Plant disease最新文献

{"title":"First Report of Sclerotinia Blight Caused by <i>Sclerotinia sclerotiorum</i> on <i>Calendula officinalis</i> in China.","authors":"Junlin Chen, Tun Wu, Shuang An, Xia Fan, Ruiling Lyu","doi":"10.1094/PDIS-04-25-0789-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-04-25-0789-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Calendula officinalis is widely cultivated in China for its medicinal and ornamental value. In December 2023, symptoms of an unknown sclerotinia-like disease were observed on C. officinalis plants grown on the campus of Huanggang Normal University in the Huanggang area of Hubei, China (30°44'91″ N, 114°92'31″E). Affected leaves and petioles exhibited chlorosis, with internal rotting initiating from the leaf lamina. Dense white mycelial mats developed on infected tissues, particularly leaves and stems. Leaf tips progressively turned grayish, curled, and withered, while petioles displayed grayish discoloration and necrosis, ultimately causing corolla drooping. Severely infected plants eventually died, with approximately 40% of 1,000 monitored plants exhibiting these symptoms. Diseased tissues were excised and immersed in a sodium hypochlorite solution (1%) for approximately 10 s, then washed in sterilized water. Small pieces of affected leaves, petioles, and stems were successfully cultured on potato dextrose agar (PDA) medium, incubated at 25°C. Twenty Sclerotium-like isolates were obtained through mycelial tip isolation. Isolate HGNU2023-P1 displayed white, tightly adherent aerial mycelium and produced 10~20 irregular sclerotia (3.65 ± 0.8 mm in size, mean ± SD, n = 100) near the edge of the petri dishes after 15 d of incubation at 25°C under alternating 12-hour light/dark cycles. For molecular identification, DNA from two representative isolates (HGNU2023-P1 and HGNU2023-S1) were used to amplify the internal transcribed spacer (ITS) region with primers ITS1/ITS4, the glyceraldehyde 3-phosphate dehydrogenase (G3PDH) gene with primers G3PDHfor/G3PDHrew (Zhang et al. 2021), and the heat shock protein 60 (HSP60) gene with primers HSP60for/HSP60rew (Yin Fuqiang et al. 2024). The gene products were sequenced at Wuhan JinKairui Biological Co., Ltd., and the obtained sequences were submitted to the NCBI database under accession numbers PV330002, PV330003, and PV344707 to PV344710. The sequences exhibited 99%~100% identity with those of Sclerotinia sclerotiorum in GenBank. A phylogenetic tree was constructed using the Neighbor-Joining (NJ) method in MEGA11 based on concatenated ITS, G3PDH, and HSP60 sequences. Pathogenicity of the isolate was evaluated on 18 two-month-old C. officinalis plants. Three plants were inoculated with 5-mm-diameter mycelial plugs of HGNU2023-P1 grown on PDA for 3 days, while control plants received sterile PDA plugs, with three replicates. All seedlings were incubated at 25°C and 90% relative humidity. Within 2 dpi, inoculated plants developed symptoms consistent with field observations, whereas controls remained asymptomatic. S. sclerotiorum was consistently reisolated from decayed plant tissue, fulfilling Koch's postulates. S. sclerotiorum is known to severely threaten numerous Asteraceae hosts (Underwood et al. 2022). This is the first report of S. sclerotiorum causing Sclerotinia blight on Calendula officinalis in Chi","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302633","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 a New Species, <i>Trichomerium puerense</i>, Causing Sooty Mold on <i>Coffea arabica</i> in China.","authors":"Li Lu, Jingya Yang, Meiyan Han, Yina Liu, Samantha C Karunarathna, Ruvishika S Jayawardena, Haiying Liao, Kevin Hyde, Abdallah Elgorban, Dong-Qin Dai, Saowaluck Tipbromma","doi":"10.1094/PDIS-04-25-0726-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-04-25-0726-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Coffea arabica (Rubiaceae) is one of the most popular coffees worldwide (Zhu et al. 2024). In April 2024, symptoms of sooty mold appeared in the largest coffee-growing region in Yunnan Province, China (22°66'N; 100°96'E; 1073 m). The disease initially appears as a black powdery coating on coffee leaves, cherries, and twigs, later forming a thick, adherent layer that cracks or peels off under dry conditions. A field survey was conducted over approximately 20 hectares (300 mu) of coffee plantations, and fresh symptomatic leaves were collected and observed. Micro and macro photographs were prepared for photomicrography. Pure cultures were obtained following the methods in Senanayake et al. (2020). Pure cultures were grown on potato dextrose agar at 28 °C for one month and used for DNA extraction and the pathogenicity test. Morphology and multi-locus phylogeny confirmed that the sooty mold is a distinct new species in Trichomerium: Trichomerium puerense L. Lu, K.D. Hyde & Tibpromma, sp. nov. MycoBank number: MB 857498. Etymology: The epithet refers to the location \"Pu'er\" from where the holotype was collected. Holotype: MHZU 24-0582. It forms black sheets which are superficial and thin, cover the leaves, and are composed of cylindrical hyphae. