Tomato viral diseases have been identified as one of the key factors constraining the development of the tomato cultivation industry in Jiuquan City, Gansu Province. In this study, viral pathogens were identified using small RNA sequencing combined with reverse transcription-polymerase chain reaction (RT-PCR) technology in tomato samples collected from this region. The results showed that three main viral pathogens infecting tomatoes in Jiuquan City were identified: tomato mosaic virus (ToMV), tomato brown rugose fruit virus (ToBRFV), and southern tomato virus (STV). Field surveys conducted in 2025 revealed that the field symptoms of tomato viral diseases included four symptom types: mottled mosaic, reticulated mosaic, leaf malformation and asymptomatic, among which mosaic symptoms were the most prevalent. RT-PCR analysis of 135 samples collected from the field in 2025 showed that the total detection rate for ToMV, ToBRFV and STV was 82.96%, with average detection rates of 52.59%, 56.29% and 42.22%, respectively. A correlation was observed between symptom types and viral pathogen infection. Within the same symptom type, increased symptom severity was associated with elevated virus detection rates, co-infection rates, and relative expression of viral CP gene of each virus also increased. Co-infections were predominant, with a co-infection rate of 51.11%, which was 19.26% higher than the rate of single infections. Four co-infection types were detected: ToMV+ToBRFV+STV, ToMV+ToBRFV, ToMV+STV and ToBRFV+STV, with infection rates from high to low of 17.04%, 16.30%, 8.89% and 8.89%, respectively. In samples with severe mottled mosaic symptoms, the relative expression of ToMV-CP, ToBRFV-CP and STV-CP were 1.72, 3.00 and 2.59 folds higher, respectively, than those in samples with mild mosaic symptoms. The findings are important for clarifying the viral species and co-infection status in Gansu Province, preliminarily elucidating the detection rates of different viruses and the relative expression of their CP in tomato samples with various symptom types, and revealing the correlations among symptom presentation, viral pathogen identity and viral CP expression. A scientific basis has been provided for effective monitoring and control against tomato viral diseases.

Gentiana crassicaulis Duthie ex Burk., Aucklandia lappa Decne., Platycodon grandiflorum (Jacq) A. DC., Aconitum carmichaeli Debx. and other medicinal plants are widely planted in Ludian Township, Yulong County, Lijiang City, Yunnan Province. They are all damaged by Meloidogyne spp.. In this study, the incidence and disease index of root-knot nematode disease of four medicinal plants in Ludian Township were investigated, and the pathogenic species of root-knot nematode disease of medicinal plants were identified by morphological and molecular biological methods. The occurrence status and pathogenic nematode species of root-knot nematode disease of main medicinal plants in Ludian Township were clarified. The incidence of root-knot nematode disease of Gentiana crassicaulis, Aucklandia lappa, Platycodon grandiflorum and Aconitum carmichaelii in Ludian Township of Lijiang City was 84.30%, 83.87%, 71.43% and 77.11%, respectively, and the disease index was 34.36, 26.88, 12.71 and 20.48, respectively. The pathogenic nematodes of the four medicinal plants were Meloidogyne hapla. The precise identification of root-knot nematode species establishes a critical foundation for the subsequent implementation of targeted control measures.

Fusarium head blight (FHB), caused by the major plant pathogen Fusarium graminearum, is a globally destructive disease that severely threatens the production and quality of wheat and other cereal crops. Calcineurin is a crucial serine/threonine protein phosphatase in the calcium signal pathway, yet its function in plant pathogenic fungi remains unclear. In this study, a homolog of the calcineurin regulatory subunit, designated FgCnb1, was identified in F. graminearum. The FgCNB1 gene knockout mutant (ΔFgcnb1) was generated, and the corresponding complemented strain (ΔFgcnb1-C) was obtained. Subcellular localization revealed that FgCnb1 is localized to the cytoplasm and accumulates at the septal pores of both hyphae and conidia. Phenotypic analyses showed that, compared with the wild-type PH-1 and complemented strains, the ΔFgcnb1 mutant exhibited a significantly reduced hyphal growth rate and a near-complete loss of hyphal expansion ability. Furthermore, the mutant failed to produce perithecia and conidia, indicating abolished sexual and asexual reproduction. Pathogenicity assays on wheat spikes confirmed that the ΔFgcnb1 mutant was completely non-pathogenic. In conclusion, FgCnb1 is a key regulator of multiple biological processes in F. graminearum, including vegetative growth, conidiation, sexual reproduction, and pathogenicity. This study not only identifies FgCnb1 as a potential target for novel fungicide development but also provides a valuable reference for understanding calcineurin functions in other pathogenic fungi.

