Plant disease最新文献

{"title":"Brefeldin A, an effector of <i>Ascochyta medicaginicola</i>, mediates virulence.","authors":"Xunfeng Chen, Yanxiu Pan, Yanru Lan, Zhibiao Nan, Peng Gao, Qiuyan Song","doi":"10.1094/PDIS-06-26-1240-RE","DOIUrl":"https://doi.org/10.1094/PDIS-06-26-1240-RE","url":null,"abstract":"<p><p>Alfalfa spring black stem, caused by Ascochyta medicaginicola, severely affects global alfalfa production. This study isolates and identifies brefeldin A (BFA) from pathogen fermentation products and demonstrates its strong phytotoxicity. BFA inhibits leaf photosynthesis and seed germination in a dose-dependent manner at concentrations ≥10-4 mol. Significant variation in BFA sensitivity is observed among cultivars, with 'Longdong' showing the highest susceptibility and 'Spyder' displaying relative resistance. LC-MS/MS analysis detects BFA in naturally infected plants, confirming its presence during disease development. BFA treatment increases leaf relative electrolyte leakage, reduces chlorophyll content, and induces chloroplast structural damage, including shrinkage and disintegration of grana lamellae. Furthermore, BFA enhances defense-related enzyme activities and alters the expression of 953 genes. Gene set enrichment analysis reveals that photosynthesis pathways are significantly down-regulated, whereas defense responses are up-regulated. These results identify BFA as a key virulence effector and provide a basis for disease-resistant breeding and ecological management of spring black stem disease.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148983069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whole-genome characterization and phylogenetic placement of <i>Fusarium oxysporum</i> f. sp. <i>vasinfectum</i> isolates.","authors":"Catherine Danmaigona Godsent-Ogbe, Eun-Gyu No, Lin Zhang, Terry Wheeler, Jane K Dever, Ping He, Libo Shan","doi":"10.1094/PDIS-11-25-2248-RE","DOIUrl":"https://doi.org/10.1094/PDIS-11-25-2248-RE","url":null,"abstract":"<p><p>Fusarium wilt of cotton, caused by Fusarium oxysporum f. sp. vasinfectum (<i>Fov</i>), remains a persistent threat to cotton production worldwide. Among the known races, <i>Fov</i> race 4 and its extra-virulent variants cause particularly severe losses in Upland cotton. Although several Fov genome assemblies have been assigned to races, the genomic diversity and evolutionary relationships among pathogenic and non-pathogenic isolates associated with cotton outbreaks remain poorly understood at the whole-genome level. This study addressed these gaps by generating and comparing high-quality genome assemblies of four Fusarium isolates collected from Texas cotton fields: two pathogenic (TX17-24 and TX18-9) and two non-pathogenic (TX17-6 and TX18-6). Draft assemblies were generated using Oxford Nanopore long reads and polished with Illumina reads. Comparative genomic analyses showed that pathogenic isolates possessed larger genomes and more conserved orthologous families, whereas non-pathogenic isolates contained more unique genes. Analyses of predicted secreted effectors, transposable elements, and carbohydrate-active enzymes further distinguished pathogenic and non-pathogenic lineages, suggesting roles in virulence adaptation and genome plasticity. Phylogenomic analyses using k-mer-based, assembly- and alignment-free methods incorporated all available long-read <i>Fov</i> genomes and revealed substantial genetic diversity within races 1 and 4, clustering isolates into multiple sublineages. These findings show that <i>Fov</i> race diversification is underestimated when based on traditional classification schemes and may be shaped by host specialization, geographic separation, or horizontal gene transfer. This work advances our understanding of the genomic diversity and evolutionary dynamics of <i>Fov</i> and establishes a foundation for improved race identification and characterization of Fusarium wilt pathogenesis in cotton.