Search Results (257)

To identify the root-knot nematodes (RKNs) infecting onions in Yuanmou County, Yunnan Province, morphological and molecular biological techniques were used. Observation of their life cycle and pathogenicity was conducted through artificial inoculation experiments in a greenhouse. The results show that the morphological characteristics and measurement data of the second-stage juveniles (J2s) and females of RKNs infecting onion roots are highly consistent with those of Meloidogyne graminicola (M. graminicola). Sequence alignment of the mitochondrial DNA (mtDNA) COXI region and 28S rDNA D2-D3 region revealed sequence similarities of 99.51–100.00% and 99.48–99.61%, respectively, compared with M. graminicola sequences from GenBank. The specific primers Mg-F3/Mg-R2 reliably amplified a characteristic 369 bp band. Inoculation experiments confirmed that the pathogen can complete its entire life cycle (approximately 26 days (ds)) on the roots of healthy onion seedlings, inducing typical root-knot symptoms and females. In conclusion, the pathogen was identified as M. graminicola, which is the first report of M. graminicola infecting onions in China. This study provides important theoretical support for the molecular diagnosis of onion root-knot nematode disease and the green control of Allium L. vegetables in China. Full article

The ecosystem services (ESs) of forests are the benefits that people derive from forest ecosystems. Their precise recognition is important for differentiating and determining the optimal principles of multifunctional forest management. The aim of this study is to identify some important ESs based on a site classification system at the lowest level—i.e., forest stands, at the forest owner level—as a tool for differentiated management. ESs were assessed within the Czech Republic and are expressed in units in accordance with the very sophisticated Forest Site Classification System. (1) Biomass production: The vertical differentiation of ecological conditions given by vegetation tiers, which reflect the influence of altitude, exposure, and climate, provides a basic overview of biomass production; the highest value is in the fourth vegetation tier, i.e., the Fageta abietis community. Forest stands are able to reach a stock of up to 900–1200 m³·ha⁻¹. The lowest production is found in the eighth vegetation tier, i.e., the Piceeta community, with a wood volume of 150–280 m³·ha⁻¹. (2) Soil conservation function: Geological bedrock, soil characteristics, and the geomorphological shape of the terrain determine which habitats serve a soil conservation function according to forest type sets. (3) The hydricity of the site, depending on the soil type, determines the hydric-water protection function of forest stands. Currently, protective forests occupy 53,629 ha in the Czech Republic; however, two subcategories of protective forests—exceptionally unfavorable locations and natural alpine spruce communities below the forest line—potentially account for 87,578 ha and 15,277 ha, respectively. Forests with an increased soil protection function—a subcategory of special-purpose forests—occupy 133,699 ha. The potential area of soil protection forests could be up to 188,997 ha. Water resource protection zones of the first degree—another subcategory of special-purpose forests—occupy 8092 ha, and there is potentially 289,973 ha of forests serving a water protection function (specifically, a water management function) in the Czech Republic. A separate subcategory of water protection with a bank protection function accounts for 80,529 ha. A completely new approach is presented for practical use by forest owners: based on the characteristics of the habitat, they can obtain information about the fulfillment of the habitat’s ecosystem services and, thus, have basic information for the determination of forest categories and the principles of differentiated management. Full article

Winter squash (Cucurbita moschata Duchesne.) is a vegetable of high socioeconomic importance owing to the nutritional quality of its fruits, seeds, and seed oil. This study aims to review the main aspects related to the characterization, conservation, and breeding of C. moschata, emphasizing the studies with C. moschata accessions maintained by the Vegetable Germplasm Bank of the Federal University of Viçosa (BGH-UFV). Studies on C. moschata germplasm have reported high variability, particularly in Brazil. Currently, Brazil maintains six Cucurbita germplasm collections, kept in research and teaching institutions. The BGH-UFV collection, one of the largest in the country, contains approximately 350 accessions of C. moschata, mostly landraces collected from all over Brazil. Studies characterizing this germplasm have identified promising genotypes as sources of alleles for increasing the carotenoid content in the fruit pulp and oleic acid content in the seed oil. As part of a breeding program to increase seed oil productivity and improve the oil profile, studies with the BGH-UFV germplasm have identified C. moschata genotypes with seed oil productivity of up to 0.27 t ha⁻¹ and accessions producing oil with high oleic acid content (21 to 28%). The genetic breeding program of C. moschata conducted at the UFV has prioritized the development of compact growth habit genotypes to reduce plant spacing and increase seed and oil productivity. The works involving the collection of C. moschata maintained by the BGH-UFV corroborates the importance of this germplasm as a source of alleles for improving seed oil productivity and the oil profile. Full article

Belowground buds play a vital role in the clonal propagation and structural regulation of perennial herbaceous plants, especially in alpine environments, where vegetative renewal depends heavily on bud bank dynamics. However, the interactive effects of nitrogen addition and phenological stages on bud development and aboveground branching remain poorly understood. In this study, we examined the responses of rhizome buds, tiller buds, and aboveground tiller types of Kentucky bluegrass to six nitrogen levels (0, 6, 9, 12, 15, and 18 g/m²) across five growth stages on the Qinghai–Tibet Plateau. The results showed that moderate nitrogen input (N2, 9 g/m²) significantly enhanced total bud density, particularly at the heading and maturity stages, indicating a threshold response. Aboveground reproductive tiller density peaked at N2 (9 g/m²), while vegetative and total tiller densities plateaued beyond N3 (12 g/hm²), suggesting a diminishing marginal effect of nitrogen on aboveground tiller density. Furthermore, bud density showed stage-specific correlations with tiller types: vegetative tillers were primarily influenced at the heading stage, and reproductive tillers were mainly influenced at the mature stage, with weakened associations in senescence. These findings highlight the phenological specificity and non-linear response of clonal grass regeneration to nitrogen input and provide a theoretical basis for optimizing nutrient management in cold alpine grasslands. Full article

Spinach (Spinacia oleracea L.) is an important leafy vegetable but is vulnerable to viral infections that significantly affect its quality and yield. In this study, we identified virus-infected spinach exhibiting typical symptoms with yellowing, wrinkling, and mottling in Beijing. But conventional RT-PCR screening for twelve common plant viruses yielded negative results. Then, using transcriptome sequencing along with a de novo assembly approach, we obtained the complete viral genome, which consists of RNA1 (5916 nucleotides) and RNA2 (3576 nucleotides). BLASTN analysis against the NCBI viral genome database revealed high homology with broad bean wilt virus 2 (BBWV2), leading us to designate this isolate as BBWV2-SP (GenBank accession numbers PV102464 and PV102465). Phylogenetic analysis indicated that BBWV2-SP shares 96.69% nucleotide sequence identity with a Liaoning isolate from Chenopodium album MN786955 and clusters within the Chinese evolutionary lineage. We developed primers targeting the conserved region of the RNA2 coat protein, amplifying a 478-base-pair product. All symptomatic spinach samples tested positive, while asymptomatic controls remained negative, confirming the causal relationship between BBWV2-SP and the observed disease symptoms. This study provides the complete genome assembly of the spinach isolate BBWV2-SP and establishes a molecular detection protocol for BBWV2 in spinach. These findings offer essential technical support for field monitoring, epidemiological surveillance, and disease control strategies, while also enhancing our understanding of BBWV2′s genetic diversity and mechanisms of pathogenicity. Full article

Adequate and diverse diets are essential for children’s physical and cognitive development, yet food insecurity and malnutrition continue to threaten this fundamental right, which remains a pressing concern in many resource-poor settings. This study investigated food and nutrition security in Early Childhood Development (ECD) centres in Makhanda, South Africa, through a community-based participatory research approach. Using a mixed-methods approach combining questionnaire interviews, focus group discussions, direct observations, and community asset mapping across eight ECD centres enrolling 307 children aged 0–5 years, the study engaged ECD facilitators and analysed dietary practices across these centres. Results indicated that financial constraints severely affect the quality and diversity of food provided at the centres, thus undermining the ability to provide nutritionally adequate meals. The average amount spent on food per child per month at the centres was R90 ± R25 (South African Rand). Although three meals were generally offered daily, cost-driven dietary substitutions with cheaper, less diverse alternatives, often at the expense of nutritional value, were common. Despite guidance from Department of Health dieticians, financial limitations contributed to suboptimal feeding practices, with diets dominated by grains and starchy foods, with limited access to and rare consumption of protein-rich foods, dairy, and vitamin A-rich fruits and vegetables. ECD facilitators noted insufficient parental contributions and low engagement in supporting centre operations and child nutrition provision, indicating a gap in awareness and limited nutrition knowledge regarding optimal infant and young child feeding (IYCF) practices. The findings emphasise the need for sustainable, multi-level and community-led interventions, including food gardening, creating ECD centre food banks, parental nutrition education programmes, and enhanced financial literacy among ECD facilitators. Strengthening local food systems and establishing collaborative partnerships with communities and policymakers are essential to improve the nutritional environment in ECD settings. Similarly, enhanced government support mechanisms and policy-level reforms are critical to ensure that children in resource-poor areas receive adequate nutrition. Future research should focus on scalable, locally anchored models for sustainable child nutrition interventions that are contextually grounded, community-driven, and should strengthen the resilience of ECD centres in South Africa. Full article

