Search Results (27)

Background/Objectives: Amelogenesis imperfecta (AI) represents a heterogeneous group of inherited disorders affecting the quality and quantity of dental enamel, making clinical diagnosis challenging. This study aimed to identify genetic variants in Slovenian patients with non-syndromic AI and to evaluate enamel morphology using radiographic parameters. Methods: Whole exome sequencing (WES) was performed on 24 AI patients and their families. Panoramic radiographs (OPTs) were analyzed using Fiji ImageJ to assess crown dimensions, enamel angle (EA), dentine angle (DA), and enamel–dentine mineralization ratio (EDMR) in lower second molar buds, compared to matched controls (n = 24). Two observers independently assessed measurements, and non-parametric tests compared EA, DA, and EDMR in patients with and without disease-causing variants (DCVs). Statistical models, including bootstrap-validated random forest and logistic regression, assessed variable influences. Results: DCVs were identified in ENAM (40% of families), AMELX (15%), and MMP20 (10%), including four novel variants. AI patients showed significant enamel deviations with high reproducibility, particularly in hypomineralized and hypoplastic regions. DA and EDMR showed significant correlations with DCVs (p < 0.01). A bootstrap-validated random forest model yielded a 90% (84.0–98.0%) AUC-estimated predictive power. Conclusions: These findings highlight a novel and reproducible radiographic approach for detecting developmental enamel defects in AI and support its diagnostic potential. Full article

Alfalfa (Medicago sativa L.) is a globally significant forage crop with notable economic value. Gibberellins (GA₃) promote dormancy breaking and early germination whereas auxins (IAA) predominantly influence bud regeneration. This study investigated the effects of exogenous gibberellins and indole acetic acid on the regeneration and biomass of crown buds in two alfalfa varieties with different dormancy levels. The experiment involved five concentrations each of gibberellins (0 mg/L, 10 mg/L, 20 mg/L, 30 mg/L, and 40 mg/L) and auxins (0 mg/L, 5 mg/L, 10 mg/L, 15 mg/L, and 20 mg/L). The results indicated that both exogenous gibberellins and auxins significantly increased the endogenous levels of these hormones in the crown buds, while decreasing abscisic acid (ABA) levels. There was also a significant increase in sugar and total nitrogen content in the buds. Treatments with exogenous gibberellins enhanced the number of crown buds and the aboveground biomass per plant, with the best results at 30 mg/L. Auxin treatments showed the largest increase in aboveground biomass per plant at 15 mg/L. In summary, 30 mg/L gibberellins or 15 mg/L auxins is recommended as the optimal spraying concentration. This research provides practical evidence for the regulation of exogenous growth regulators in alfalfa cultivation. Full article

Ash dieback (ADB), driven by the invasive fungus Hymenoscyphus fraxineus, poses a significant environmental and financial risk throughout Europe. Fraxinus excelsior (European ash), an essential part of forest ecosystems, has seen death rates as high as 85% in impacted areas, threatening its ecological roles and economic importance. This study examines the relationship between the phenological traits of ash clones, particularly the timing of spring bud burst, and their susceptibility to H. fraxineus infection. The study was conducted in a clonal seed orchard located in Northeastern Poland, encompassing 31 ash clones from different bioclimatic regions. Phenological analyses of bud burst were carried out from early April to late May during the years 2018–2020, and crown damage and defoliation levels were assessed multiple times throughout the growing season. The results confirm that clones with earlier bud burst exhibit significantly higher survival rates and reduced crown damage. Observations revealed that clones with earlier bud burst showed a 30% higher survival rate and up to 40% less crown damage compared to clones with later phenology. The timing of bud burst was strongly correlated with susceptibility to ash dieback (R² = 0.37, p < 0.001). Statistical analyses, including ANOVA and mixed models, revealed significant differences in susceptibility to infection among clones from different bioclimatic regions. These findings underscore the importance of biological timing as a key factor in selecting genotypes resilient to ash dieback. The study highlights the potential of breeding approaches that focus on early bud burst traits to enhance the survival and vitality of ash populations. The results provide essential insights for developing adaptive forest management practices aimed at conserving ash resources and maintaining biodiversity in the face of climate change and the ongoing spread of the pathogen. Full article