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148983217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Symptomatology and Host Range of <i>Clavibacter</i> Species Associated with Small Grain Cereals.","authors":"Nastaran Zamani, Asma Rahmanzadeh, Anne Vidaver, Ebrahim Osdaghi","doi":"10.1094/PDIS-05-26-0881-RE","DOIUrl":"https://doi.org/10.1094/PDIS-05-26-0881-RE","url":null,"abstract":"<p><p>Bacterial mosaic of small grain cereals is caused by five Clavibacter species, i.e., Clavibacter davisi, Clavibacter rahimiani, Clavibacter tessellarius, Clavibacter vidaverae, and Clavibacter zhangzhiyongii. While taxonomic range of the causal agents has only recently been investigated, biological features and host range of the pathogens remain unexplored. In this study, phenotypic features, symptomatology, and host range of the five Clavibacter species were evaluated. The host range assays were performed on seven small grain cereals' species, i.e., barley, maize, millet, oat, sorghum, triticale, and wheat under controlled greenhouse conditions. The five Clavibacter species showed considerable differences in colony color and morphology on agar-based culture media. The range of field symptoms induced by Clavibacter species under field conditions expands beyond mosaic patterns and yellowing, including necrotic lesions and leaf desiccation. Whereas water-soaking and oozing were not observed in the bacterial mosaic infections. Under greenhouse conditions, symptoms were similar to those recorded in the field. Clavibacter tessellarius strains were the most aggressive agents with the widest host range, infecting all evaluated plant species except maize. Clavibacter rahimiani and Clavibacter zhangzhiyongii strains induced noticeable symptoms only on sorghum and oat plants, while Clavibacter vidaverae and Clavibacter davisi did not induce any symptoms on oat and millet. Sorghum plants became infected with all strains of the five Clavibacter species, while only Clavibacter tessellarius strains infected millet plants. These findings provided novel insight into the biology of bacterial mosaic pathogens and highlighted the importance of precise symptomatology of the disease in the field surveys and quarantine inspections.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148983304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antagonistic microorganisms against Verticillium wilt in yellow-fleshed kiwifruit and their effect on Bruno rootstock physiology.","authors":"Daniel Ardiles-González, Arturo Calderon-Orellana, Juan G San Martín, Braulio E Ruiz, Inés Eradia Figueroa, Hector Garcia, Ernesto Antonio Moya-Elizondo","doi":"10.1094/PDIS-04-26-0706-RE","DOIUrl":"https://doi.org/10.1094/PDIS-04-26-0706-RE","url":null,"abstract":"<p><p>Verticillium wilt, caused by <i>Verticillium nonalfalfae</i> MLST2, is an emerging disease affecting yellow-fleshed kiwifruit in Chile, and effective management strategies are currently unavailable. This study evaluated the biocontrol potential of antagonistic microorganisms against <i>V. nonalfalfae</i> MLST2, their interaction with different kiwifruit rootstocks, and their effects on plant physiological performance. Six <i>Pseudomonas protegens</i> and six <i>Bacillus velezensis</i> isolates were screened <i>in vitro</i>, and the most effective strains were subsequently evaluated with Trichoderma harzianum RGM3510 under controlled conditions. <i>B. velezensis</i> BcB1 and <i>P. protegens</i> C025 showed the highest in vitro inhibition of mycelial growth (46.2 and 40.2%, respectively). However, disease suppression in planta depended strongly on the rootstock genotype. Among the evaluated rootstocks, Z5Z6 consistently exhibited the lowest wilt severity, whereas <i>P. protegens</i> C025 significantly reduced disease development compared with the inoculated control. In contrast, <i>B. velezensis</i> BcB1 failed to suppress disease and, in some rootstocks, increased wilt severity. Although cumulative disease severity in Bruno plants was not significantly reduced by the biological treatments, <i>P. protegens</i> C025 produced disease levels comparable to the non-inoculated control. Moreover, treatments containing <i>P. protegens</i> improved stomatal conductance and photochemical reflectance index, indicating lower physiological stress associated with pathogen infection. These results demonstrate that the success of biological control against <i>V. nonalfalfae</i> MLST2 is determined by the interaction between antagonistic microorganisms and rootstock genotype, highlighting <i>P. protegens</i> C025 in combination with the Z5Z6 rootstock as a promising strategy for the integrated management of Verticillium wilt in kiwifruit.