Estimating bed load in rivers is a critical aspect of river engineering. Numerous methods have been developed to quantify bed load transport, often yielding varying results depending on the bed surface texture and grain size. This study aims to investigate how vegetation on channel banks and bed material particle size influence bed load transport, bed shear stress, velocity distribution, and the Shields parameter. It also examines the impact of geometric changes in the channel cross-section on bed load transport capacity. To address these objectives, a novel simulation method was developed to analyze the effects of vegetated banks, bed material size, and channel geometry. Field investigations were carried out in two reaches of the Taleghan River in Iran—one with vegetated banks and one without. Complementary flume experiments were conducted at two scales, incorporating vegetation on the sidewalls. Results showed that Shields parameter distribution corresponded with bed load distribution across cross-sections. Increase in flow rate and the Shields parameter led to higher bedload transport rates. Near vegetated banks, flow velocity, shear stress, and bedload transport were significantly reduced, with velocity profiles showing distinct variations compared to non-vegetated sections. Full article

The genus Musa L. is one of the most important genera worldwide due to its use in food as a source of carbohydrates. A morphological characterization was performed to evaluate the potential of 100 accessions of Musa spp. from the Amazon region of Ecuador, applying 73 qualitative and quantitative descriptors in addition to the ecogeographic characterization. The multivariate analyses identified four large groups: The first is composed of the Musa AAB Simmonds ecotype “Hartón Plantain” and the “Cuerno Clone”. The second group is composed of the Musa acuminata Colla ecotype “Orito”. The third group is composed of the Musa acuminata ecotype “Malay plantain or red plantain”; and the fourth group is composed of the Musa × paradisiaca L. AAB ecotype “Barraganete” and banana or banana materials and the Musa AAB Simmonds ecotype “Plátano Dominico”. The qualitative descriptors with the highest discriminant value were the shape of the ♂ floret bud, the appearance of the rachis, and the pigmentation of the compound tepal, and the quantitative discriminant characters were the height of the pseudostem, the length of the leaf blade, the width of the leaf blade, and the weight of the raceme. The analysis with CAPFITOGEN of these 100 accessions through the ecogeographic characterization map identified 23 categories, highlighting category 20 with a coverage of 40.35%, which mainly includes the provinces of Orellana, Sucumbíos, part of Napo, Pastaza, and Morona Santiago. This category occurs within an annual temperature range between 21.6 °C and 27 °C, an apparent density of 1.25 to 1.44 g cm⁻³, and a cation exchange capacity (CEC) of 4 to 29 Cmol kg⁻¹. The morphological characterization of 100 Musa accessions revealed significant phenotypic variability, with four distinct morphological groups identified through cluster analysis. Key differences were observed in traits such as bunch weight, fruit length, and vegetative vigor. This variability highlights the potential of certain accessions for use in genetic improvement programs. The findings contribute valuable information for the efficient conservation, selection, and utilization of the Musa germplasm in Ecuadorian agroecosystems. The results demonstrate the existence of an important genetic variability in the INIAP Musa Germplasm Bank in the Ecuadorian Amazon region. Full article

The EAT-Lancet diet outlines target consumption for specific food components but overlooks accessibility and cost issues, which may hinder adherence among vulnerable populations. This study examines the acquisition profile of EAT-Lancet diet components by food security and poverty status, using data from 57,920 households in the 2017–2018 Brazilian Household Budget Survey. Poverty and food insecurity were defined according to the World Bank per capita income cutoffs and the Brazilian Food Insecurity Scale, respectively. Food acquisition was classified into 15 EAT-Lancet diet components and expressed as per capita daily averages (g, % of total available energy, and % of food expenditure), by food security and poverty strata. Brazilian households were 37.9% food-insecure and 12% poor. Compared to more privileged counterparts, these households prioritized the acquisition of staples like refined cereals and legumes over most EAT-Lancet diet adequacy components, such as fruits, vegetables, whole grains, nuts, and peanuts. While lower energy shares from moderation components were only slightly evident for red meat and dairy among food-insecure households, pronounced reductions in added sugars and vegetable oils were seen among the poor. These findings suggest that public policies should synergically address particularities of different deprivation contexts to promote sustainable diets in Brazil. Full article