Pokkah boeng disease (PBD), primarily caused by Fusarium sacchari, leads to severe reductions in sugarcane yield and sugar content. The 14-3-3 proteins are evolutionarily conserved acidic regulators in eukaryotes, typically functioning as homodimers or heterodimers. F. sacchari possesses two 14-3-3 protein-encoding genes, FsBmh1 and FsBmh2. Their protein products, FsBmh1 and FsBmh2, coordinately yet differentially regulate fungal growth, development, and virulence. Sequence alignment revealed that the most significant divergence between FsBmh1 and FsBmh2 lies within a 35-amino acid (aa) region at their C-termini, suggesting this region may be critical for their functional differentiation. To investigate whether this divergent region underlies their functional differences, we constructed the corresponding complemented strains with deletions of this 35-aa C-terminal region: ΔFsBmh1/FsBmh1^ΔC35 and ΔFsBmh2/FsBmh2^ΔC35. Using the single-gene deletion mutants (ΔFsBmh1, ΔFsBmh2) and the corresponding full-length complemented strains (ΔFsBmh1/FsBmh1, ΔFsBmh2/FsBmh2) as controls, we systematically evaluated the impact of the C-terminal region on fungal growth, development, and virulence. The results demonstrated that: 1) The conidial production of ΔFsBmh1/FsBmh1^ΔC35 was restored to wild-type levels, but its virulence was not fully recovered, indicating that the C-terminal sequence of FsBmh1 is crucial for the full virulence of the fungus. Furthermore, similar to ΔFsBmh1, this mutant produced elongated conidia, demonstrating that the C-terminus of FsBmh1 specifically determines conidial morphology. 2) ΔFsBmh2/FsBmh2^ΔC35 showed no significant differences (P<0.05) from ΔFsBmh2 in conidiation, conidial morphology and germination, hyphal development, and virulence, confirming that all phenotypic defects observed in ΔFsBmh2 stem from the absence of its C-terminus. In conclusion, the C-terminal 35 aa of the 14-3-3 proteins are crucial for maintaining their normal biological functions and represent the key region determining the functional differentiation between FsBmh1 and FsBmh2.

Rice sheath blight, caused by Rhizoctonia solani, is one of the three major diseases of rice, posing a serious threat to grain yield. The lack of highly resistant rice varieties makes the control of this disease a significant challenge. Previous studies have shown that the pathogen hijacks rice sugar transporter proteins (SWEETs) to acquire host sugars, thereby enhancing its virulence. Conversely, the accumulation of sugars within plant cells can activate sugar signaling pathways and strengthen resistance against pathogens. However, whether sugar signaling regulates rice resistance to sheath blight remains unclear. In this study, inoculation with R. solani induced starch synthesis in rice leaves and increased apoplastic levels of glucose, fructose, and sucrose. To further investigate the role of sugars in sheath blight resistance, we performed a comparative transcriptome analysis in rice plants following R. solani infection. The results revealed distinct expression trends of genes related to sugar transport, synthesis, and signaling in leaves of the moderately resistant rice variety Teqing and the susceptible variety Lemont. At 12 hours post-inoculation, Teqing leaves accumulated more starch than those of Lemont, and their apoplastic glucose, fructose, and sucrose contents were also significantly higher. Based on the transcriptome data, reverse transcription-quantitative real-time PCR (RT-qPCR) was used to validate the expression patterns of selected genes. The sugar signaling kinase genes HXK1 and SAPK9 were chosen for further functional analysis through the generation of overexpression and geneknockout mutants. Resistance evaluation demonstrated that overexpression of HXK1 or SAPK9 significantly enhanced rice resistance to sheath blight compared with the wild type, whereas the corresponding knockout mutants exhibited increased susceptibility. Taken together, these results indicate that HXK1 and SAPK9 positively regulate rice resistance to sheath blight. This study provides an important theoretical basis for breeding rice varieties resistant to sheath blight and developing novel plant immunity activators.

Oidium heveae, the rubber tree powdery mildew fungus, activates EDS1 (enhanced disease susceptibility 1)-mediated defense signaling in Arabidopsis thaliana. The TNL-class resistance protein WRR4B (white rust resistance 4B) mediates broad-spectrum resistance to powdery mildew by positively regulating the expression of EDS1 signaling pathway-related genes. The N-hydroxy-pipecolic acid (NHP) biosynthesis pathway functions downstream of EDS1 and forms a positive feedback regulation with EDS1. To investigate whether the NHP pathway is involved in Arabidopsis resistance to O. heveae and its relationship with WRR4B, this study employed quantitative real-time PCR to examine the expression of genes encoding key enzymes in the NHP biosynthesis pathway, including ALD1 (AGD2-like defense response protein 1), SARD4 (SAR-deficient 4), and FMO1 (flavin-dependent monooxygenase 1). Additionally, we analyzed hyphal growth, cell death, and reactive oxygen species accumulation in wild-type Col-0, fmo1, and wrr4b mutant plants inoculated with O. heveae. The results showed that WRR4B positively regulates the expression of ALD1, SARD4, and FMO1 upon O. heveae infection. Compared with the wild type, both fmo1 and wrr4b mutants displayed similar early susceptible phenotypes and later resistant responses to O. heveae, suggesting that WRR4B may function in resistance through the NHP signaling pathway. Furthermore, O. heveae failed to produce conidia in the salicylic acid (SA) mutant sid2 (SA induction-deficient 2), with only weak cell death observed, whereas in the fmo1 mutant, abundant conidia were produced and severe cell death was triggered. This difference implies that SA- and NHP/FMO1-mediated resistance signaling pathways against O. heveae in Arabidopsis are distinct. Comparative genomic analysis revealed that the rubber tree (Hevea brasiliensis) harbors conserved HbEDS1 and HbFMO1 orthologs, suggesting that rubber trees possess an immune regulatory network similar to that of Arabidopsis. These findings provide a theoretical basis for the development of WRR4B-transgenic rubber trees with enhanced resistance to powdery mildew disease.

This study presents the first integrated genomic and transcriptomic analysis of the Ralstonia pathogen responsible for bacterial wilt in eucalyptus in China, aiming to elucidate its taxonomic status, genomic characteristics, and adaptive strategies for xylem colonization. Based on 16S rRNA phylogeny and comparative genomics, the isolates were identified as a potential new subspecies of Ralstonia pseudosolanacearum. Compared with the type strain R. pseudosolanacearum LMG 9637^T, the isolates possess significantly more genes encoding glycosyl transferases, glycoside hydrolases, type III secretion system effectors, and pathogenicity-related factors, indicative of enhanced cell wall-degrading capacity and a more complex virulence regulatory network. By combining pathogen dynamics monitoring with transcriptomic profiling across different infection stages, we revealed the proliferation pattern of the pathogen in xylem and found that the hypoxic and nutrient-limited xylem environment suppressed central metabolic pathways such as oxidative phosphorylation and carbon metabolism, while activating virulence-associated pathways, including the secretion system, chemotaxis, and flagellar assembly. Concurrently, nitrogen, sulfur, and methionine metabolic pathways were markedly upregulated, providing essential biosynthetic precursors and metabolic energy to support pathogen proliferation and virulence expression. This coordinated regulatory mechanism plays a critical role in pathogenicity. Collectively, this study characterizes the genomic profile of the eucalyptus bacterial wilt pathogen, reveals its adaptive mechanisms and key metabolic pathways during xylem colonization, and suggests potential targets for future disease management.

Most studies on plant disease image recognition are based on the images of individual diseases, and there are few related studies based on the images of mixed diseases acquired under the complex field environments. In this study, a total of 16 562 images of three wheat leaf diseases (stripe rust caused by Puccinia striiformis f. sp. tritici, leaf rust caused by P. triticina, and powdery mildew caused by Blumeria graminis f. sp. tritici) with single background and complex background were acquired during different wheat growth stages under both field and indoor environments, including the images of individual diseases and mixed diseases. According to the distribution of the labeled disease instances, a class-balanced mixed image dataset was constructed, then it was divided into a single-background image dataset and a complex-background image dataset, and subsequently, each of the three image datasets was divided into training set, validation set, and testing set based on the disease instance quantity ratio of 7∶2∶1, respectively. Nine object detection models, including YOLOv5n, YOLOv6n, YOLOv8n, YOLOv9t, YOLOv10n, YOLO11n, YOLO12n, SSD, and Faster R-CNN, were used to carry out wheat leaf disease detection based on the three image datasets, including the mixed image dataset, the single-background image dataset, and the complex-background image dataset. The results showed that on each image dataset, the comprehensive performance of each YOLO model was markedly better than the SSD and Faster R-CNN models, except that of YOLOv6n on the single-background image dataset. YOLO11n, YOLOv10n, and YOLOv8n had the best comprehensive performance on the mixed image dataset, the single-background image dataset, and the complex-background image dataset, respectively. By comprehensively considering the characteristics of the three constructed image datasets and the detection results, the mixed image dataset was regarded as the most suitable image dataset for building the image-based wheat leaf disease detection model. Furthermore, among all the target detection models, YOLO11n performed best on the testing set of the mixed image dataset, with the Precision, Recall, F1 score, mAP₅₀, and mAP_50-95 of 76.95%, 72.59%, 74.70%, 76.08%, and 54.19%, respectively. Meanwhile, YOLO11n demonstrated advantages in wheat leaf disease detection on both the single-background and complex-background image datasets. On the whole, the YOLO11n model was the optimal for wheat leaf disease detection among the nine selected target detection models. In this study, a method for the detection of multi-lesion images and mixed images of wheat leaf diseases and supports for plant disease detection in complex scenarios were provided.

To investigate the role of volatile organic compounds (VOCs) from Lindera megaphylla leaves in modulating chrysanthemum resistance against Pseudomonas syringae infection, VOCs released from crushed leaves were applied to both the pathogen and chrysanthemum cuttings. By combining results from plate inhibition assays, in vivo inoculation, and gene expression analysis, we systematically evaluated the effect of L. megaphylla VOCs on chrysanthemum disease resistance. The results showed that L. megaphylla VOCs directly inhibited the growth of P. syringae. Chrysanthemum plants pretreated with VOCs exhibited significantly reduced disease symptoms, alleviated damage to the photosynthetic system, and decreased callose deposition, reactive oxygen species accumulation, and bacterial load per unit leaf area. The key active component, E-2-Hexenal (E-2-HAL), demonstrated a dual role: disrupting bacterial cell membranes and activating plant defense signaling. Quantitative realtime PCR (qPCR) further revealed that L. megaphylla leaf VOCs modulated the expression of key genes involved in JA biosynthesis and signaling (CmMYC2, CmERF109, and CmCOI1) in chrysanthemum, promoting endogenous JA accumulation and consequently enhancing disease resistance. This study reveals a synergistic mechanism by which L. megaphylla leaf VOCs enhance chrysanthemum resistance through “direct antibacterial activity” and “JA-dependent induced resistance”, providing a theoretical basis for developing VOC-based green control strategies.

In recent years, tobacco root rot has become a widespread and damaging disease across major tobacco-growing regions nationwide, causing significant economic losses in tobacco production. Tobacco root rot is a typical soil-borne disease, which is closely linked to soil conditions and microbial communities. This study classified tobacco fields in Yuxi City, Yunnan Province, into four categories based on disease severity: healthy, low incidence, moderate incidence, and high incidence. Rhizosphere soil samples were collected from both healthy and diseased tobacco plants within each category. Illumina MiSeq high-throughput sequencing technology was employed to analyze bacterial and fungal community structure characteristics in rhizosphere soils of healthy and diseased tobacco plants across the four categories. Results indicated that bacterial diversity was highest in rhizosphere soils of moderately diseased plants, while fungal diversity was highest in rhizosphere soils of mildly diseased plants. However, the severity of tobacco root rot was not correlated with Fusarium biomass in the soil. Furthermore, 100 antagonistic bacterial strains were isolated from the rhizosphere soils of mildly and severely diseased tobacco root rot plants, predominantly belonging to the genus Bacillus. Interestingly, Bacillus aerius was specifically isolated from the rhizosphere soil of mildly diseased plants. In vitro assay revealed that Bacillus aerius CB74 exhibited particularly potent inhibitory effects. Further indoor and field trials confirmed the significant efficacy of CB74 in controlling Fusarium. This study analyzed bacterial and fungal community structures in the rhizosphere soil of diseased tobacco plants, providing theoretical foundations and potential microbial biocontrol resources for the ecological management of soil-borne diseases.

Bacterial leaf streak, bacterial leaf blight, bacterial grain and seedling rot are the three major quarantine diseases of rice, causing severe yield losses during epidemics. Strict seed quarantine is one of the most effective ways to prevent the long-distance spread of pathogens across regions. Here, we employed a portable device (P1000F) based on microfluidic technology and real-time quantitative PCR (qPCR) for multiplex detection of rice diseases. The P1000F integrates nucleic acid extraction and purification, multi-target rapid amplification and automated result visualization into a single platform. The assay requires only minimal sample preparation, and after 36 minutes the result is automatically generated and interpreted by the instrument. The limit of detection (LOD) of bacteria suspensions and DNA were 4.02×10³ CFU·mL^-1 and 1.44×10^-3 ng·μL^-1 for bacterial leaf streak, 5.09×10² CFU·mL^-1 and 3.13×10^-2 ng·μL^-1 for bacterial leaf blight, 1.94×10² CFU·mL^-1 and 5.67×10^-3 ng·μL^-1 for bacterial grain and seedling rot, respectively. This method is conducive to enhance the capacity for rapid on-site detection of plant pathogens.

Plant quarantine pathogens carried in imported and exported agricultural products have long been a critical issue in international trade, as they directly impact the agricultural and forestry products and ecological security of many countries. This study developed a TaqMan-based microfluidic chip capable of simultaneously detecting common quarantine pathogens in unprocessed grains with 100% specificity. The detection limit was 1 copy·μL^-1 for 3 pathogens (including Cadophora gregata, southern bean mosaic virus (SBMV), and tomato ringspot virus (ToRSV)) and 10 copies·μL^-1 for the remaining 15 pathogens (including Diaporthe aspalathi,Fusarium tucumaniae,arabis mosaic virus (ArMV), Phytophthora sojae, Diaporthe caulivora, Fusarium virguliforme, bean pod mottle virus (BPMV), Tilletia indica, Tilletia walkeri, wheat streak mosaic virus (WSMV), Pantoea stewartii subsp. stewartii, Clavibacter michiganensis subsp. nebraskensis, maize chlorotic mottle virus (MCMV), Plenodomus lingam, and Clavibacter michiganensis subsp. michiganensis). The microfluidic chip was successfully applied to detect pathogens in imported soybean-related samples, including Diaporthe caulivora, bean pod mottle virus (BPMV), and southern bean mosaic virus (SBMV). The detection results were accurate, with no false positives or negatives. Therefore, microfluidic chips hold significant promise for application in port plant quarantine.

Tomato leaf curl New Delhi virus (ToLCNDV) is an emerging Begomovirus that causes severe da-mage to cucurbit crops in China. In this study, we developed a visual loop-mediated isothermal amplification (LAMP) assay to rapidly detect ToLCNDV. The sensitivity and specificity of the assay were improved through primer screening and optimization of reaction conditions. The assay is simple, rapid, and can be completed within 15 minutes at 65 ℃. A clear color change in the reaction solution can visually determine detection results. It exhibits high sensitivity, with a detection limit of 3.07×10² copies·μL^-1 for ToLCNDV. It also demonstrates high specificity, showing no cross-reactivity with other common begomoviruses or RNA viruses. Furthermore, DNA extracted using a sucrose-based crude extraction method was tested to be suitable for this LAMP system, which greatly enhances detection efficiency. Collectively, these features make it a practical and effective tool for on-site detection of ToLCNDV in the field.

Viral diseases of shallot are widespread and cause serious damage. Common viruses include shallot latent virus (SLV), onion yellow dwarf virus (OYDV), shallot yellow stripe virus (SYSV) and shallot virus X (SVX), which often cause severe degeneration of shallot germplasm by multiple infections. The establishment of a sensitive and efficient detection method is fundamental to controlling viral diseases and screening virus-free bulbs. In this study, a multiplex reverse transcription-polymerase chain reaction (RT-PCR) detection method for the four viruses SLV, OYDV, SYSV and SVX was established. The amplified target DNA fragments of the four viruses were 917, 656, 510 and 289 bp. The optimal annealing temperature for the reaction was 58 ℃. The concentrations of each viral primer were 0.4, 0.1, 0.4 and 0.6 μmol·L^-1. The minimum detection limits of this method for the four viruses were 1, 10^-1, 10^-4 and 10^-4 ng·μL^-1, respectively. This method can accurately and efficiently detect the virus carrying status of shallot plants.

Maize yellow mosaic virus (MaYMV), a novel virus first discovered and reported in China in 2016, belongs to the genus Polerovirus. It has been detected in maize, cereal crops, and weeds in Asia, Africa, and America. However, artificial field aphid transmission system of MaYMV had not been previously reported. In this study, an aphid transmission system for MaYMV was established through aphid feeding, virus transmission, and verified using reverse transcription-PCR detection and symptom observation. Our results showed that after feeding on MaYMV-infected plants, both Schizaphis graminum and Rhopalosiphum maidis were able to acquire the virus, with higher virus loads detected in Rhopalosiphum maidis than in Schizaphis graminum. When 5 aphids were used for transmission, the efficiency of MaYMV transmission was higher in maize. When transmission was tested during the first leaf fully expanded (V1) stage, the efficiency of MaYMV transmission was also higher in maize. MaYMV could infect maize after 1 day of aphid transmission, and was detectable in maize leaves on the 7th day after transmission with the viral titers gradually increasing over time. Subsequently, pot and field transmission experiments were conducted using the established aphid transmission system for MaYMV. The results indicated that MaYMV infection induced symptoms such as dwarfing and stunting in maize. Notably, the MaYMV-susceptible inbred line ‘Zhu3151’ developed leaf reddening symptoms. The establishment of aphid transmission system provides crucial technical support for future research and control of MaYMV.