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148983054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-throughput qPCR phenotyping of Verticillium stripe resistance in <i>Brassica napus</i> under natural field infection.","authors":"Mohamed Samir Youssef, Sean Walkowiak, Christian Obermeier, Isobel A P Parkin, Sally Lynne Vail, Robert W Duncan, Harmeet Singh Chawla","doi":"10.1094/PDIS-06-26-1149-RE","DOIUrl":"https://doi.org/10.1094/PDIS-06-26-1149-RE","url":null,"abstract":"<p><p>Verticillium stripe, caused by Verticillium longisporum, is an emerging threat to Brassica napus production in North America, with increasing field incidence and yield loss reported in affected regions. Although visual ratings are useful for rapid field assessment, resistance breeding is constrained by the lack of scalable, objective phenotyping methods that can quantify pathogen colonization across large genotype panels under field conditions. Here, we adapted and validated an established OLG70/OLG71-based SYBR Green qPCR assay within a high-throughput workflow combining freeze-dried hypocotyl sampling and magnetic bead-based DNA extraction to quantify V. longisporum DNA in field-grown B. napus. A panel of 215 B. napus genotypes was evaluated at two naturally infested field sites in Manitoba, Canada. The assay produced robust standard curves across plates, with R² values >0.99, amplification efficiencies of 95-105%, and low intra-plate variability, supporting reliable quantification over a broad dynamic range. Log₁₀-transformed fungal DNA quantities showed strong cross-environment consistency, with genotype rankings largely conserved between sites (Spearman ρ = 0.82). At the Glenlea site, qPCR-derived fungal load was strongly associated with visual Verticillium stripe severity (Spearman ρ = 0.68; R² ≈ 0.44; Kruskal-Wallis P = 1.59 × 10⁻¹⁷), indicating that hypocotyl colonization measured by qPCR captures biologically meaningful variation in disease expression. This scalable qPCR-based platform provides a repeatable, high-resolution phenotype for large-scale germplasm screening and future genetic analyses aimed at improving Verticillium stripe resistance in canola.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148930893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal changes in the population structure of the pathogen <i>Globisporangium irregulare</i> in a hydroponic Eustoma production system in Japan.","authors":"Ayaka Hieno, Kazuma Morita, Kayoko Otsubo, Wenzhuo Feng, Haruhisa Suga, Koji Kageyama","doi":"10.1094/PDIS-03-26-0634-RE","DOIUrl":"https://doi.org/10.1094/PDIS-03-26-0634-RE","url":null,"abstract":"<p><p>Temporal changes in the population structure of <i>Globisporangium irregulare</i> were investigated over three years (2015-2017) in a hydroponic Eustoma production system in Fukushima, Japan. The aims of this study were to determine the phylogenetic affiliation of Fukushima isolates, their potential as a source of contamination, and whether any specific molecular types were associated with pathogenic traits. Phylogenetic analyses based on genetic distances revealed that isolates exhibiting an intermediate RAPD DNA group I/II genotype occupied phylogenetic positions between groups I and II, suggesting recombination across lineages. The 2015 population exhibited relatively high genetic diversity, whereas isolates in 2016-2017 were genetically more uniform and often shared identical genotypes across cultivation cycles. These results indicate that pathogen populations were likely maintained within the hydroponic system, probably via infected plant residues, rather than repeatedly being introduced from the surrounding environment. No clear association was detected between molecular type and pathogenicity-related characteristics. Extracellular enzyme activity analysis revealed increased cellulase and xylanase activities with time while a reverse trend was seen in pectinase activity. However, these year-related trends did not correlate with disease severity. Isolates dominant after 2015 showed lower heat tolerance and reduced zoospore productivity compared with the 2015 population. The observed genotype replacement therefore appears to reflect selection for persistence within the hydroponic environment rather than increased virulence, stress tolerance, or dispersal ability. These results suggest that disease management in hydroponic Eustoma production should consider the potential for long-term survival within cultivation facilities and emphasize the importance of sanitation and residue management.