Search Results (836)

Climate change is intensifying drought frequency and severity, posing increasing challenges for tropical forest species whose growth and survival depend on water availability. Ochroma pyramidale (Cav. ex Lam.) Urb. (balsa) is a fast-growing pioneer tree that plays important ecological roles, and it is valued for its lightweight timber, yet little is known about its drought tolerance or intraspecific variation among populations. This study evaluated the morphophysiological responses of O. pyramidale seedlings from three provenances spanning a rainfall gradient (850–6275 mm year⁻¹) under controlled soil moisture levels. The experiment followed a completely randomized factorial design with two factors, provenance (high-, medium-, and low-rainfall origins) and soil moisture (100%, 50%, and 20% field capacity), with six replications per treatment (n = 54 total plants). Drought significantly affected growth, water status, and physiological variables. Seedlings maintained high relative water content and photosynthetic pigment concentration under moderate stress (50% field capacity) but showed marked declines at 20% field capacity. Soluble sugar accumulation increased with drought intensity, suggesting osmotic adjustment, while root proliferation was enhanced under moderate stress (50% FC), evidenced by significantly higher Total Root Length (TRL) and Number of Branch Points (NBP). Provenance effects were weak, with only the number of leaves differing significantly among provenances. These results demonstrate that O. pyramidale tolerates moderate drought through physiological adjustment and root plasticity, supporting its use in reforestation and restoration initiatives in water-limited tropical environments. Full article

Pumpkin seedlings serve as rootstocks for watermelon grafting, and the partial leaf trimming operation performed approximately two days before grafting is crucial for the survival rate of grafted watermelon seedlings. Extracting the position of the main veins of the leaf is a prerequisite for achieving automated partial pruning. The existing methods have problems such as low segmentation accuracy and misclassification between primary and branch veins in the pumpkin seedling segmentation task. This study proposes a three-classification segmentation model Dynamic Region Enhancement Transformer (DRE-Former) of main vein, branch vein and background, as well as a post-processing system. The encoder of DRE-Former consists of two modules. The former is Dynamic Frequency Conv and Normalized Efficient Conv (DN Block), which can enhance the feature extraction ability for small targets. The latter is the Region Transformer Block, which enhances the ability to distinguish between the main vein and the branch vein. In addition, in the skip connection part of the model, a Skip Connection Fusion Block (SCF Block) has been added, which can reduce the dilution degree of detailed features. The post-processing section outputs the cutting position and cutting Angle through rule-based methods and geometric analysis. The experimental results show that the proposed model achieves mean Intersection-over-Union (mIoU) and Overall Accuracy (OA) of 90.80% and 95.88%, respectively, outperforming the comparative models. In stability and error testing, the average standard deviation is 0.60, and the average relative error is 11.90%. Compared with the primary mIoU data in the dataset, the average relative error differs by only 2.11%. The post-processing system enables the accurate determination of cutting positions and angles, but it has a strong dependence on the segmentation model. The research can provide reliable technical support for the subsequent automatic cutting equipment for pumpkin seedlings. Full article

In the field management of maize, phenomena such as missed sowing and empty seedlings directly affect the final yield. By implementing seedling replenishment activities and promptly evaluating seedling growth, maize output can be increased by improving seedling survival rates. To address the challenges posed by complex field environments (including varying light conditions, weeds, and foreign objects), as well as the performance limitations of model deployment on resource-constrained devices, this study proposes a Lightweight Real-Time You Only Look Once (LRT-YOLO) model. This model builds upon the You Only Look Once version 11n (YOLOv11n) framework by designing a lightweight, optimized feature architecture (OF) that enables the model to focus on the characteristics of small to medium-sized maize seedlings. The feature fusion network incorporates two key modules: the Feature Complementary Mapping Module (FCM) and the Multi-Kernel Perception Module (MKP). The FCM captures global features of maize seedlings through multi-scale interactive learning, while the MKP enhances the network’s ability to learn multi-scale features by combining different convolution kernels with pointwise convolution. In the detection head component, the introduction of an NMS-free design philosophy has significantly enhanced the model’s detection performance while simultaneously reducing its inference time. The experiments show that the $mA{P}_{50}$ and $mA{P}_{50:95}$ of the LRT-YOLO model reached 95.9% and 63.6%, respectively. The model has only 0.86M parameters and a size of just 2.35 M, representing reductions of 66.67% and 54.89% in the number of parameters and model size compared to YOLOv11n. To enable mobile deployment in field environments, this study integrates the LRT-YOLO model with the ByteTrack multi-object tracking algorithm and deploys it on the NVIDIA Jetson AGX Orin platform, utilizing OpenCV tools to achieve real-time visualization of maize seedling tracking and counting. Experiments demonstrate that the frame rate (FPS) achieved with TensorRT acceleration reached 23.49, while the inference time decreased by 38.93%. Regarding counting performance, when tested using static image data, the coefficient of determination ($R^2$) and root mean square error (RMSE) were 0.988 and 5.874, respectively. The cross-line counting method was applied to test the video data, resulting in an $R^2$ of 0.971 and an RMSE of 16.912, respectively. Experimental results show that the proposed method demonstrates efficient performance on edge devices, providing robust technical support for the rapid, non-destructive counting of maize seedlings in field environments. Full article

