Search Results (26)

Plant growth-promoting (PGP) bacteria are beneficial microbes that can help plants mitigate various biotic and abiotic stresses through different PGP functions. Flavins (FLs) are involved in flavoprotein-mediated reactions essential for plant metabolism and could act as PGP molecules. The aim of this study was to isolate and characterize potential FLs secreting bacteria from apple (Malus domestica [Suckow] Borkh) roots based on their fluorescence and to evaluate their PGP properties, including FLs secretion. A total of 26 bacteria with increased fluorescence in liquid culture were isolated from the apple roots. Based on 16S rRNA sequencing analysis, 11 genetically different strains mostly from Burkholderia and Rhizobia spp. were identified. All isolates secreted considerable amounts of riboflavin. In vitro plant assays showed that under nitrogen (N) limitation, inoculated alfalfa (Medicago sativa) plants yielded at least 25% more dry mass than non-inoculated plants, and inoculation with AK7 and FL112 enriched plant tissue N content compared to non-inoculated plants. This improved N acquisition was not linked to symbiotic N fixation. Additionally, the isolates exhibited some other PGP properties. However, no specific PGP functions were linked to improved plant N acquisition but could potentially be linked to the FLs secretion. For future investigation, the mechanisms underlying improved plant N uptake should be assessed to gain a more in-depth understanding. Full article

Drosicha corpulenta (Hemiptera: Monophlebidae) is a major polyphagous pest affecting street and garden trees in arid regions of northern China, causing increasing damage in newly developed cities like Cocodala, Xinjiang. This study was conducted from 2024 to 2025 to investigate this pest’s life cycle, key damage periods, and spatial distribution in seven host plants, focusing on nymph emergence, female soil entry, and overwintering egg distribution. The results show that D. corpulenta has one generation per year, which overwinters as eggs. Nymphs emerge in early March, and male pupation occurs from mid-April to early May. Females mate after the third molt in early to mid-May and enter the soil to lay eggs from late May to early June, with consistent timing over two years. The suitability of the host varied significantly: Platanus × hispanica was the most preferred, with the highest daily nymph emergence of 840.8 individuals in 2024 and 1196.0 in 2025, followed by Prunus padus and five other plant species (Populus spp., Fraxinus chinensis, Styphnolobium japonicum, Pinus spp., and Malus spectabilis). Female soil entry reached a maximum on 23 May (979.8 individuals⁻¹ day⁻¹) and gradually decreased with increasing distance from the trunk. Overwintering eggs showed no obvious azimuthal bias, but were mainly concentrated near the trunk (0–30 cm) and in shallow soil (0–10 cm; 179.8 eggs per 100 g composite soil sample per sampling point), decreasing sharply in number with distance and depth. Both Taylor’s power law and Iwao’s regression confirmed the aggregated distribution. This study identifies key phenological stages, highly susceptible hosts, and the near-trunk shallow soil layer as critical for oviposition and overwintering and provides a basis for precise monitoring and targeted control in urban green spaces. Full article

Crabapples (Malus spp.) are important ornamental trees in northern temperate regions. However, their phenotypic diversity and ornamental values remain poorly characterized, due to a lack of systematic comparison between introduced and domestically bred cultivars/lines. This knowledge gap limits the effective utilization of their germplasm. In this study, 111 floral, foliar, fruit, and tree architectural traits were measured across 93 introduced (North American) and 118 domestically bred (Chinese) cultivars/lines. Comparative analyses using Shannon–Wiener (H′) and Pielou’s evenness (J) indices revealed that floral traits exhibited the highest phenotypic diversity, followed by fruits, leaves, and tree architecture. Among these, 51 key traits (e.g., budlet color, leaf area, and fruit shape) showed above-average diversity, while others (e.g., flower type, leaf cracking, and exocarp color) were less uniform, indicating rare phenotypes. Domestically bred cultivars showed significant improvements in flower color and type, mature leaf shape and size, and fruit characteristics, including novel budlet, bud and petal colors, increased stamen numbers, semi-double or double flowers, and diverse fruit colors. A multi-dimensional ornamental evaluation (Analytic Hierarchy Process) identified 26 superior genotypes and several organ-specific selections for flower- (26), fruit- (25), foliage- (21), and tree architecture-viewing (14) purposes. These findings provide a theoretical basis for updating Malus distinctness, uniformity, and stability (DUS) guidelines, targeted breeding, and strategic landscape applications, highlighting the potential of both introduced and domestic germplasm for ornamental improvement. Full article