In Greece, water scarcity is a key factor limiting forest growth, with a strong correlation observed between water availability and tree ring growth in Mediterranean forests. The LIFE-PRIMED project in the Nestos Delta, northeastern Greece, studied tree growth patterns on both riverbanks, noting significant fluctuations towards the east and varying increases towards the west. The drought index revealed a decrease in drought over time, and no clear link between tree growth and drought conditions was found. Severe droughts and dam-induced flooding appear to affect tree growth by altering hydrological patterns. Years of significant decline with notable growth deviations include 1995, 1998, 2000, 2002, 2007, and 2017 in the eastern region, and 2002, 2004, 2007, and 2017 in the western region. Significant droughts in 1990, 1993, and 2001 had limited immediate impact but may have affected growth in subsequent years. Further research is needed to understand the impact of climatic conditions and prolonged floods on tree growth to improve management decisions. Full article

Understanding the characteristics and key driving factors of plant diversity is of great significance for maintaining biodiversity and the ecosystem. Current studies on plant diversity in the Yellow River Delta are limited to local areas; there is a lack of comprehensive discussion on the spatial heterogeneity of plant diversity and the driving factors at a regional scale. Based on field investigations, this study explored the characteristics of plant composition and diversity under the land–sea gradient, with particular emphasis on the differences of plant diversity under different riverbanks and at a distance from the sea. Using the regression, redundancy, and Mantel test analysis, we analyzed soil properties, environmental factors, and human influence to assess their potential impacts on plant diversity. The results demonstrated that Asteraceae, Poaceae, and Amaranthaceae are the dominant plant families in the Yellow River Delta. As the distance from the sea increases, the community transitions from the monospecies dominance of Suaeda salsa to one dominated by various plants. The species similarity was higher in the adjacent environment and coastal areas. The overall level of plant diversity was not high, and the Margalef, Shannon–Wiener, Simpson, and Pielou index showed a fluctuating downward trend from land to sea. Notably, there was a peak value in the region of 3–17 km and >42 km from the sea. The plant diversity of the main stream bank was higher than that of its tributaries, where the former was more susceptible to human interference and the latter to soil electrical conductivity. In terms of the region, soil electrical conductivity had the greatest influence on plant diversity. This study could provide theoretical support for vegetation restoration and ecological protection in the Yellow River Delta. Full article

The interaction between curvature-induced flow and vegetation plays a crucial role in regulating threshold velocity, influencing sediment transport dynamics. This experimental study investigates the effects of flow velocity and turbulence, induced by both emergent vegetation and curvature-driven flow, on the threshold of sediment motion around a vegetated patch. Using an Acoustic Doppler Velocimeter (ADV), a total of 504 velocity profiles were collected under vegetated and non-vegetated conditions, considering a range of vegetation densities (φ = 0.001–0.0099) in both a straight channel and a 180-degree bend. The results indicate that vegetation modifies turbulent kinetic energy (TKE) and velocity gradients, thereby enhancing sediment mobility. Specifically, vegetation significantly reduces maximum velocity by up to 37%, shifting the flow core to the center and enhancing TKE by up to 30 times. This analysis shows that channel curvature contributes a maximum of 34% and 17% to turbulent kinetic energy in the first and second halves of a 180-degree bend, respectively. Turbulence from the bed and vegetation accounts for 50% in straight paths, while in curved paths, it reaches 37% and 32% in the first half and 48% and 42% in the second half of a 180-degree bend. This study proposes a model for turbulent kinetic energy (k_t) that incorporates velocity threshold constraints, validated through controlled laboratory experiments, highlighting the role of near-bed turbulence in modulating sediment transport. Furthermore, the findings demonstrate that sediment motion initiation is governed by both mean flow velocity and TKE, leading to the introduction of a novel criterion for assessing initial sediment transport conditions in curved and vegetated flows. Full article