Clubroot disease caused by Plasmodiophora brassicae has greatly affected the quality and yield of Chinese cabbage. Excavating the key resistance genes and verifying their function is important for clarifying disease resistance mechanisms. Virus-induced gene silencing (VIGS) technology has been widely used in gene function research. However, the VIGS system specifically designed for the functional analysis of clubroot resistance genes is currently unavailable. In this study, it was found that the vacuum infiltration VIGS method is more effective for gene silencing than the seed soaking method. When seedlings were VIGS-treated using vacuum infiltration for 10 min, genes were effectively silenced on the 6th-35th days (d) after treatment, ensuring high seedling survival rate and plant transformation rate. To investigate the optimal inoculation time with P. brassicae, plants were inoculated 3, 6, 9, and 15 d after VIGS treatment. Results showed that the difference of clubroot resistance between gene-silenced and control plants was most significant when plants were inoculated 6 d after VIGS treatment. This result suggests that, when the target gene began to silence (6 d after VIGS), immediate inoculation with P. brassicae should be suitable for the functional study of clubroot-resistance genes. Full article

The survival of Quercus species in the Mediterranean region is challenged by root diseases caused by Phytophthora cinnamomi Rands and Pythium spiculum Paul, as well as by drought. This study aimed to examine the interaction between both pathogens under varying soil moisture levels. Seedlings were inoculated with P. cinnamomi, Py. spiculum, or both, and exposed to soil moisture conditions ranging from saturation to drought. Results showed that P. cinnamomi caused high levels of root necrosis in saturated-to-moderately dry soils, but it was unable to cause infection under drought conditions. Conversely, Py. spiculum infected roots under drought but not under saturation conditions and was less virulent in wet soils compared to P. cinnamomi. In seedlings inoculated with both pathogens, symptoms were similar to those induced by P. cinnamomi alone, without any synergistic effect. This study highlights that P. cinnamomi and Py. spiculum infect oak roots across a range of soil moistures, with P. cinnamomi being the predominant pathogen in wet-to-moderately dry soils, and Py. spiculum being the predominant pathogen in droughted soils. Under current and projected future water deficit conditions, oak woodlands infected by both pathogens face a significant threat to their survival. Full article

Polyploidization is a powerful tool in plant breeding that can induce desirable morphological and physiological modifications. This study aimed to establish an efficient in vitro protocol for inducing autotetraploid plants in cherimoya (Annona cherimola Mill. cv. Fino de Jete) using colchicine. Hypocotyl explants from seedlings germinated in vitro were treated with different colchicine concentrations (0.01–0.2%) for 24 and 48 h, and the effects on shoot regeneration and ploidy level were evaluated by flow cytometry and chromosome counting. Regeneration and survival rates decreased with increasing colchicine concentration and exposure time. The most effective treatment for autotetraploid induction was 0.1% colchicine for 24 h, yielding a 10.5% polyploidization rate with 5.8% autotetraploids. Tetraploid shoots were successfully rooted (80%) and acclimatized (100%) under greenhouse conditions. Autotetraploid plants exhibited significantly larger and more rounded leaves, higher chlorophyll contents and an increased Chl a/Chl b ratio compared with diploids, indicating enhanced photosynthetic efficiency. The induction of stable autotetraploid lines in A. cherimola provides a reliable approach for generating novel genotypes with improved physiological traits and potential tolerance to abiotic stress. These results offer valuable material for future breeding programs aimed at developing new cherimoya rootstocks and cultivars with enhanced vigor and adaptability. Full article