Crabapples (Malus spp.) are widely planted ornamental and multipurpose trees in temperate regions and represent an important component of forest and landscape resources. However, the absence of a standardized classification framework has led to nomenclatural confusion, hindering germplasm conservation, breeding, and international exchange. In this study, 80 introduced crabapple cultivars preserved in the germplasm repository of Nanjing Forestry University were systematically evaluated using 55 morphological traits of flowers, leaves, fruits, and tree architecture. A hierarchical framework was established based on flower type and corolla color, dividing cultivars into Single, Semidouble, and Double Flower groups, with further subdivisions of Single cultivars by color. Numerical taxonomy (R- and Q-type clustering) validated the robustness of this framework, identifying petal number and corolla color as the most consistent traits across cultivars and seasons (inter-cultivar CV < 10%), serving as reliable diagnostic indicators, although within-cultivar variation was not quantified. The proposed system resolved frequent misidentifications (e.g., M. ‘Kelsey’ and M. ‘Molten Lava’) and provided standardized descriptors for cultivar identification. Beyond taxonomy, the framework enhances germplasm management, supports nursery production and landscape forestry, and facilitates international exchange of ornamental resources. These findings highlight the potential of integrating morphological and numerical approaches for germplasm diversity assessment and contribute to the development of a unified global classification system for ornamental crabapples. Full article

The objective of this study was to evaluate the impact of two nitrogen doses in combination with strong creeping fescue (Festuca rubra L. ssp. rubra Gaudin) and Chewing’s red fescue (Festuca rubra L. ssp. commutata Gaudin) used as living mulches on the weed community in an apple tree (Malus domestica Borkh.) orchard. The cover grasses were sown in the tree rows, and herbicide fallow served as the control. Grass living mulches effectively reduced the number and share of annual weed cover and limited the spread of perennial plants compared with herbicide fallow. Use of F. rubra L. subspecies did not favor the biodiversity of the orchard agroecosystem flora, due to the effective soil surface coverage by sod in the tree rows. Living mulch sod was characterized by lower variability in weed taxa compared with the abundant weed composition in the herbicide fallow, which also exhibited the highest number of weed taxa each year. Dominant species in the orchard across all treatments included Trifolium repens L. and Taraxacum spp. Doubling the nitrogen fertilization rate, while limiting the application area to the tree canopy, did not increase the perennial weed population in the living mulch sod. Both subspecies are useful as living mulch in a young apple orchard, but from the perspective of sod durability and weed control, strong creeping red fescue offers better prospects. Full article

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. Full article

Bee pollen (BP) is a very valuable bee product, and its value depends on its proteins, lipids, amino acids, carbohydrates, vitamins, minerals, and biologically active compounds such as phenolic compounds, which may change depending on the method of pollen preparation after collection and its storage conditions. Therefore, it is very important to determine when the decline in bioactive compounds in BP occurs during storage. The purpose of this study was to evaluate the changes in the content of ascorbic acid and phenolic compounds, and to determine the antioxidant activity of BP extracts depending on their preparation method and storage conditions over a 15-month period, with assessments conducted every 3 months. Dried pollen (at +28 °C on the first day and +35 °C on the second day) and frozen (−20 °C and −80 °C) BP samples were prepared. After 3 months of storage, there was no decrease of ascorbic acid in frozen BP; however, it decreased by 20% in dried BP (p < 0.05). It was determined that in frozen BP, the content of total phenolic compounds decreased by 12–14% (p < 0.05) after 6 months, and in dried BP, it decreased by 7% (p < 0.05) after 3 months. The levels of flavonoids decreased by 10–17% (p < 0.05) in BP after 6 months. Chlorogenic and p-coumaric acids have been observed as the most abundant phenolic acids in BP. During storage (the 6–15-month period), the strongest antiradical and reducing activity in vitro was estimated in the frozen (−80 °C) BP, which was 1.8–3.4-fold and 2.6–3.1-fold higher, respectively, compared to the dried BP extracts. In conclusion, significant results were obtained, showing better stability of phenolic compounds and ascorbic acid during storage in frozen BP compared to dried pollen. Melisopalynological analysis revealed a polyfloral pollen mixture, with Salix spp. and Brassica napus L. predominating in all samples, comprising 34.3% and 36.8%, respectively. Among these, Acer platanoides L., Malus domestica Borkh., and Taraxacum officinale L. were important minor pollens present in the samples examined. Full article