To clarify the symptom diversity and the causal pathogen of maize white spot in Liaoning Province, typical symptomatic leaves were collected from multiple regions in 2025 for systematic observation of symptoms, and isolation and identification of the pathogen. Field symptoms were classified into five types: white spot, brown spot, stripe spot, blighted spot, and cloudy spot. The dominant fungal isolates obtained from each symptom type through tissue isolation shared identical morphological characteristics, consistent with Setophoma zeae-maydis. Five representative isolates, one from each symptom type, were selected for pathogenicity tests. All five isolates induced the same typical white spot symptoms on maize leaves, rather than reproducing the five distinct field symptom types. Molecular identification based on ITS and LSU sequences confirmed that all five isolates shared 100% sequence identity with S. zeae-maydis. These findings elucidate the symptom-pathogen relationship of maize white spot in Liaoning Province and provide a basis for field diagnosis and disease management.

To identify the causal agent of a blueberry fruit disease characterized by shrunken and withered fruits with orange-red conidial masses in Hezhang County, Guizhou Province, fungal isolates were obtained from symptomatic fruits using tissue isolation method. Representative isolates were identified based on morphological characteristics and a multi-locus phylogenetic analysis (ITS, glyceraldehyde-3-phosphate dehydrogenase, chitin synthase, actin, and β-tubulin). Pathogenicity was confirmed through in vitro fruit inoculation assays. The results showed that the isolates induced typical anthracnose symptoms on healthy blueberry fruits, and the same fungus was re-isolated from the lesions, fulfilling Koch's postulates. Phylogenetic analysis indicated that the two representative isolates (JZB330473, JZB330474) clustered within Colletotrichum godetiae with 100% maximum likelihood bootstrap support. Combined with morphological characteristics, they were identified as C. godetiae. This is the first report of C. godetiae causing blueberry fruit anthracnose in China. Our findings provide a scientific basis for the diagnosis and targeted control of blueberry anthracnose in Guizhou Province and enrich the known species diversity of Colletotrichum associated with blueberry anthracnose in China.

Leaves showing symptoms of tobacco white leaf spot were collected from the tobacco field of ‘Yunyan 97’ in Ankang City, Shaanxi Province, China. Forty-three strains were isolated by the tissue isolation method. Twenty-seven strains showed morphological characteristics similar to the representative isolate BXAK1, accounting for 62.8%, and their pathogenicity was verified by Koch's postulates. Strain BXAK1 produced pycnidia and cleistothecia under UV-induced culture on OA plates containing sterilized tobacco stalks, and the morphology of conidia or ascospores was consistent. There was no color change on OA medium by the NaOH spot test. The strain cultured on PDA medium was greatly influenced by light conditions and continuous light was the most suitable for its growth. According to the analysis of the phylogenetic tree constructed by ACT gene sequence, strain BXAK1 and Stagonosporopsis inoxydabiliscbs CBS 425.90 were clustered into one branch. Based on the above results, the pathogen causing tobacco Stagonosporopsis leaf spot was identified as S. inoxydabilis. The new pathogen of tobacco Stagonosporopsis leaf spot disease was clarified, which provided theoretical basis for the occurrence, epidemic and comprehensive control of the disease.

In 2025, a previously unreported bacterial leaf spot disease was observed on soybean (Glycine max) during the middle and late growth stages in the northern spring soybean-growing region of China. Disease incidence exceeded 80% in severely affected fields, resulting in considerable economic losses. Bacterial strains were isolated from symptomatic leaves, and pathogenicity was confirmed by Koch’s postulates. The pathogen was identified as Pseudomonas amygdali pv. tabaci by phylogenetic analyses based on 16S rDNA gene, gyrB, rpoB, and rpoD sequences. To our knowledge, this is the first report of soybean wildfire caused by P. amygdali pv. tabaci in China. These findings provide a basis for future studies and management of this disease.