Plant disease最新文献

{"title":"Development of a translation elongation factor 1-alpha (TEF) based TaqMan qPCR assay for <i>Diaporthe humulicola</i>, the causal agent of halo blight of hop.","authors":"Ross Joaquin Hatlen, Shay Szymanski, Nanci Adair, Qiurong Fan, Pooja Panwar, Roger Sysak, Laura Avila Miles, Douglas Higgins, J Alejandro Rojas, David H Gent, Timothy D Miles","doi":"10.1094/PDIS-11-24-2331-SR","DOIUrl":"https://doi.org/10.1094/PDIS-11-24-2331-SR","url":null,"abstract":"<p><p>Halo blight of hop, caused by <i>Diaporthe humulicola</i>, was first described in 2018 and is a major concern for growers in the eastern United States and Canada. This pathogen can cause quality and yield losses by desiccating hop cones, leading to shatter. However, traditional disease diagnosis is time-consuming, with morphological features taking up to 30 days to develop in culture. To address this issue, a quantitative polymerase chain reaction (qPCR) assay based on the translation elongation factor 1-alpha (TEF) gene was developed. We assessed capabilities and limitations of this assay for detection of <i>D. humulicola</i> in plant tissue and investigated aspects of the disease through: (1) testing of hop rhizomes for the presence of fungal pathogens; (2) determining the time required to detect <i>D. humulicola</i> in detached hop leaves; and (3) comparing plating methods with the qPCR assay to monitor <i>D. humulicola</i> in a hop yard. The limit of detection for the assay was 100 fg/µl of DNA. The assay showed no cross-reactivity with other hop pathogens, endophytes, or other Diaporthe species tested. Detection of <i>D. humulicola</i> occurred one day after inoculation. The assay detected <i>D. humulicola</i> in both asymptomatic and symptomatic rhizome tissue, but further investigation is required to determine the cause of the observed symptoms. The assay successfully detected the pathogen in individual hop cones and inflorescences throughout the season, with higher positive identification rates than culture-based assays. This assay will provide time-limited diagnosticians a tool for detection of <i>D. humulicola.</i></p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143974009","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":"First Report of Tomato leaf curl New Delhi virus Infecting Common bean (<i>Phaseolus vulgaris</i>) in China.","authors":"Kelei Han, Chao Ma, Wei Zhao, Dankan Yan","doi":"10.1094/PDIS-03-25-0592-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-03-25-0592-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Common bean (Phaseolus vulgaris), the largest legume vegetable worldwide for its edible dry seeds or green pods, is widely cultivated in China. In March 2023, common bean (cultivar Yulong No.3) showing virus-like symptoms, including leaf curling and plant stunting, were found in Mengcheng (Anhui Province, China), with an incidence rate about 2% (n ≈ 3,000) in an area of about 700 m2 (Fig. S1A). To assess the causal agent of the suspected disease, symptomatic leaves from eight common bean plants were collected and mixed for high-throughput RNA sequencing (RNA-seq) at Novogene Bioinformatics Institute Co., Ltd. (Tianjin, China). Total RNA extraction was performed using TRIzol Reagent (Invitrogen; Carlsbad, CA, USA), followed by cDNA library preparation with the Illumina TruSeq RNA Library Prep Kit v2 (Illumina; San Diego, CA, USA). Barcoded libraries were subsequently subjected to 150-bp paired-end sequencing on an Illumina HiSeq 4000 platform. A total of 9,778,308 clean reads were obtained, which were assembled into 107,133 contigs using Trinity (Version 2.8.5). The contigs were compared with the NCBI viral RefSeq database using BLASTx. The results show that the presence of two viral contigs displaying 99.85% and 99.63% identity to the DNA-A (accession No. OQ190946) and DNA-B (accession No. OQ190952) of Tomato leaf curl New Delhi virus (ToLCNDV) respectively, and no other viruses were identified. The whole genome of this ToLCNDV isolate was then amplified by rolling circle amplification (RCA) using phi29 DNA polymerase, and digested by restriction endonuclease (Sac Ⅰ for DNA-A and Hind Ⅲ for DNA-B). The digested fragments were cloned into the Litmus 28i vector and confirmed by DNA sequencing. The DNA-A and DNA-B sequences of the common bean-infecting ToLCNDV (ToLCNDV-HF23BC) were deposited in GenBank under the accession No. PP937118 (DNA-A, 2739 nt) and No. PP937119 (DNA-B, 2693 nt). BLASTn analysis of DNA-A showed that it had the highest similarity (99.85%, 2735/2739) with the isolate infecting tomato from Zhejiang province, China (accession No. OP356207; Li et al. 2023) and isolate infecting