The Manchurian fruit moth, Grapholita inopinata (Heinrich) (Lepidoptera: Tortricidae), is an important pest of fruit crops, particularly apples (Malus spp., Rosaceae), and is classified as a quarantine pest in many European countries and other world regions. Until recently, this species was known only in Northeastern China, Japan, and Russia (from Eastern Siberia and the Far East). To determine the westernmost distribution of G. inopinata and assess its abundance, we conducted nine-year pheromone monitoring across 13 administrative regions of Russia from 2014 to 2018 and 2021 to 2024. A total of 1866 traps were deployed, capturing 31,962 G. inopinata specimens in 1811 traps. The species was newly detected in eight regions—seven in Asian Russia and one in European Russia (Perm Krai). These findings doubled the moth’s known range on the Asian continent and extended its western boundary to 56° E in European Russia. Between 2021 and 2024, G. inopinata was generally found at low densities across the surveyed regions (≤10 males per trap per week), with the exception of Perm Krai, Omsk, and Novosibirsk Oblasts, where moderate abundance (up to 38 males per trap per week) was recorded. In contrast, from 2014 to 2018, moderate to high population densities (up to 94 males per trap per week), including mass occurrences (over 100 males per trap per week), were observed in Krasnoyarsk Krai, with an absolute peak capture of 303 males in one trap in June 2017. Notably, in 2015–2017, male flight activity in southern Krasnoyarsk Krai exhibited two distinct peaks: one in mid-to-late June and another from late July to mid-August, indicating the development of two generations. This is the first-ever record of a bivoltine seasonal cycle for G. inopinata in Siberia. These findings are critical for improving pest risk assessments and developing early detection strategies, supporting more effective monitoring and management approaches of this orchard pest. Full article

Extending the shelf life of perishable food, such as apples, and storing them in cold conditions and/or controlled atmospheres have been of great interest in the last decades. Apples are very valuable fruits with many health benefits, but during storage at ambient conditions, they ripen quickly and lose moisture, causing lower crispness or other negative effects, resulting in waste problems. There has been growing attention to protective edible coatings or active packaging films based on biopolymers and natural bioactive substances. Edible coatings and films allow for combination with functional ingredients or compounds, affecting the maintenance of the postharvest quality of fruits and vegetables. They also ensure the preservation of the sensory characteristics of food, and they can have antimicrobial or antioxidant properties. All these aspects play a significant role in the storage of apples, which can also help prevent waste, which is in line with the circular economy approach. The functionality of coatings and films is closely related to the type, content, and composition of active compounds, as well as their interaction with biopolymers. Active coatings with the addition of different functional compounds, such as plant extracts, phenolic acids, and nanoparticles, can be an alternative solution affecting the postharvest quality of apples during storage, maintaining the fruit’s stability, and thus minimising their waste. The most important issues related to the latest reports on improving the postharvest quality of apples using edible coatings incorporated with various active substances were evaluated. Agricultural conditions and factors that affect the postharvest quality of apples were described. The requirements for protective coatings for apples should be focused on low-cost materials, including waste-based resources, good miscibility, and compatibility of components. Those factors combined with the storage conditions may result in shelf life extension or retention of the postharvest quality of apples, regardless of the variety or cultivation techniques. Full article

For this article, we evaluated whether wounds would affect the pathogenicity and virulence of Colletotrichum sp. isolates on Musa spp. banana cultivars. We further assessed the potential of cross-colonization with other fruit species and investigated the molecular and phylogenetic characterization of the most virulent isolates. Firstly, we collected dwarf bananas showing anthracnose symptoms from commercial markets in the city of Gurupi, Tocantins State, Brazil, and isolated Colletotrichum sp. under controlled conditions prior to identification. The virulence was assessed on wounded and unwounded banana fruits, identifying the most virulent isolate by exposure tests on fruits of the “prata”, “maçã”, “marmelo”, and “terra” banana cultivars. We also subjected specimens of mango (Mangifera indica), papaya (Carica papaya), and apple (Malus domestica) fruits to the exposure tests. Our results indicated that pathogenicity varies with the isolate (with C2, C8, and C10 as the most virulent), fruit condition (wounded fruits are the most susceptible), and cultivars (terra, marmela, and maça are the most susceptible). All isolates were more virulent on wounded bananas, while those on unwounded ones showed lower virulence. Among the banana cultivars, “prata” fruits were the most susceptible, regardless of wounding. Additionally, Colletotrichum isolates from dwarf bananas were pathogenic to mango, papaya, and apple fruits. Furthermore, our results demonstrated that the most virulent isolates belong to the species C. musae. Collectively, our findings reinforce the relevance of minimizing post-harvest wounds on banana fruits and highlight the risks of cross-infection when storing bananas alongside other fruit species. Full article

Species of the genus Colletotrichum are among the most important plant pathogens globally, as they are capable of infecting many hosts—apple (Malus spp.) and other fruit and woody plant species—but also vegetable crops, cereals, legumes, and other annual and perennial herbaceous plants. The apple (Malus spp.) is attacked by various species from the genus Colletotrichum, whereby 27 different species from this genus have been described as the causative agents of apple bitter rot (ABR) and 15 as the cause of Glomerella leaf spot (GLS). These species generally belong to one of three species complexes: Colletotrichum acutatum, Colletotrichum gloeosporioides, and Colletotrichum boninense. The largest number of apple pathogens of the genus Colletotrichum belong to the species complex C. acutatum and C. gloeosporioides. However, further data on these species and the interactions between the species complexes of the genus Colletotrichum that cause these two apple diseases is needed for the development of effective control measures, thus ensuring successful and profitable apple cultivation. To contribute to this endeavor, a comprehensive review of the causative agents of ABR and GLS from the genus Colletotrichum is provided. In addition to presenting the species’ current names, distribution, economic significance, and the symptoms they cause in apple, their development cycle, epidemiology, and molecular detection strategies are described, with a particular emphasis on control measures. Full article