Early post-germination physiological responses determine oak seedling establishment success under changing environmental conditions. This study investigated four oak species (Quercus cerris, Q. frainetto, Q. petraea, and Q. pubescens) through direct seeding experiments across four locations in Serbia representing varying habitat conditions. Physiological parameters (quantum yield of photosystem II, total stomatal conductance, and leaf vapor pressure deficit) were measured intensively during the first growing season, along with morphological traits and survival rates. Results revealed that microclimatic and soil conditions exerted stronger effects on seedling physiology than species identity, with air humidity, temperature, and soil moisture being primary drivers of photosynthetic performance. Surviving seedlings exhibited 18% higher PhiPSII and 128% higher stomatal conductance compared to non-survivors, demonstrating that physiological performance is a reliable predictor of establishment success. Species-specific differences were evident. Q. cerris and Q. frainetto maintained the highest photosynthetic activity across sites, Q. pubescens showed intermediate resilience, and Q. petraea displayed greater sensitivity to environmental stress. These findings highlight the dominant role of microsite conditions in shaping early seedling physiology and survival. Physiological measurements, particularly PhiPSII and gtw, provide useful early indicators of establishment success during the first growing season following direct seeding. Full article

Active restoration structures such as microtopographic water-harvesting designs are widely implemented in dryland ecosystems to improve soil moisture, reduce erosion, and promote vegetation recovery. We assessed the combined effects of planted species identity, planting diversity (mono-, bi- and multi-species mixtures), and micro-catchment (half-moon) structures on seedling performance and spontaneous natural regeneration in a hyper-arid restoration pilot site in Sharaan National Park, northwest Saudi Arabia. Thirteen native plant species, of which four—Ochradenus baccatus, Haloxylon persicum, Haloxylon salicornicum, and Acacia gerrardii—formed the dominant planted treatments, were established in 18 half-moons and monitored for survival, growth, and natural recruitment. Seedling survival after 20 months differed significantly among planting treatments, increasing from 58% in mono-plantings to 69% in bi-plantings and 82% in multi-plantings (binomial GLMM, p < 0.001), indicating a positive effect of planting diversity on establishment. Growth traits (height, collar diameter, and crown dimensions) were synthesized into an Overall Growth Index (OGI) and an entropy-weighted OGI (EW-OGI). Mixed-effects models revealed strong species effects on both indices (F_12,369 ≈ 7.2, p < 0.001), with O. baccatus and H. persicum outperforming other taxa and cluster analysis separating “fast expanders”, “moderate growers”, and “decliners”. Trait-based modeling showed that lateral crown expansion was the main driver of overall performance, whereas stem thickening and fruit production contributed little. Between 2022 and 2024, half-moon soils exhibited reduced electrical conductivity and exchangeable Na, higher organic carbon, and doubled available P, consistent with emerging positive soil–plant feedbacks. Spontaneous recruits were dominated by perennials (≈67% of richness), with perennial dominance increasing from mono- to multi-plantings, although Shannon diversity differences among treatments were small and non-significant. The correlation between OGI and spontaneous richness was positive but weak (r = 0.29, p = 0.25), yet plots dominated by O. baccatus hosted nearly two additional spontaneous species relative to other plantings, highlighting its strong facilitative role. Overall, our results show that half-moon micro-catchments, especially when combined with functionally diverse native plantings, can simultaneously improve soil properties and promote biotic facilitation, fostering a transition from active intervention to passive, self-sustaining restoration in hyper-arid environments. Full article

The sustainable cultivation of Moringa oleifera is constrained by limited availability of high-quality planting materials. This study established an integrated propagation framework combining seed, cutting, and air-layering methods for the rapid and reliable multiplication of superior genotypes with good morphological traits and elevated astragalin content. Seed pretreatment trials showed that simple soaking for 12 h significantly reduced mean germination time without affecting final germination percentage, while a topsoil–cocopeat–compost mixture enhanced early seedling survival and growth. HPLC profiling identified four genotypes with significantly higher astragalin concentrations (187–281 ppm), linking phytochemical quality with propagation performance. Vegetative propagation experiments revealed that cutting position and girth strongly influenced regeneration success. Cutting position experiments showed clear positional differences, with basal cuttings achieving the highest rooting response. Bottom cuttings produced the highest number of shoots (4.22), nodes (5.00), and thickest shoots (24.65 mm), as well as the highest rooting percentage. Middle cuttings developed the longest shoots (40.21 cm) and the greatest number of roots (32.83), with a rooting percentage of 66.70%. Top cuttings showed the lowest performance across all shoot and root traits. Larger-diameter cuttings produced more shoots but fewer roots while smaller-diameter cuttings produced more roots but fewer shoots. Air-layering with Jiffy-7 pellets achieved the highest root number (43.83) and length (7.23 cm), with 100% survival. Overall, the study provides a robust, mechanism-supported propagation strategy that enables large-scale, uniform production of superior Moringa genotypes, strengthening future programs in clonal improvement, genetic conservation, and sustainable agroforestry development. Full article

(1) Background: ‘Chaling’ common wild rice (CLWR), one of the two wild rice populations with the northernmost natural distribution worldwide, exhibits excellent cold tolerance. The role of microRNA (miRNA) in regulating cold tolerance in plants has been reported in some species. However, the miRNA landscape in CLWR remains unexplored. (2) Methods: We assessed cold tolerance in CLWR and the conventional rice variety 9311 at 4 °C, and conducted small RNA sequencing and analysis on eight samples from both CLWR and 9311, before and after cold treatment. (3) Results: All seedlings of CLWR survived after cold treatment and recovery, while all seedlings of 9311 died. After quality control and classification analysis of the small RNA sequences, numerous known and novel microRNAs (miRNAs) were identified. The expression analysis showed 59 differentially expressed miRNAs in CLWR before and after cold treatment, and 19 in 9311, with eight overlapping differentially expressed miRNAs between the two varieties. Target gene prediction for these miRNAs indicated that some predicted target genes, such as CTB4a and GRF4, are key genes involved in regulating cold tolerance in rice. Additionally, CLWR actively mobilizes more miRNAs and their target genes to resist cold stress than 9311. (4) Conclusions: This study offers new insights into the regulatory mechanisms of cold tolerance in CLWR at the miRNA level, providing a wealth of gene (miRNA) resources for genetic breeding research in rice aimed at enhancing cold tolerance. Full article

Water stress is among the most important abiotic constraints affecting forest ecosystem functioning and regeneration, a phenomenon expected to intensify with climate change. It impacts photosynthesis, growth, and seedling survival, therefore threatening biodiversity and accelerating forest degradation. The use of silicon-based biostimulants has emerged as a way of mitigating the effects of water stress by improving water status and stimulating mechanical and biochemical defense. However, its effectiveness on forest tree species remains poorly explored. This study examines how potassium silicate (PS) alleviates the effects of drought on Canarium madagascariense, with the aim of improving our understanding of the resilience mechanisms of tropical forest species. To do this, an experiment with 135 two-year-old C. madagascariense saplings has been conducted, testing three irrigation levels in combination with the addition of potassium silicate (PS) at concentrations of 5 and 10 mM, via foliar spraying and soil application. Morphometric and physiological parameters were monitored, followed by the biochemical profiling of the induced responses. Linear mixed models were computed to assess the effects of the different factors on the different growth performance, physiological functioning parameters over time, and ANOVA was used for evaluating the punctual data on the biochemical compounds. Drought had a significant impact on the morphological and physiological behaviour of the seedlings. However, the application of PS modified the drought-induced changes, even at a low concentration of 5 mM. Biochemical defenses were also improved further with PS application. Hormone profiling revealed a predominance of auxins, while abscisic acid was lower in the water stress treatments under drought. Therefore, using PS could support the production of robust seedlings that are more tolerant of, and adaptive to, the challenges of climate change, making restoration more efficient. Full article

Seed storage is critical for preserving genetic resources, but optimal long-term storage conditions for Miscanthus seeds have not been established. In this five-year study, we evaluated storage protocols by comparing seed germination after four and five years, along with field establishment performance. The results demonstrated that genotype, storage conditions, and the storage duration all significantly influenced germination percentage and vigor index of Miscanthus seeds. Low temperature storage yielded the highest germination percentage (59.44%) and vigor index (132.06) in the 4th year, while low temperature with desiccant gave the highest germination percentage (42.41%) in the 5th year. The field performance after direct sowing was also significantly influenced by genotype and storage conditions, with the highest seedling survival (7.80%) observed under low temperature with desiccant. The seeds stored under low temperature exhibited minor structural damage, with the intact cell membranes, the small intercellular gaps, and the orderly cell arrangement. Through comprehensive evaluation, storage at −18 °C with desiccant was determined to be optimal. Based on these results, we strongly recommend storing Miscanthus seeds at −18 °C with desiccant. This protocol offers a reliable and effective solution for farmers, seed producers, and storage facilities to ensure long-term seed viability. Full article