cucumber from Shanghai, China (accession No. OQ190946; Zeng et al. 2023); DNA-B had the highest similarity (99.70%, 2685/2693) with the isolate infecting melon from Shanghai, China (accession No. OQ190952; Zeng et al. 2023). The phylogenetic tree constructed based on DNA-A sequences showed that the DNA-A of ToLCNDV-HF23BC is closely related to isolates from other Asian countries, but more distantly to most of those from European (Fig. S2). In addition, to verify the infectivity of ToLCNDV isolate HF23BC, we constructed its infectious clone (Fig. S1B), and agrobacterium-infiltrated into Nicotiana benthamiana and common bean (Phaseolus vulgaris). At 10 days and 25 days post-inoculation (dpi), Nicotiana benthamiana and common bean plants exhibited typical leaf curling symptoms (Fig. S1C). ToLCNDV belongs to the genus Begomovirus of the family Geminivirida","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144018352","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":"Differential Infection Dynamics of <i>Verticillium dahliae</i> in Dicotyledonous (Cotton) versus Monocotyledonous (Maize) Host Systems.","authors":"Xin-Xin Liu, Shi-Jun Hao, Xiao-Bin Ji, Jun Wang, Steven J Klosterman, Xiaofeng Dai, Krishna V Subbarao, Wenxing Liang, Dandan Zhang, Jie-Yin Chen","doi":"10.1094/PDIS-01-25-0114-SC","DOIUrl":"https://doi.org/10.1094/PDIS-01-25-0114-SC","url":null,"abstract":"<p><p>Verticillium dahliae, a soil-borne fungal pathogen, infects and causes wilt symptoms in dicot but not in monocot plants. The precise sequence of events when V. dahliae infects monocots remain unclear. In this study, we confirmed on several different hosts that V. dahliae can cause typical Verticillium wilt symptoms on dicots but not monocots. Scanning Electron Microscope (SEM) and transmission electron microscope (TEM) studies indicate that V. dahliae germinates, expands and initially penetrates both cotton (dicot) and maize (monocot) roots. While V. dahliae has been previously shown to colonize the root cortex in monocots, our work clearly revealed that the pathogen penetrates into the xylem but is unable to survive in the maize roots during early stages of colonization. Rather, the conidia and mycelia breakdown in maize, and remains of shrunken cells persist in the roots. Collectively, our results provide new clues on the sequence of events that occur when V. dahliae infects monocots versus dicots and may underlie Verticillium wilt symptoms on dicots but not monocots.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144037687","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":"Pathogen Composition and Fungicide Sensitivity in Rice Spikelet Rot Disease.","authors":"Jiaqi Chen, Xiping Cao, Xiaolong Fu, Mingguo Zhou, Changjun Chen, Xiushi Song","doi":"10.1094/PDIS-09-24-1807-RE","DOIUrl":"10.1094/PDIS-09-24-1807-RE","url":null,"abstract":"<p><p>Rice spikelet rot disease (RSRD) is an emerging threat to rice crops, with sporadic but severe outbreaks in China in recent years. The composition of its pathogenic fungi has not been consistently identified, and chemical control methods remain unclear. This study aims to characterize the pathogen species responsible for RSRD and develop effective control strategies. Regional variations in disease symptoms and pathogen compositions were analyzed, which led to the identification of six novel pathogens: <i>Fusarium tanahbumbuense</i>, <i>Alternaria gaisen</i>, <i>Curvularia verruculosa</i>, <i>C. brachyspora</i>, <i>C. muehlenbeckiae</i>, and <i>C. hominis</i>. The pathogenic composition of RSRD exhibited considerable variation across different latitudes within China. Specifically, <i>Alternaria</i> spp. predominated in Heilongjiang and Liaoning provinces, whereas <i>Fusarium</i> spp. and <i>Curvularia</i> spp. were more prevalent in Hainan and Fujian provinces. In contrast, <i>Fusarium</i> spp. and <i>Alternaria</i> spp. were the dominant pathogens in Anhui and Jiangsu provinces. Furthermore, an assessment of the sensitivity of these predominant pathogens to four chemical compounds was conducted, which led to the identification of potential fungicides for effective disease control. This research provides valuable insights into the pathogenic profile of RSRD across different regions and offers strategic recommendations for fungicide-based management of the disease.