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. Full article

Infestations of pests are perhaps an anthropogenic catastrophe for trees. Aeolesthes sarta (Sart longhorned beetle—SLB) is one of the most severe pests that cause serious damage to a number of hardwood tree species, i.e., Populus, Salix, Acer, Juglans, and Malus. To investigate people’s attitudes towards pest damage cost and future control extent of SLB, a door-to-door method was adopted to survey two major cities (Quetta—QU and Peshawar—PE) of the northwestern region of Pakistan where this pest has caused severe damage. Respondents were asked about SLB pest knowledge, pest damage costs, preferences for control choices, and program extent. According to respondents, more trees (181 ± 1.20 trees/ha/annum) were damaged in QU compared to PE. Populus spp. was the dominant tree genre that attacked and damaged the most. Around 85% of respondents from both cities stated the pest damage cost was calculated as high for QU (480,840.80 ± 4716.94$/annum) compared to PE. Respondents in both locations strongly supported (more than 82%) biological control of future SLB outbreaks. They all agreed that protecting ecologically vulnerable places and wildlife habitats should be the primary priority in a future SLB outbreak. Respondents from both cities who preferred to protect more land area in future SLB outbreaks were calculated to be high for QU (61%) compared to PE (58%). However, city variations in opinions regarding forest-type priority that should be protected and control options were observed. Socio-demographic characteristics were discovered to impact pest damage cost positively, as well as preferred SLB control extent. The findings of this study can help policymakers and forest managers develop publicly permissible pest control plans and make more accurate predictions about future pest outbreaks. Full article

The plant pathogenic fungus Cytospora is notoriously known for causing woody plant canker diseases, resulting in substantial economic losses to biological forests and fruit trees worldwide. Despite their strong negative ecological impact, the existing and prospective distribution patterns of these plant pathogens in China, according to climate change, have received little attention. In this study, we chose three widely dispersed and seriously damaging species, namely, Cytospora chrysosperma, Cytospora mali, and Cytospora nivea, which are the most common species that damage the Juglans regia, Malus domestica, Eucalyptus, Pyrus sinkiangensis, Populus spp., and Salix spp. in China. We utilized ecological niche modeling to forecast their regional distribution in China under four climate change scenarios (present, SSP 126, SSP 370, and SSP 585). The results show that temperature-related climate factors limit the current distribution ranges of the three species. Currently, the three studied species are highly suitable for northeast, northwest, north, and southwest China. Under future climate scenarios, the distribution ranges of the three species are projected to increase, and the centers of the adequate distribution areas of the three species are expected to shift to high-latitude regions. The three species coexist in China, primarily in the northwest and north regions. The ecological niches of C. chrysosperma and C. nivea are more similar. The distribution range of C. mali can reach the warmer and wetter eastern region, whereas C. chrysosperma and C. nivea are primarily found in drought-prone areas with little rainfall. Our findings can help farmers and planners develop methods to avoid the spread of Cytospora spp. and calculate the costs of applying pesticides to reduce contamination and boost yields. Full article

Sixty-seven apple tree accessions from the Centre for the Conservation of Agricultural Biodiversity of Tenerife (CCBAT) were molecularly characterised for the first time with 13 simple sequence repeats (SSRs). Additionally, previously studied genotypes from the Canary Islands (Tenerife, La Palma and Gran Canaria), Galicia, Asturias and commercial reference varieties were studied to identify possible synonymies and genetic structures, in order to improve the conservation of this genus in the germplasm bank. Thirty-three different genotypes were found in the new accessions analysed (51% clonality): sixteen of them (48%) exclusive to Tenerife, with no genetic coincidence with previous studies, making a total of thirty-three genotypes unique to Tenerife and sixty-five in the whole of the Canary Islands. The analysis of the population structure grouped the apple genotypes into two reconstructed panmictic populations (RPPs), one formed by local varieties or traditional ones (‘Peros’), RPP1, from all the regions studied, and the other formed by local and commercial varieties, RPP2. The RPP1 genotypes identified in Tenerife seem to show better adaptation to low chill, with a positive and significant correlation (0.388, p < 0.01), highlighting the importance of local varieties and the need for their conservation. This is the first study reporting significant correlation between genetic structure and chilling requirements. Full article