Search Results (808)

Tree species are important factors affecting the carbon sequestration capacity of forests and maintaining the stability of ecosystems, but trees are widely distributed spatially and located in complex environments, and there is a lack of large-scale regional tree species classification models for remote sensing imagery. Therefore, many studies aim to solve this problem by combining multivariate remote sensing data and proposing a machine learning model for forest tree species classification. However, satellite-based laser systems find it difficult to meet the needs of regional forest species classification characters, due to their unique footprint sampling method, and SAR data limit the accuracy of species classification, due to the problem of information blending in backscatter coefficients. In this work, we combined Sentinel-1 and Sentinel-2 data to construct a machine learning tree classification model based on optical features, vegetation spectral features, and PolSAR polarization observation features, and propose a forest tree classification feature selection method featuring the Hilbert–Huang transform for the problem of mixed information on the surface of SAR data. The PSO-RF method was used to classify forest species, including four temperate broadleaf forests, namely, aspen (Populus L.), maple (Acer), peach tree (Prunus persica), and apricot tree (Prunus armeniaca L.), and two coniferous forests, namely, Chinese pine (Pinus tabuliformis Carrière) and Mongolian pine (Pinus sylvestris var. mongolica Litv.). In this study, some experiments were conducted using two Sentinel-1 images, four Sentinel-2 images, and 550 measured forest survey sample data points pertaining to the forested area of Fuxin District, Liaoning Province, China. The results show that the fusion model constructed in this study has high accuracy, with a Kappa coefficient of 0.94 and an overall classification accuracy of 95.1%. In addition, this study shows that PolSAR data can play an important role in forest tree species classification. In addition, by applying the Hilbert–Huang transform to PolSAR data, other feature information that interferes with the perceived vertical structure of forests can be suppressed to a certain extent, and its role in the classification of forest species, combined with PolSAR, should not be ignored. Full article

Greenbug, Schizaphis graminum, is one of the important cereal aphid pests of sorghum in the United States and other parts of the world. Sorghum bicolor variety PI 607900 carries the Schizaphis graminum resistance (SgR1) gene that underlies plant resistance to greenbug biotype I (GBI). Now, the SgR1 has been determined as the major gene conferring greenbug resistance based on the strong association of its presence with the resistance phenotype in sorghum. In this study, we have successfully isolated the SgR1 gene using a map-based cloning approach, and subsequent molecular characterization revealed it encodes a leucine-rich repeat containing receptor-like protein (LRR-RLP). According to DNA sequence analysis, the SgR1 gene are conserved among GBI-resistance sorghum accessions but are variable within susceptible lines. Furthermore, an InDel (−965 nt) at its promoter region and a single-nucleotide polymorphism (SNP, 592 nt) in the CDS of the SgR1 were detected and they are well conserved within resistant genotypes. When the SgR1 gene was cloned and transferred into Arabidopsis plants, the SgR1 was activated in the transgenic Arabidopsis plants in response to attack by green peach aphids according to the results of the histochemical assay, and GUS activity was detected in situ in spots around the vasculature of the leaf where the phloem is located, suggesting its biological function in those transgenic Arabidopsis plants. Overall, this study confirms that the SgR1 gene coding for an LRR-RLP is the major resistance gene to greenbug, a destructive pest in sorghum and wheat. This represents the first greenbug resistance gene cloned so far and indicates that the simple-inherited GBI resistance gene can be used for sorghum improvement with genetic resistance to GBI via molecular breeding or cross-based conventional breeding technologies. Full article

In the past, the Silk Road was a vital trade route that spanned Eurasia, connecting East Asia to the Mediterranean Sea. The genus Prunus, belonging to the Rosaceae family and encompassing plums, peaches, apricots, cherries, and almonds, thrived as human travel along the Silk Road increased. The majority of fruits within this genus, whether wild or cultivated, are naturally sweet and easily preserved by drying for storage and transport. The interaction along the Silk Road between wild populations and diverse varieties of Prunus fruits led to the development of various hybrids. This article provides a summary of archaeological findings related to prominent Prunus fruits such as peaches, apricots, plums, cherries, and almonds, shedding light on their evolutionary history, genetic diversity, population structure, and historical dynamics crucial for species conservation. The origins of biodiversity may involve factors like migration of pre-adapted lineages, in situ variation, or the persistence of ancestral lineages. Furthermore, climate change is affecting spatial genetic patterns and potentially further threatening rare Prunus species. Evaluating the scope and composition of genetic diversity within germplasm collections is essential for enhancing plant breeding initiatives and preserving genetic resources in this changing context. From a molecular point of view, techniques such as genome-wide association studies (GWASs) and the identification of quantitative trait loci (QTLs) and genes responsible for phenotypic changes in cultivars and germplasm collections should be of great interest in these breeding programs, while genomic estimated breeding values (GEBVs) derived from genome-wide DNA polymorphism information can facilitate the selection of superior genotypes. Full article