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":"PDIS09241807RE"},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142625751","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":"Unexpected diversity of <i>Pectobacterium</i> species responsible for causing bacterial soft rot on Chinese flowering cabbage in Guangdong province, China.","authors":"Shanwen Ding, Zijun Ma, Guobing Lan, Yafei Tang, Zhenggang Li, Lin Yu, Zifu He, Xiaoman She","doi":"10.1094/PDIS-12-24-2601-SR","DOIUrl":"https://doi.org/10.1094/PDIS-12-24-2601-SR","url":null,"abstract":"<p><p>Chinese flowering cabbage (Brassica parachinensis), commonly known as Choi-sum, is an important bolting stem vegetable and mainly cultivated in the Guangdong province of China. Bacterial soft rot of Choi-sum is a major disease that is capable of causing widespread outbreaks under conducive conditions. Historically, the disease was attributed to the Pectobacterium genus, but the specific species were not identified clearly. To investigate the species and diversity of the species associated with soft rot of Choi-sum, 72 bacterial isolates were collected from symptomatic plants in three cities (seven counties or districts) of Guangdong province between 2021 to 2022. Field incidence ranged from 1.5% to 45%. These isolates were identified via physiological and biochemical characteristics, molecular analyses including 16S rRNA sequencing, and multilocus sequence analysis (MLSA) and confirmed via Koch's postulates. The isolates were identified as Pectobacterium brasiliense (63), P. carotovorum (4), P. aquaticum (2), P. quasiaquaticum (1), P. colocasium (1) and P. aroidearum (1). Host-range tests showed that all strains except for P. aquaticum GDPAq2, which was not pathogenic to wax gourd, were pathogenic to 'Zengcheng Choi-sum', 'Sijiu Choi-sum', potato plants, potato tubers, tomato, and wax gourd, displaying typical symptoms of bacterial soft rot. These results revealed an unexpected diversity of Pectobacterium species associated with soft rot of Choi-sum in China. To our knowledge, this is the first report providing detailed identification and diversity of the soft rot pathogens on Choi-sum which may affect future management strategies.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144037877","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":"Developing PCR-based assays for detecting Pea seed-borne mosaic virus (PSbMV) in plants, seeds, and its aphid vector, <i>Acyrthosiphon pisum</i>.","authors":"Dinesh Babu Paudel, Ningxing Zhou, Ana Priscilla Montenegro-Alonso, Grace Onu-Odey, Tyler Hartl, M Hossein Borhan, Sean Prager","doi":"10.1094/PDIS-12-24-2709-RE","DOIUrl":"https://doi.org/10.1094/PDIS-12-24-2709-RE","url":null,"abstract":"<p><p>Pea seed-borne mosaic virus (PSbMV) poses a major threat to global pulse production. This virus, transmitted through seeds, can spread within fields via insect vectors, especially pea aphids (Acyrthosiphon pisum), in a non-persistent manner. To mitigate the risks associated with PSbMV, it is crucial to plant virus-free seeds, detect the virus at an early stage, and implement effective control measures for the vectors, given that most commercial pulse cultivars are vulnerable to the virus. This study designed and assessed multiple primers for PCR-based virus detection and demonstrated their capability to identify PSbMV isolates in infected plant tissues. The primers successfully detected PSbMV in dried plant tissues and in aphids collected from infected plants, even after being stored at room temperature for up to three months. Furthermore, a hydrolysis probe-based assay was developed, and their effectiveness for quantitative PCR (qPCR), digital PCR (dPCR), and droplet digital PCR (ddPCR) was evaluated. Our results showed high sensitivity and linearity of the assay, capable of detecting PSbMV at concentrations as low as 22 copies per reaction mix using digital PCRs. Our findings underscore the effectiveness of the developed primers and assay for the rapid and sensitive detection of PSbMV isolates in a variety of plant tissues, aphids, and seed samples, offering improved tools for disease monitoring and management in agricultural settings.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143993939","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":"First Recorded Parasitism of <i>Keteleeria evelyniana</i> by <i>Cuscuta chinensis</i> in Yunnan, China.","authors":"Guansong Yang, Mingwei Hong, Yu Qu, Shu Han","doi":"10.1094/PDIS-11-24-2396-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-11-24-2396-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The genus Cuscuta, also known as dodder, comprising numerous holoparasitic plant species, exhibits a broad distribution across China, where it is recognized for its detrimental effects on indigenous florae (Narukawa, et al, 2021). Within this genus, &lt;i&gt;Cuscuta chinensis&lt;/i&gt; stands out as a species of particular concern due to its potential to imperil a diverse array of plant species (Tang, et