Culinary rhubarb is grown for its large, thick leaf petioles. Red-stalked cultivars and selection are more attractive for the fresh market and processing industry. In vitro cultures are important for rapidly multiplying value genotypes and producing plants free of viruses. This study aimed to develop an in vitro propagation method for six rhubarb selections from the Raspberry (R1, R2, R3), Leader (L1, L2), and Karpow Lipskiego (KL) groups. In addition, the planting material of six rhubarb selections was subjected to phytochemical analysis using the HPLC method to assess the content of bioactive compounds. The cultures were initiated from underground buds on the crowns. The initial growth was obtained for 45 to 75% of initial explants because of bacterial contamination and low bud activity of some genotypes. The type and concentration of cytokinin and its interaction with gibberellin acid (GA₃) were shown to have a significant effect on the cyclic multiplication and commercially interesting rate of all rhubarb genotypes. A high in vitro rooting frequency, 93.7 to 95.8% for rhubarb Raspberry, 94.3 to 100% for rhubarb Leader, and 96.7% KP selections were obtained after two-cycle rooting on a medium containing IBA and NAA. The polyphenolic compounds, such as cyanidin-3-O-rutinoside, rhaponticin, resveratrol, caffeic acid, p-coumaric acid, cinnamic acid, syringic acid, and ferulic acid were detected in selected rhubarb genotypes. The highest content of anthocyanins (2.9 mg·1 g⁻¹ DM) and rhaponticin (107.8 µg·1 g⁻¹ DM) was found in Raspberry selections. On the other hand, Leader selections were characterized by the highest content of resveratrol (0.25 µg·1 g⁻¹ DM) and phenolic acids (1.3 µg·1 g⁻¹ DM). The less attractive for functional food production seems to be KL selection. Full article

Amid increasing deforestation, surface fires reaching the forest understory are one of the primary threats to Amazonian ecosystems. Despite extensive research on post-fire mortality in woody species, the literature on palm resilience to fire is scant. This study investigates post-fire mortality in four understory palms, namely Bactris maraja Mart., Chamaedorea pauciflora Mart., Geonoma deversa (Poit.) Kunth, Hyospathe elegans Mart., and juvenile individuals of Euterpe precatoria Mart. (açaí palm). The objectives included (a) comparing post-fire responses; (b) developing mortality models based on severity variables; and (c) evaluating if diameter protects bud stems from heat flux. Conducted at the edge of an Ombrophylous Forest in Alto Juruá Acre, Brazil (7°45′ S, 72°22′ W), the experiment subjected 85 individuals to controlled burning in a 1 m² area near the palm stem, with temperature sampling using K thermocouples. The results showed varying mortality rates among species, with a larger palm stem diameter correlating to reduced mortality. Crown burning patterns significantly influenced mortality, especially for Euterpe precatoria. The species exhibited diverse regrowth capacities, with B. maraja showing the highest number and tallest basal resprouts. The variation in morphology among species appeared to be more important than the amount of heat flux applied to each individual involved in the experiment, as no significant difference was observed in the time–temperature history measured. This study underscores post-fire plant mortality as a critical indicator of fire severity, essential for understanding its ecological impacts. Full article

Trees that grow in close proximity to other trees are subject to crown and branch abrasion, causing mechanical injury. The loss of branch tips and buds through abrasion can affect the architecture and growth of tree crowns. This research quantifies the impacts of crown abrasion between neighboring trees of several deciduous species and how crown abrasion may influence stand dynamics. Tree interactions were evaluated during the dormant and growing seasons to determine how wind-generated movement affects crowns under foliated and un-foliated conditions. Branch elongation was measured in tree crowns where growth was both inhibited and uninhibited by adjacent trees. Bud durability was evaluated by growing season for species with determinate and indeterminate shoot growth forms using a pendulum impact tester. Crown movement during wind events was assessed by using three-axial accelerometers in the outermost points of tree crowns. Accelerometers logged the movement of branches in the tree crown. By using both the crown sway acceleration and associated bud durability and mass data, the possible force necessary to break or abrade buds and branches was calculated at different wind speeds. Branch elongation was greater for most species on the exposed side of the crown that was not affected by adjacent trees. Preformed buds from the determinate growth form were determined to have greater durability than sustained growth or indeterminant buds. Acceleration from wind gusts increased more rapidly as wind speed intensified in the growing season when leaves were on the tree than in the dormant season. This research suggests that crown abrasion contributes to the development of mixed species stands by reducing crown size and growth therefore allowing slower-growing species with determinant growth to stratify above faster growing trees with indeterminant growth. Full article

