three types of traps, i.e. pitfall trap, yellow sticky trap, and pan trap. Arthropod specimens were identified by order and family, then categorised by their ecological role: detritivore, omnivore, herbivore, the natural enemy (predator and parasitoid), and pollinator. Our study collected 164 families belonging to the five examined functional groups. We found that the family composition of arthropods was significantly different between Hydrangea intercropping and grass ground cover in crab apple orchards. Grass ground cover supports the increase of herbivore and natural enemy populations and it’s related to enhancing biological control. In addition, Hydrangea intercropping increases pollinator species richness and contributes to pollination services. Pest management in crab apple orchards may benefit from a combination of grass ground cover to encourage natural enemies and Hydrangea intercropping to increase pollinators.