In this study, the salt tolerance of yellow peach varieties (‘Golden gold’) was identified and analyzed in order to determine varieties with excellent resistance. Photosynthetic parameters, the content of Na⁺, K⁺, and malondialdehyde (MDA), the activity of antioxidant enzymes and other physiological indexes of ‘Golden gold’ peaches were measured after the introduction of salt stress using NaCl. The results showed that under salt stress, the stomatal conductance (Gs), net photosynthetic rate (Pn), transpiration ratio (Tr), water utilization ratio (We), activities of photocooperative enzymes (RuBPCase and FBPase), and K⁺ content in the roots and leaves of all varieties decreased, and among these physiological indexes, there was no significant difference between J2+S and the blank control (J). The contents of MDA and proline in J2+S leaves increased the least, so the effect of salt stress was minimal. The superoxide dismutase (SOD) activity, peroxidase (POD) activity, catalase (CAT) activity, and Na⁺ content in the roots and leaves of all ‘Golden gold’ peach varieties increased, and the difference between J2+S and J was significant, with the largest increase. The results of principal component analysis, membership function analysis, and comprehensive evaluation showed that the salt tolerance of nine ‘Golden gold’ peach varieties was ranked as follows: ‘Golden gold’ No. 2 > ‘Golden gold’ No. 5 > ‘Golden gold’ No. 8 > ‘Golden gold’ No. 6 > ‘Golden gold’ No. 1 > ‘Golden gold’ No. 3 > ‘Golden gold’ Parents > ‘Golden gold’ No. 4 > ‘Golden gold’ No. 7. Correlation analysis showed that Pn and We were positively correlated with the D value (p < 0.01), and Tr, SOD, and CAT were also positively correlated with the D value (p < 0.05). Pn, We, Tr, SOD, and CAT can be used as the main reference indexes for screening the salt-tolerant varieties of the ‘Golden gold’ series. Full article

Aiming at many challenges in the recognition task of peach leaf shrink disease, such as the diversity of object size of diseased leaf disease, complex background interference, and inflexible adjustment of model training learning rate, we propose a peach leaf shrink disease recognition algorithm based on an attention generalized efficient layer aggregation network. Firstly, the rectified linear unit activation function is used to effectively improve the stability and performance of the model in low-precision computing environments and solve the problem of partial gradient disappearance. Secondly, the integrated squeeze-and-excitation network attention mechanism can adaptively focus on the key areas of pests and diseases in the image, which significantly enhances the recognition ability of the model to the characteristics of pests and diseases. Finally, combined with fast pyramid pooling enhanced with Local Attention Networks, the deep fusion of cross-layer features is realized to improve the ability of the model to identify complex features and optimize the operation efficiency. The experimental results on the peach leaf shrink disease recognition dataset show that the proposed algorithm achieves a significant improvement in performance compared with the original YOLOv8 algorithm. Specifically, mF1, mPrecision, mRecall, and mAP increased by 0.1075, 0.0723, 0.1224, and 0.1184, respectively, which provided strong technical support for intelligent and automatic monitoring of peach pests and diseases. Full article