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148930817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated Clay-Azoxystrobin and <i>Trichoderma</i>-Based Treatments for Managing <i>Magnaporthiopsis maydis</i> Maize Late Wilt Disease.","authors":"Elhanan Dimant, Peleg Hadari, Ofir Degani","doi":"10.1094/PDIS-03-26-0587-RE","DOIUrl":"https://doi.org/10.1094/PDIS-03-26-0587-RE","url":null,"abstract":"<p><p><i>Magnaporthiopsis maydis</i>, the causal agent of maize late wilt disease (LWD), is a destructive soil-borne pathogen for which effective and sustainable control remains challenging. We evaluated an integrated management strategy combining clay-based azoxystrobin formulations with <i>Trichoderma</i>-based seed coating in two maize hybrids differing in susceptibility to LWD: the highly susceptible sweet maize hybrid Prelude and the moderately susceptible fodder hybrid Colossus. Bentonite- and sepiolite-based azoxystrobin formulations were applied alone or with two <i>Trichoderma</i> mixtures under net-house conditions. Based on an in vitro assay, <i>T. asperellum</i>, <i>T. longibrachiatum</i>, and <i>T. virens</i>, which inhibited pathogen growth by 37 to 53%, were selected and combined. At the latent mid-season stage, treatment effects on plant growth were limited, but qPCR showed that pathogen DNA levels in infected, untreated Prelude plants were up to 24-fold higher than in Colossus. In Prelude, several treatments reduced pathogen DNA to 2-9% of the infected control. By the end of the season, treatment efficacy became more pronounced. In Colossus, bentonite-azoxystrobin alone or combined with <i>Trichoderma</i>-based seed coating performed best, increasing shoot weight by 62 to 67%, cob weight by 85 to 90%, and health indices by 52 to 67% relative to the infected control. In Prelude, <i>Trichoderma</i>-based seed coating combined with sepiolite-azoxystrobin produced the strongest response, increasing shoot and cob weight by 116 and 145%, respectively. Across both cultivars, clay-based formulations, alone or combined with biological treatment, reduced pathogen DNA to near zero. These findings support this integrated approach for LWD management under net-house conditions, pending field validation.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148930809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Fusarium oxysporum</i> f. sp. <i>crypti</i>, a novel forma specialis causing Fusarium wilt of mitsuba, <i>Cryptotaenia japonica</i>.","authors":"Hiroki Saito, Koji Tobata, Yukiko Kato, Shunsuke Kotera, Shuta Asai, Chiyusa Ishihara, Shunsuke Miyashima, Atsushi Takeda, Yasuaki Morita, B Gillian Turgeon, Antonio Di Pietro, Ken Komatsu, Tsutomu Arie","doi":"10.1094/PDIS-06-26-1146-RE","DOIUrl":"https://doi.org/10.1094/PDIS-06-26-1146-RE","url":null,"abstract":"<p><p><i>Fusarium oxysporum</i> isolates causing Fusarium wilt in mitsuba (<i>Cryptotaenia japonica</i> Hassk.; also referred to as Japanese honeywort, Japanese honewort, or Japanese parsley) have traditionally been classified as f. sp. <i>apii</i>. However, some reports have indicated that the host-pathogenic <i>F. oxysporum</i> isolates derived from mitsuba are nonpathogenic to celery, the principal host of f. sp. <i>apii</i>. In this study, we aimed to elucidate the differences among isolates from mitsuba, coriander, and celery in terms of host range, phylogenetic relationships, genomic synteny, and effector profiles. Inoculation assays revealed a clear distinction in host range between the mitsuba, coriander, and celery isolates. Phylogenetic analyses based on the rDNA intergenic spacer and translation elongation factor sequences indicated a distant relationship between mitsuba isolates and those from coriander and celery. Whole-genome analysis based on high-quality de novo-assembled genomes, including telomere-to-telomere-level assemblies of isolates from mitsuba, coriander, and celery, showed that the mitsuba isolates possess conserved accessory chromosomal regions absent in celery and coriander isolates. Moreover, effector profiling identified a specific pattern of effector repertoires shared by the mitsuba isolates. These findings suggest that the host-pathogenic <i>F. oxysporum</i> isolates derived from mitsuba represent a forma specialis distinct from f. sp. <i>apii</i>. Thus, we propose designating the <i>F. oxysporum</i> isolates from mitsuba that cause Fusarium wilt as <i>Fusarium oxysporum</i> f. sp. <i>crypti forma specialis nova</i>.