The rapid advancement of genetic technologies has made it possible to modify various plants through both genetic transformation and gene editing techniques. Poplar, with its rapid in vitro growth and regeneration enabling high rates of micropropagation, has emerged as a model system for the genetic transformation of woody plants. In this study, Populus × berolinensis K. Koch. (Berlin poplar) was chosen as the model organism due to its narrow leaves and spindle-shaped crown, which make it highly suitable for in vitro manipulations. Various protocols for the Agrobacterium-mediated transformation of poplar species have been developed to date. However, the genetic transformation procedures are often constrained by the complexity of the nutrient media used for plant regeneration and growth, which could potentially be simplified. Our study presents a cheaper, simplified, and relatively fast protocol for the Agrobacterium-mediated transformation of Berlin poplar. The protocol involved using internode sections without axillary buds as explants, which were co-cultivated in 10 µL droplets of bacterial suspension directly on the surface of a solid agar-based medium without rinsing and sterile paper drying after inoculation. We used only one regeneration Murashige and Skoogbased medium supplemented with BA (0.2 mg·L⁻¹), TDZ (0.02 mg·L⁻¹), and NAA (0.01 mg·L⁻¹). Acetosyringone was not used as an induction agent for vir genes during the genetic transformation. Applying our protocol and using the binary plasmid pBI121 carrying the nptII selective and uidA reporter genes, we obtained the six transgenic lines of poplar. Transgenesis was confirmed through a PCR-based screening of kanamycin-selected regenerants for the presence of both mentioned genes, Sanger sequencing, and tests for detecting the maintained activity of both genes. The transformation efficiency, considering the 100 explants taken originally, was 6%. Full article

Pineapple fruit, which is cultivated in tropical and subtropical areas, is processed by the food industry, generating a large amount of waste. Using pineapple by-products in animal nutrition could reduce feeding costs and contribute to the containment of pollution. The chemical composition and the in vitro fermentation of five pineapple by-products (crown, bud end, peel, core, and pomace) from two West African pineapple varieties (Smooth Cayenne—SC and Sugarloaf—SL) were evaluated. Significant differences were observed between the varieties and by-products. The dry matter (DM) content was low and superimposable between varieties, averaging 17.7%. On a DM basis, pomace showed the highest protein content (SC 8.10% and SL 8.81%, p < 0.001), whereas the crown showed the highest (p < 0.001) NDF content (47.62% and 39.01% for SC and SL, respectively). Due the high sugar content, the core and pomace showed high in vitro organic matter degradability (SC: 85.09% and SL: 83.98%), estimated metabolizable energy (SC: 7.91 KJ/kg and SL: 7.66 KJ/kg), and volatile fatty acid production (96.86 mmol/g and 90.62 mmol/g). Based on chemical composition and in vitro digestibility results, this study suggests that pineapple by-products have the potential to be used in ruminants’ diets, considering the crown, bud end, and peel as fiber sources and the core and pomace as substitutes or supplements to concentrate feedstuffs. Further research should be conducted on the storability of these by-products through in vivo trials evaluating animals’ performances and the quality of their products. Full article

Day-neutral multiflora chrysanthemums can flower throughout the year without being influenced by daylength and have great application value in gardens. Studying heterosis and the genetic basis of important traits in day-neutral chrysanthemums can accelerate the breeding of new cultivars. In this research, a genetic population was constructed by crossing 135 F₁ hybrid progeny from the day-neutral chrysanthemum ‘82-81-19’ (female parent) and the late-flowering chrysanthemum ‘388Q-76’ (male parent). Six traits, including abnormal (crown) bud, plant height, plant crown width, budding date, full flowering date, and number of petal layers, were selected for inheritance and heterosis analyses, and a single-generation major gene plus polygene mixed inheritance model was used to perform mixed inheritance analysis on these traits. The results indicated that the six traits were widely segregated in the F₁ population, with the coefficient of variation (CV) ranging from 30% to 84%. The phenomena of heterosis and extra-parent segregation existed generally in F₁ progeny, and the ratio of heterosis value of mid-parents (RHm) for the six traits was 45.5%, 2%, 2%, 6%, 6%, and −0.3%, respectively. The mixed genetic analysis showed that the abnormal (crown) bud and budding date were fitted to the B-3 model and controlled by two pairs of additive major genes. The plant height and plant crown width were fitted to the A-0 model, and no major gene was detected. The full flowering date was fitted to the A-1 model and was controlled by one pair of major genes. The number of petal layers was fitted to the B-1 model and controlled by two pairs of additive–dominant major genes. The heritabilities of major genes for abnormal bud, budding date, full flowering date, and the number of petal layers were 1.0, 0.9871, 0.7240, and 0.5612, respectively, indicating that these traits were less affected by environmental factors. Using a percentile scoring method, eight day-neutral chrysanthemum genotypes were selected from the hybrid progeny. Full article