Air-assisted sprayers are widely used in orchards due to their efficiency in enhancing droplet penetration and deposition. These sprayers disperse droplets through a high-velocity airflow, which agitates the leaves and aids in canopy penetration. This study involved controlled experiments to simulate leaf movement during field spraying, with a focus on the dynamics of peach tree leaves (Prunus persica) in varying wind fields. An experimental setup consisting of a wind-conveying system, a measurement system, and a fixed system was designed. The moving speeds of the wind field (0.75 m/s, 0.5 m/s, and 1.0 m/s) and wind velocities (ranging from 2 m/s to 8 m/s) were varied. Key parameters, including leaf tip displacement, angular velocity, and twisting amplitude, were measured using high-speed cameras and motion analysis software. The results indicate that, at a constant wind velocity, increasing the wind field’s moving speed resulted in a reduced range of motion, decelerated angular velocity, and decreased twisting amplitude of the leaves. Notably, at a wind field speed of 8 m/s and a moving speed of 1.0 m/s, the twisting duration of the leaves was only 67% of that observed at a moving speed of 0.5 m/s. These findings suggest that wind speed and field motion characteristics play a crucial role in leaf dynamics, informing the design of air-assisted spraying systems. Full article

(1) Background: In drug discovery and pharmaceutical quality control, a challenge is to assess protein extracts used for allergy therapy and in vivo diagnosis, such as prick tests. Indeed, there are significant differences between the features of marketed products due to variations in raw materials, purification processes, and formulation techniques. (2) Methods: A protein array technology has been developed to provide comprehensive information on protein–biomarker interactions on a large scale to support the pharmaceutical industry and clinical research. The biosensing method is based on immobilizing low volumes of protein extracts (40 nL) on thermoplastic chips in array format. The biological activity was estimated by incubating with serum from representative food allergy patients. (3) Results: The reproducible optical signals were registered (deviation lower than 10%) using low-cost technologies such as a smartphone and a reader of digital versatile discs. The method was applied to pharmaceutical products to diagnose ten common food allergies, including barley, kiwi, milk, prawn, egg, peanut, wheat, peach, walnut, and squid. Quality indicators were established from spot intensities, enabling an effective comparison of manufacturers. (4) Conclusions: A biosensing-based strategy for screening pharmaceutical products emerges as a reliable and advantageous alternative to traditional approaches such as electrophoresis, fluorescence chips, and ELISA assays. This high-throughput method can contribute to understanding complex biological processes and evaluate the performance of pharmaceutical products. Full article

During the dormant period of peach trees in winter, flower buds exhibit weak cold resistance and are susceptible to freezing at low temperatures. Understanding the physiological and molecular mechanisms underlying the response of local peach buds to low-temperature adversity is crucial for ensuring normal flowering, fruiting, and yield. In this study, the experimental materials included the conventional cultivar ‘Xia cui’ (XC) and the cold-resistant local resources ‘Ding jiaba’ (DJB) peach buds. The antioxidant enzyme activity, levels of malondialdehyde (MDA), proline (Pro), and hydrogen peroxide content (H₂O₂) were determined in peach buds at different dormancy periods. Transcriptome sequencing was performed at three dormancy stages: the dormancy entry stage (FD), deep dormancy release stage (MD), and dormancy release stage (RD). Additionally, transcriptome sequencing was conducted to analyze gene expression profiles during these stages. Our findings revealed that compared with XC cultivars, DJB peach buds exhibited decreased MDA and H₂O₂ contents but increased superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities as well as Pro content during the dormancy period. These findings suggest that cold-resistant cultivars possess significantly stronger antioxidant capacity than conventional cultivars under low-temperature stress. A total of 10,168 differential genes were annotated through transcriptome sequencing. Among them, 4975 were up-regulated while 5193 were down-regulated. The differentially expressed genes associated with low-temperature response in peach buds are primarily enriched in plant hormone signal transduction pathway and phenylpropane synthesis pathway. Key differentially expressed genes related to cold resistance include ARF2, GH3, and SAPK2, and differentially expressed transcription factors mainly belong to the AP2/ERF-ERF, bHLH, and C2H2 families. This study provides a theoretical foundation for understanding the key genes involved. Full article