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148930819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of fermentation conditions for <i>Trichoderma hamatum</i> T2 and its efficacy against larch shoot blight caused by <i>Neofusicoccum laricinum</i>.","authors":"Fanghong Liu, Xiaoshuang Song, Yingying Qian, Banghao Wang, Wenfeng Cui, Boru Zhou, Xun Deng","doi":"10.1094/PDIS-05-26-0925-RE","DOIUrl":"https://doi.org/10.1094/PDIS-05-26-0925-RE","url":null,"abstract":"<p><p>Trichoderma hamatum T2 is an antagonistic fungus with biocontrol potential. In this study, single-factor experiments combined with response surface methodology were employed to optimize liquid fermentation conditions for T2, in order to enhance its inhibitory efficacy against Neofusicoccum laricinum, the causal pathogen of larch shoot blight. Using Rose Bengal medium as the basal medium, key fermentation factors, including carbon source, nitrogen source, inorganic salts, and culture conditions, were optimized. Under the optimized fermentation conditions, the sterile fermentation filtrate of T. hamatum T2 exhibited an inhibition rate of 78.8% against N. laricinum, compared with 28.0% obtained using the unoptimized PDA medium. In pot experiments, T2 treatment reduced disease incidence from 76.67% to 16.67%, with a control efficacy of 78.26%. In field trials, the control efficacies were 53.33% in 2024 and 60.26% in 2025. Following pathogen inoculation, T2 treatment significantly increased POD and SOD activities in larch needles, and promoted the accumulation of flavonoids and total phenols. T2 treatment also elevated GR activity, as well as the contents of non-structural carbohydrates, soluble sugars, starch, and proline. Response surface methodology effectively optimized the fermentation conditions of T2. This fungus enhances host resistance by inducing the plant antioxidant system and secondary metabolism, exhibiting promising potential for the biological control of larch shoot blight.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148881143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fungal Diseases Associated with Robusta Coffee (<i>Coffea canephora</i>) in Southern Thailand: Symptom Diversity, Pathogen Characterization, and Environmental Drivers.","authors":"Wanida Petlamul, Sawai Boukaew, Karistsapol Nooprom, Amornrat Chumthong","doi":"10.1094/PDIS-07-26-1384-RE","DOIUrl":"10.1094/PDIS-07-26-1384-RE","url":null,"abstract":"<p><p>Robusta coffee (Coffea canephora) production in tropical regions is increasingly constrained by fungal diseases associated with complex pathogen interactions and favorable environmental conditions. This study investigated symptom diversity, pathogen composition, pathogenicity, and environmental drivers associated with fungal infections in Robusta coffee plantations in southern Thailand. Field surveys were conducted in three commercial plantations located in Thung Lan Subdistrict, Khlong Hoi Khong District, Songkhla Province, Thailand, during February-July 2025. A total of 90 coffee trees were assessed using a stratified sampling approach, and disease symptoms affecting leaves, branches, flowers, and fruits were recorded. Nineteen representative disease symptoms were identified and grouped into major disease categories, including dieback complex, fruit rot/lesion complex, and leaf spot complex. The dieback complex exhibited the highest disease incidence and severity (65.4 ± 5.2% incidence; 58.7 ± 4.3% severity), followed by fruit rot/lesion complex (42.7 ± 4.8% incidence; 36.5 ± 3.8% severity) and leaf spot complex (38.2 ± 3.9% incidence; 29.8 ± 2.7% severity). A total of 10 morphologically distinct fungal isolates were recovered from symptomatic tissues. Molecular analyses identified Fusarium falciforme (95.41%), Lasiodiplodia/Diplodia sp. (99.37%), Lasiodiplodia theobromae (99.79%), and Lasiodiplodia sp. (81.35%). Pathogenicity assays demonstrated that all representative isolates induced disease symptoms on detached Robusta coffee leaves. Among them, F. falciforme showed the highest aggressiveness, producing lesions up to 4.73 cm within 7 days after inoculation. Environmental monitoring further indicated that elevated humidity and moderate temperature during the rainy season favored fungal disease development. These findings demonstrate that fungal diseases in Robusta coffee are driven by multi-pathogen interactions shaped by humid tropical environments, providing an important basis for integrated disease management and sustainable coffee production under changing climatic conditions.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148881134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}