Autophagy is a conserved cellular process that functions in the maintenance of physiological and metabolic balance. It has previously been demonstrated to improve plant tolerance to abiotic stress. Numerous autophagy–related genes (ATGs) that regulate abiotic stress have been identified, but there have been few functional studies showing how ATGs confer cold stress tolerance. The cold transcriptome data of the crown buds that experienced overwintering of the alfalfa (Medicago sativa L.) showed that MsATG13 is upregulated in response to cold stress. In the present study, we found that MsATG13 transgenic tobacco enhanced cold tolerance compared to wild–type (WT) plants. Transmission electron microscopy demonstrated that transgenic tobacco overexpressing MsATG13 formed more autophagosomes than WT plants in response to cold stress conditions. The transgenic tobacco increased autophagy levels due to upregulation of other ATGs that were necessary for autophagosome production under cold stress conditions. MsATG13 transgenic tobacco also increased the proline contents and antioxidant enzyme activities, enhancing the antioxidant defense capabilities under cold stress conditions. Furthermore, MsATG13 overexpression decreased levels of superoxide anion radicals and hydrogen peroxide under cold stress conditions. These findings demonstrate the role of MsATG13 in enhancing plant cold tolerance through modulation of autophagy and antioxidant levels. Full article

With the progress of computer vision and the development of unmanned aerial vehicles (UAVs), UAVs have been widely used in forest resource investigation and tree feature extraction. In the field of crown width measurement, the use of traditional manual measurement methods is time-consuming and costly and affects factors such as terrain and weather. Although the crown width extraction method based on the segmentation of UAV images that have recently risen in popularity extracts a large amount of information, it consumes long amounts of time for dataset establishment and segmentation. This paper proposes an improved YOLOv7 model designed to precisely extract the crown width of Metasequoia glyptostroboides. This species is distinguished by its well-developed terminal buds and distinct central trunk morphology. Taking the M. glyptostroboides forest in the Qingshan Lake National Forest Park in Lin’an District, Hangzhou City, Zhejiang Province, China, as the target sample plot, YOLOv7 was improved using the simple, parameter-free attention model (SimAM) attention and SIoU modules. The SimAM attention module was experimentally proved capable of reducing the attention to other irrelevant information in the training process and improving the model’s accuracy. The SIoU module can improve the tightness between the detection frame and the edge of the target crown during the detection process and effectively enhance the accuracy of crown width measurement. The experimental results reveal that the improved model achieves 94.34% mAP@0.5 in the task of crown detection, which is 5% higher than that achieved by the original model. In crown width measurement, the R² of the improved model reaches 0.837, which is 0.151 higher than that of the original model, thus verifying the effectiveness of the improved algorithm. Full article

Against the background of climate change, we studied the effects of a severe summer drought on buds of European beech (Fagus sylvatica L.) saplings and on leaves formed during the subsequent spring in trees attributed to different drought-damage classes. For the first time, we combined assessments of the vitality (assessed through histochemical staining), mass and stable carbon isotope ratios (δ¹³C) of buds from drought-stressed woody plants with morphological and physiological variables of leaves that have emerged from the same plants and crown parts. The number, individual mass and vitality of the buds decreased and δ¹³C increased with increasing drought-induced damage. Bud mass, vitality and δ¹³C were significantly intercorrelated. The δ¹³C of the buds was imprinted on the leaves formed in the subsequent spring, but individual leaf mass, leaf size and specific leaf area were not significantly different among damage classes. Vitality and δ¹³C of the buds are suitable indicators of the extent of preceding drought impact. Bud vitality may be used as a simple means of screening saplings for the flushing capability in the subsequent spring. European beech saplings are susceptible, but—due to interindividual differences—are resilient, to a certain extent, to a singular severe drought stress. Full article