The green peach aphid (Myzus persicae) is a generalist pest damaging crops and transmitting viral pathogens. Using Illumina sequencing of small (s)RNAs and poly(A)-enriched long RNAs, we analyzed aphid virome components, viral gene expression and antiviral RNA interference (RNAi) responses. Myzus persicae densovirus (family Parvoviridae), a single-stranded (ss)DNA virus persisting in the aphid population, produced 22 nucleotide sRNAs from both strands of the entire genome, including 5′- and 3′-inverted terminal repeats. These sRNAs likely represent Dicer-dependent small interfering (si)RNAs, whose double-stranded RNA precursors are produced by readthrough transcription beyond poly(A) signals of the converging leftward and rightward transcription units, mapped here with Illumina reads. Additionally, the densovirus produced 26–28 nucleotide sRNAs, comprising those enriched in 5′-terminal uridine and mostly derived from readthrough transcripts and those enriched in adenosine at position 10 from their 5′-end and mostly derived from viral mRNAs. These sRNAs likely represent PIWI-interacting RNAs generated by a ping-pong mechanism. A novel ssRNA virus, reconstructed from sRNAs and classified into the family Flaviviridae, co-persisted with the densovirus and produced 22 nucleotide siRNAs from the entire genome. Aphids fed on plants versus artificial diets exhibited distinct RNAi responses affecting densovirus transcription and flavivirus subgenomic RNA production. In aphids vectoring turnip yellows virus (family Solemoviridae), a complete virus genome was reconstituted from 21, 22 and 24 nucleotide viral siRNAs likely acquired with plant phloem sap. Collectively, deep-sequencing analysis allowed for the identification and de novo reconstruction of M. persicae virome components and uncovered RNAi mechanisms regulating viral gene expression and replication. Full article

Background/Objectives: The sucrose non-fermentation-related kinase 1 (SnRK1) protein complex in plants plays an important role in energy metabolism, anabolism, growth, and stress resistance. SnRK1 is a heterotrimeric complex. The SnRK1 complex is mainly composed of α, β, βγ, and γ subunits. Studies on plant SnRK1 have primarily focused on the functional α subunit, with the β regulatory subunit remaining relatively unexplored. The present study aimed to elucidate the evolutionary relationship, structural prediction, and interaction with the core α subunit of peach SnRK1β3 (PpSnRK1) subunit. Methods: Bioinformatics analysis of PpSnRK1 was performed through software and website. We produced transgenic tomato plants overexpressing PpSnRK1 (OEPpSnRK1). Transcriptome analysis was performed on OEPpSnRK1 tomatoes. We mainly tested the growth index and drought resistance of transgenic tomato plants. Results: The results showed that PpSnRK1 has a 354 bp encoded protein sequence (cds), which is mainly located in the nucleus and cell membrane. Phylogenetic tree analysis showed that PpSnRK1β3 has similar domains to other woody plants. Transcriptome analysis of OEPpSnRK1β3 showed that PpSnRK1β3 is widely involved in biosynthetic and metabolic processes. Functional analyses of these transgenic plants revealed prolonged growth periods, enhanced growth potential, improved photosynthetic activity, and superior drought stress tolerance. Conclusions: The study findings provide insight into the function of the PpSnRK1 subunit and its potential role in regulating plant growth and drought responses. This comprehensive analysis of PpSnRK1 will contribute to further enhancing our understanding of the plant SnRK1 protein complex. Full article

Peach (Prunus persica) is widely cultivated in China, but fungal diseases, particularly Cytospora canker, significantly impact tree health, reducing fruit yield and economic value. This disease mainly weakens tree branches and trunks, sometimes leading to tree death. There are no updated studies on the diversity of Cytospora species associated with peach Cytospora canker in northern China. To determine the Cytospora species associated with this disease, we surveyed five provinces from 2022 to 2023, collecting 72 disease samples with symptoms including branches with black fruiting bodies, cankers, cracking, dieback, and gummosis. Through morphology and multi-loci phylogeny, 127 isolates were identified into four known (C. ailanthicola, C. erumpens, C. leucostoma, and C. leucosperma) and two previously undescribed species (C. gansuensis sp. nov. and C. qinanensis sp. nov.). Cytospora leucostoma (73.60%) was the most abundant. Pathogenicity tests indicated that except for C. ailanthicola, all other species were pathogenic to peach, with C. erumpens being the most aggressive. This study is the first to report the novel host association of C. erumpens on peaches globally and represents the first comprehensive investigation of Cytospora species associated with canker diseases in the main peach production area in northern China, offering a foundation for developing effective disease management strategies. Full article