al, 2024). Notably, there is a dearth of literature documenting its parasitic interactions with &lt;i&gt;K. evelyniana&lt;/i&gt;, a conifer species that is both ecologically and economically significant (Tang, et al, 2024). The ecological services provided by this species, along with the high quality of its timber, highlight its importance in both ecological and economic contexts. In our 2023 field expeditions, we documented for the first time the parasitic interaction between &lt;i&gt;C. chinensis&lt;/i&gt; and &lt;i&gt;K. evelyniana&lt;/i&gt; in Kunming, Yunnan Province, China (102°46'12″, 25°05'23″). The &lt;i&gt;K. evelyniana&lt;/i&gt; plants parasitized by &lt;i&gt;C. chinensis&lt;/i&gt; showed symptoms including chlorosis, wilting, and defoliation. The specimens collected presented yellow, leafless, twining stems with haustoria at the nodes, characteristic of &lt;i&gt;C. chinensis&lt;/i&gt;. The species possess an umbel inflorescence containing 2 to 10 white flowers, each with a subtle pentamerous corolla. Morphological assessment identified the specimen as &lt;i&gt;C. chinensis&lt;/i&gt;. We surveyed a 2.8-hectares area around an infected &lt;i&gt;K. evelyniana&lt;/i&gt;, examining approximately 20 plants, and found only one instance of &lt;i&gt;C. chinensis&lt;/i&gt; infection. Given its rarity and the presence of &lt;i&gt;C. chinensis&lt;/i&gt; on other species outside this area, we consider &lt;i&gt;K. evelyniana&lt;/i&gt; a rare host for this dodder. To ascertain the species identity with greater certainty, we sequenced the complete chloroplast genome using Illumina sequencing technology. Total genomic DNA was extracted from specimen stems and subjected to whole-genome sequencing. The chloroplast genome was subsequently assembled and annotated using the PGA (Plant Genome Annotation) tool (Qu et al. 2019), resulting in a complete chloroplast genome sequence that was deposited in GenBank (Accession number: PQ585822). The chloroplast genome has a length of 86,800 bp. BLAST analysis confirmed the species of the Dodder as &lt;i&gt;C. chinensis&lt;/i&gt;, as it exhibited a 99.85% similarity with the previously uploaded sequence (Accession number MH780079), with 100% query coverage. Phylogenetic analyses (maximum likelihood with 1,000 bootstrap replicates and Bayesian inference with 2,000,000 MCMC generations, sampling every 1,000 generations) confirmed the specimen as &lt;i&gt;C. chinensis&lt;/i&gt;. Ultimately, the specimen of the dodder recovered in Yunnan Province was classified as &lt;i&gt;C. chinensis&lt;/i&gt;, employing a holistic approach that considered morphological attributes, sequence homology, and phylogenetic affiliations. A voucher specimen of &lt;i&gt;K. evelyniana&lt;/i&gt;, parasitized by &lt;i&gt;C. chinensis&lt;/","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144007699","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":"Estimation of Peanut Yield Losses Due to Early Leaf Spot on Spanish Cultivars in Oklahoma: A 26-year Summary.","authors":"Maira Duffeck, John Damicone, Kenneth Jackson, Rebecca S Bennett, Kelly Chamberlin, Todd Baughman","doi":"10.1094/PDIS-09-24-1815-RE","DOIUrl":"https://doi.org/10.1094/PDIS-09-24-1815-RE","url":null,"abstract":"<p><p>Early leaf spot, caused by Passalora arachidicola, is the most prevalent and yield-limiting foliar disease affecting peanuts in Oklahoma. Quantifying yield losses associated with end-of-season defoliation caused by early leaf spot is essential to evaluate the effectiveness of currently deployed control strategies. To that end, a meta-analysis was conducted to assess the heterogeneity in the relationship between ELS defoliation (%) and peanut yield (kg/ha) of Spanish cultivars (A. hypogaea ssp. fastigiata var. vulgaris) in Oklahoma. Data were mined from fungicide efficacy trials performed in small plots across Oklahoma between 1990 and 2023. Studies (n=49) over 26 years met the criteria of at least a 10% difference between the minimum and maximum defoliation within the study. A random-coefficient model was successfully fitted to the data using maximum likelihood. The estimates of population-average of the intercept and slope were β ̂_0 = 4,296.6 kg/ha (SE = 131.9) and β ̂_1= 13.7 kg/ha (SE = 0.9), respectively. The damage coefficient, which represents the percentage reduction in yield per percentage point increase in crop defoliation, was 0.32%. These results allow the prediction of yield loss given for end-of-season defoliation levels and guide peanut producers and researchers in Oklahoma regarding modifying production practices and developing decision-making tools to mitigate losses due to early leaf spot defoliation.