In Korea, a persistent shortage of Japanese larch (Larix kaempferi) seeds and the high costs of managing seed orchards have created a significant demand for alternative reforestation methods. This pilot study, conducted over nine years, evaluated the field performance of somatic embryo-derived larch seedlings (emblings) across 14.4 hectares in nine different locations. The study addressed challenges with SE technology, such as limited genetic diversity and the inconsistent quality of seedlings due to year-round production. Despite these initial issues and other environmental interferences, the statistical analysis revealed age to be the sole significant fixed factor driving tree growth and root collar diameter (RCD) increase (p < 0.001 for both). Crucially, the growth rate (slope) for height and RCD was not statistically different between the embling and seed-derived groups (seedlings). Furthermore, the GLMM for survival confirmed that age was not a significant predictor (p > 0.35 for both types). Instead, site-specific factors were the primary drivers of overall survival and growth variation. The random effects analysis showed that site heterogeneity was substantial for height (${\mathit{\sigma }}_{\mathrm{Site}}=0.8256$, indicating that somatic embryo-derived larch plantlets were more sensitive to site-specific environmental conditions than seed-derived seedlings (${\mathit{\sigma }}^2$ was 1.078 for embling survival and 0.4074 for seedling survival). We also found no significant difference in overall tree form or evidence that emblings developed dominant side branches. This research demonstrates that SE technology can produce high-quality larch emblings that are statistically equivalent to their seedling counterparts in long-term growth trajectory and RCD development. It confirms that this method offers a viable and cost-effective solution to Korea’s seed shortage without sacrificing long-term growth or survival. Full article

Regeneration of Pinus brutia (Turkish red pine) after clear-cutting is showing failures in some low-elevation Mediterranean stands, raising questions about long-used silvicultural prescriptions. Because site limitations arise from the combined effects of climate, terrain, and surface thermal conditions that vary over short distances, diagnosing where problems may occur is challenging at operational scales. In this study, we first evaluate the study area (Antalya, Türkiye, 0–400 m elevation band) using open, long-term climatic indicators, along with terrain and surface thermal remote sensing variables, to describe recent environmental conditions relevant to germination and early seedling survival. We then build a transparent environmental-analog screening product that summarizes the degraded reference site as an environmental signature and computes pixel-wise similarity across the landscape at 100 m resolution. The resulting map reports three actionable tiers (≥95th, 90–95th, 85–90th percentiles), delineating compact clusters of very-high analogs surrounded by broader high/elevated belts. Interpreted strictly as a screening layer (not a predictive model), it supports compartment-scale triage: ≥95th areas are first candidates for field checks and adjusted prescriptions, while lower tiers guide targeted site preparation and monitoring. The novelty and importance are practical: widely available Earth observation data are converted into a reproducible, auditable tool that reduces dependence on complex predictive models and large calibration samples, while still requiring careful local interpretation and ground-truthing to inform P. brutia regeneration planning. Full article

Global climate change has intensified land desertification in the arid and semi-arid regions of northwestern China, highlighting the urgent need to cultivate plant species with ideal architecture and well-developed root systems to combat ecosystem degradation. Amorpha fruticosa is widely used as a windbreak and sand-fixation shrub; however, its rapid growth and high transpiration during the early planting stage often result in excessive water loss, low survival rates, and limited vegetation restoration effectiveness. Plant growth retardants (PGRts) are known to suppress apical dominance and promote branching. In this study, one-year-old A. fruticosa seedlings were treated with different combinations of paclobutrazol (PP₃₃₃) and uniconazole (S₃₃₀₇) to investigate their effects on plant morphology and biomass allocation; it aims to determine the optimal formula for cultivating shrub structures with excellent windbreak and sand-fixation effects in land desertification areas. The results showed that both PP₃₃₃ and S₃₃₀₇ significantly inhibited plant height while promoting basal stem diameter, branching, and root development. Among all treatments, the S₃₃₀₇ 200 mg·L⁻¹ + PP₃₃₃ 200 mg·L⁻¹ combination (SD3) was the most effective, resulting in the greatest increases in basal diameter, branch number, total root length, and root-to-shoot ratio, while significantly reducing height increment, leaf length and leaf area (p < 0.05). Under the S₃₃₀₇ 200 mg·L⁻¹ + PP₃₃₃ 300 mg·L⁻¹ treatment (SD4), leaf width and specific leaf area were reduced by 17.92% and 38.89%, respectively, compared with the control. Correlation analysis revealed significant positive or negative relationships among most growth traits, with leaf length negatively correlated with other morphological indicators. Fresh and dry weights of both aboveground and root tissues were significantly positively correlated with basal diameter (R = 0.38) and branch basal diameter (R = 0.33). Principal component analysis demonstrated that the SD3 treatment achieved the highest comprehensive score (2.91), indicating its superiority in promoting a compact yet robust plant architecture. Overall, the SD3 treatment improved drought resistance and sand-fixation capacity of A. fruticosa by “dwarfing and strengthening plants while optimizing root–shoot allocation.” These findings provide theoretical support for large-scale cultivation and vegetation restoration in arid and semi-arid regions and offer a technical reference for growth regulation and windbreak and sand-fixation capacity in other xerophytic shrub species. Full article