Rhizome cutting is prevalent in propagation for Hemerocallis citrina Baroni. This study aimed to reveal the influence of rhizome weight on plantlet growth, and evaluate a new cutting protocol. Three levels of rhizome weight (big (BR), medium (MR) and small (SR)) were compared by measuring plantlet growth four times during cutting propagation. Sectioning rhizomes longitudinally along shaft axis of crown into 2, 3 or 4 parts (S2, S3 and S4), was tested on rhizomes with two bud sizes (Large bud (LB), Small bud (SB)). Propagation coefficient, the number of plantlets obtained per rhizome, kept similar regardless of rhizome weight, while S3 and S4 increased propagation coefficient. Rhizome weight changed the relative growth rates on different dates. SR resulted in lower aboveground dry biomass, leaf area, total fibrous root length, relative total fibrous root length growth rate and N deficiency compared to BR. Sucrose concentration in rhizome decreased with time and fructose concentration was lowest in MR at the end of experiment. Aboveground dry biomass and total fibrous root length were lowest in S4, followed by S3 and S2. Rhizome weight and number of sectioning per rhizome influence cutting propagation, and sectioning rhizomes into three pieces has higher propagation coefficient and less retardation on growth. According to N deficiency in plantlets during the propagation, N fertiliser is probably needed during cutting. Full article

Asexual propagation techniques for producing good quality germplasm for breeding and dissemination purposes have proven difficult for acacia species comprised of mature planting material. The study was conducted to study the effect of rejuvenation on the rooting ability of mature cuttings. Shoots were induced from the lower branch by cutting a part of the mature branch of the crown and leaving it horizontally on the propagation bench under the misting system. Shoots were harvested and further used as stem cuttings to evaluate their rooting ability through the application of rooting hormone. The rooting ability of the cuttings is highly variable among species. The percentage of stem sections producing juvenile shoots was similar for Acacia mangium Willd. (88%) and Acacia auriculiformis A.Cunn. ex Benth. (90%). Only 52% of stem sections were able to produce shoots for Acacia crassicarpa A.Cunn. ex Benth., followed by Acacia aulococarpa A.Cunn. ex Benth. with only 31%. Overall, A. auriculiformis rooted better and recorded the highest mean value for all traits tested. Hormone treatment significantly enhances the rooting ability of A. auriculiformis and A. mangium. However, A. aulococarpa and A. crassicarpa did not respond well to the treatment. Rejuvenated stem cuttings were rooted better than mature cuttings, producing the highest mean value for all traits tested in all species, with or without hormone treatment. Results indicated that it is possible to rejuvenate mature cuttings through bud break in a controlled environment. Full article

Lycium ruthenicum Murr. is one of the most important shrubs grown in northwest China. Healthy buds and leaves of L. ruthenicum Murr. were selected for the present study. Flower development was divided into six stages, namely, flower bud pre-differentiation (I), late flower differentiation (II), squaring stage (III), dew crown period (IV), open stage (V) and senescent stage (VI). Endogenous hormone content and specific value, soluble sugar, sucrose, starch, and soluble protein were measured, and ABA/IAA, ABA/GA₃, ZR/IAA, ZR/GA₃, and C/N were calculated in buds and leaves at stage VI. The results showed that ABA, GA₃, and ZR content of buds significantly increased from flower bud pre-differentiation to late flower differentiation stage. However, ABA, GA₃, and ZR content of leaves had the opposite change trend. From open stage to senescent stage, IAA, ABA, and GA₃ content of buds and leaves significantly increased in L. ruthenicum Murr. However, ZR content of buds and leaves significantly decreased from open stage to senescent stage. ABA/IAA, ABA/GA₃, ZR/IAA, and ZR/GA₃ values of buds significantly increased from lower bud pre-differentiation to late flower differentiation stage. However, ABA/IAA, ABA/GA₃, ZR/IAA, and ZR/GA₃ values of leaves significantly decreased from lower bud pre-differentiation to late flower differentiation stage. ABA/IAA and ABA/GA₃ of buds significantly increased from open stage to senescent stage, but ZR/IAA and ZR/GA₃ of buds significantly decreased from open to senescent. At this stage, ABA/IAA, ABA/GA₃, ZR/IAA, and ZR/GA₃ significantly decreased in L. ruthenicum Murr. The higher soluble sugar and sucrose content in the buds and leaves were beneficial to the flower bud differentiation of L. ruthenicum. The increasing of soluble sugar improved the energy basis to florescence and senescent. The carbohydrates metabolism enhanced from open stage to senescent stage and nitrogen metabolism reduced from open stage to senescent stage of L. ruthenicum. Full article