Plant diseases diminish crop yields and put the world’s food supply at risk. Plant elicitor peptides (Peps) are innate danger signals inducing defense responses both naturally and after external application onto plants. Pep-triggered defense networks are compatible with pattern-triggered immunity (PTI). Nevertheless, in complex regulatory pathways, there is crosstalk among different signaling pathways, involving noncoding RNAs in the natural response to pathogen attack. Here, we used Prunus persica, PpPep2 and a miRNA-Seq approach to show for the first time that Peps regulate, in parallel with a set of protein-coding genes, a set of plant miRNAs (~15%). Some PpPep2-regulated miRNAs have been described to participate in the response to pathogens in various plant–pathogen systems. In addition, numerous predicted target mRNAs of PpPep2-regulated miRNAs are themselves regulated by PpPep2 in peach trees. As an example, peach miRNA156 and miRNA390 probably have a role in plant development regulation under stress conditions, while others, such as miRNA482 and miRNA395, would be involved in the regulation of resistance (R) genes and sulfate-mediated protection against oxygen free radicals, respectively. This adds to the established role of Peps in triggering plant defense systems by incorporating the miRNA regulatory network and to the possible use of Peps as sustainable phytosanitary products. Full article

Peach bud differentiation is commercially significant for fruit production. Bud differentiation in peach production is closely linked to chilling requirements. This study investigates the mechanisms of flower bud differentiation in peach varieties L12 and N1 under varying chilling requirements by comparing paraffin sections, hormone content changes, and transcriptomes during four chilling hours and the same physiological stage. At 400 chilling hours, significant changes in flower bud differentiation were observed. During this period, the hormone levels of auxin and gibberellin reached their peak, while abscisic acid levels were at their lowest. This finding indicates that 400 chilling hours has a significant regulatory effect on flower bud development. Transcriptome analysis revealed that 4719 differentially expressed genes were identified in the flower bud differentiation of L12-4 and N1-4, and 2717 differentially expressed genes of L12-8 and N1-2, many of which are involved in IAA, GA, and ABA signal transduction pathways. In N1, the differentially expressed genes AUX/IAA, SAUR, and DELLA were significantly higher than in L12, whereas genes associated with the ABA synthesis pathway, such as PYL2, PYL8, and SRK2A, remained at the lowest level. This study provides a crucial molecular basis for understanding the regulation of plant hormones and their effects on flower bud development under varying chilling hours. Full article

Xylella fastidiosa is an aerobic, Gram-negative bacterium that is responsible for many plant diseases. The bacterium is the causal agent of Pierce’s disease in grapes and is also responsible for citrus variegated chlorosis, peach phony disease, olive quick decline syndrome and leaf scorches of various species. The production of biofilm is intrinsically linked with persistence and transmission in X. fastidiosa. Biofilm formation is regulated by members of the Diffusible Signal Factor (DSF) quorum sensing signalling family which are comprised of a series of long chain cis-unsaturated fatty acids. This article describes the evaluation of a library of N-acyl sulfonamide bioisosteric analogues of BDSF, XfDSF1 and XfDSF2 for their ability to control biofilm production in X. fastidiosa. The compounds were screened against both the wild-type strain Temecula and an rpfF* mutant which can perceive but not produce XfDSF. Planktonic cell abundance was measured via OD600 while standard crystal violet assays were used to determine biofilm biomass. Several compounds were found to be effective biofilm inhibitors depending on the nature of the sulfonamide substituent. The findings reported here may provide future opportunities for biocontrol of this important plant pathogen. Full article

(1) Background: Genistein is a naturally occurring flavonoid with a rich spectrum of biological activities, including plant-herbivore interactions. The aim of the study was to evaluate the effect of exogenous application of genistein on aphid behavior during probing in plant tissues. (2) Methods: Vicia faba, Brassica rapa ssp. pekinensis, and Avena sativa were treated transepidermally with a 0.1% ethanolic solution of genistein, and the probing behavior of generalist aphid species Aphis fabae, Myzus persicae, and Rhopalosiphum padi was monitored on their respective treated and untreated host plants using electropenetrography (=electrical penetration graph technique, EPG); (3) Results: Genistein did not deter aphid probing activities in non-phloem tissues. In A. fabae and R. padi, a trend towards reduction and in M. persicae a trend towards increase in phloem sap ingestion occurred on genistein-treated plants, but these trends were not statistically significant. (4) Conclusions: Genistein is not a deterrent chemical against generalist aphid species studied; therefore, it is not recommended for practical application. Full article