Although low-head dams in the USA provide water supply, irrigation, and recreation opportunities, many are unknown by regulators. Unfortunately, hundreds of drownings occur each decade at these dams from an entrapment current that can form immediately downstream. To explore the ability of deep learning to scan large areas of terrain to identify the locations of low-head dams, ArcGIS Pro and embedded deep learning models for object-based image analysis were investigated. The State of Indiana low-head dam dataset was selected for model training and validation. Aerial imagery (leaf-off conditions) captured from 2016 to 2018 for the nearly 94,000 km² area had a minimum resolution of 304.8 mm. A new Python code was developed that automated the generation of training images and searching was limited to 100 m wide river corridors. Due to bank vegetation, all low-head dams were assigned a visibility score to aid in training and performance analysis. A total of 19 backbone models were considered with single shot detection and options for RetinaNet, Faster R-CNN, and batch normalization. Additional identification classes were incorporated to overcome identification of visually similar objects. After four training iterations, the final trained model was a ResNet RetinaNet backbone model featuring 101 layers with an 83% recall rate for dams with high visibility and a 17% recall rate for those with moderate visibility. Full article

Soil salinisation is a critical problem in northern China’s arid and semi-arid irrigated regions, posing a substantial impediment to the sustainable advancement of agriculture in these areas. This research utilises the Donghaixin Irrigation District, located on the southern bank of the Yellow River in Inner Mongolia, as a case study. This study examines the spatial distribution and determinants of soil salinisation through macro-environmental variables and micro-ion composition, integrating regression models and groundwater ion characteristics to elucidate the patterns and causes of soil salinisation systematically. The findings demonstrate that soil salinisation in the study region displays notable spatial clustering, with surface water-irrigated regions exhibiting greater salinisation levels than groundwater-irrigated areas. More than 80% of the land exhibits moderate salinity, predominantly characterised by the ions Cl⁻, HCO₃⁻, and SO₄²⁻. The hierarchy of ion concentration variation with escalating soil salinity is as follows: Na⁺ > K⁺ > SO₄²⁻ > Cl⁻ > Mg²⁺ > HCO₃⁻ + CO₃²⁻ > Ca²⁺. The susceptibility of ions to soil salinisation is ordered as follows: Ca²⁺ > Na⁺ > HCO₃⁻ + CO₃²⁻ > Mg²⁺ > K⁺ > Cl⁻ > SO₄²⁻. In contrast to the ordinary least squares (OLS) model, the geographic weighted regression (GWR) model more effectively elucidates the geographical variability of salinity, evidenced by an adjusted R² of 0.68, particularly in high-salinity regions, where it more precisely captures the trend of observed values. Ecological driving elements such as organic matter (OM), pH, groundwater depth (GD), total dissolved solids (TDS), digital elevation model (DEM), normalised difference vegetation index (NDVI), soil moisture (SM), and potential evapotranspiration (PET) govern the distribution of salinisation. In contrast, anthropogenic activities affect the extent of salinisation variation. Piper’s trilinear diagram demonstrates that Na cations mainly characterise groundwater and soil water chemistry. In areas irrigated by surface water, the concentration of SO₄²⁻ is substantially elevated and significantly affected by agricultural practises; conversely, in groundwater-irrigated regions, Cl⁻ and HCO₃⁻ are more concentrated, primarily driven by evaporation and ion exchange mechanisms. Full article

Evapotranspiration (ET) rates will be affected by climate change and increasing frequency of extreme heat events. To understand how forests may respond to probable future climate conditions, it may be helpful to look at the past relationship between climate and ET. This can be accomplished using satellite imagery since the 1980s, but prior to that, a different approach is required. Using a global ET dataset (1982 to 2010) with 1 km resolution, climate station information from 1850 to 2010, and 54 tree-ring plots from the International Tree-Ring Data Bank (ITRDB) database, ET reconstructions were developed for each vegetated pixel with point-by-point regressions in British Columbia. ET was estimated for the province of British Columbia in Canada from 1850 to 1981, using random forest, support vector machine, and convolutional neural network regressions. ET satellite images from 1982 to 2010 formed our dataset to train models for each vegetated pixel. The random forest regression outperformed the other approaches with lower errors and better robustness (adjusted R² value = 0.69; root mean square error = 10.72 mm/month). Modeled findings indicate that ET rates are generally increasing in British Columbia (ET = 0.0064 × Year + 52.339), but there were regional effects on local ET, as only the Humid Temperate ecodomain had strong correlations of ET with mean summer temperature (r = 0.257, p < 0.01) and mean summer precipitation (r = −0.208, p < 0.05). These historical estimates provide an opportunity to observe spatiotemporal variation in ET across British Columbia and elsewhere. Full article