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143993270","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":"A phylogeny of the tymoviruses, sensu stricto, and its global interpretation in space and time.","authors":"Adrian J Gibbs, Segundo Fuentes, Ian Adams, Mohammad Hajizadeh, Karima Ben Mansour, Paul L Guy, Cesar Fribourg, Heiko Ziebell, Jan Kreuze, Adrian Fox, Roger Anthony Charles Jones","doi":"10.1094/PDIS-01-25-0061-RE","DOIUrl":"https://doi.org/10.1094/PDIS-01-25-0061-RE","url":null,"abstract":"<p><p>Maximum likelihood (ML) phylogenies of 109 tymoviruses, including three obtained directly from metagenomes, were calculated from all three open reading frames separately, but the concatenated sequences of their replicase and coat protein genes gave the most representative trees. ML phylogenies were also calculated from all recorded tymomvirus coat protein genes, and from datasets of the turnip yellow mosaic virus cluster, and separately of tomato yellow blotch, Andean potato latent and Andean potato mild mosaic viruses. These phylogenies showed that the basal divergence of tymoviruses occurred in a population infecting Eurasian brassicas (rosids), and more recently, one of the basal lineages diversified and adapted to infect some solanaceous (asterid) plants and crops of Central and South America. Heterochronous dating of the phylogenies failed, but heuristic comparisons based on patristic distances, branching patterns and external events suggested that the 'most recent common ancestor' of all known tymoviruses existed before the last Ice Age. Some lineages reached the Americas about 15,000 years ago. However, most spread of the few tymoviruses now found on more than one continent occurred during the past two centuries. The only recombinants were two sequences of Chiltepin yellow mosaic virus both with Nemesia ring necrosis virus as minor parent. Population genetic analysis found significant evidence of population contraction in the tymovirus populations infecting asterid hosts in the Americas. It also found the replicase and coat protein genes were significantly negatively selected. By contrast, the overlapping movement protein genes were positively selected which may help them adapt to new host species, including infecting economically significant crops. This knowledge about tymoviruses is important to plant biosecurity authorities.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144036599","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":"Species and Distribution of <i>Fusarium</i> Causing Ginseng Root Rot and Antifungal Efficacy of Captan and Hymexazol against <i>F.</i> spp. in China.","authors":"Jun Wang, YunMing Wang, Ying Wang, YanJia Li, Lina Yang, Bao Hui Lu, Changqing Chen, Ronglin He, Xue Wang, Jie Gao","doi":"10.1094/PDIS-03-25-0491-RE","DOIUrl":"https://doi.org/10.1094/PDIS-03-25-0491-RE","url":null,"abstract":"<p><p>Fusarium root rot on ginseng (FRRG) is an important root disease that seriously affects ginseng (Panax ginseng) yield and quality. However, the species categories and distribution of Fusarium causing ginseng root rot in China have not been systematically examined. A total of 571 pure Fusarium isolates were obtained from 2018 to 2019 from 14 ginseng-producing regions in Jilin, Liaoning, and Heilongjiang Provinces, China. Based on multi-locus sequence analysis of ITS-tef1-rpb2 and morphological characteristics, 571 Fusarium isolates were identified as F. oxysporum (accounting for 47.46% of the total isolates), F. solani (35.38%), F. equiseti (5.78%), F. proliferatum (2.80%), F. cerealis (1.75%), F. semitectum (1.75%), F. acuminatum (1.75%), F. redolens (1.58%), F. verticillioides (1.05%), and F. graminearum (0.70%). Among them, F. oxysporum and F. solani were the dominant species, and F. graminearum and F. verticillioides were first recorded on ginseng in China. The fungicides captan and hymexazol were tested in vitro for their inhibitory activities against ten Fusarium species. All Fusarium species displayed enhanced sensitivity to captan compared with hymexazol. The protective effects of captan against ginseng root rot caused by F. oxysporum (FoRRG) ranged from 94.07% to 97.78% at concentrations of 200, 400, and 600 µg·mL-1; however, its curative effects were much lower, ranging from 29.63% to 35.56%. In comparison, hymexazol exhibited protective effects of only 24.00% to 52.00% and curative effects of 16.00% to 45.33% at concentrations of 600 to 1000 µg·mL-1. In addition, microconidia were highly sensitive to both fungicides, compared with mycelia and macroconidia.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143976174","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}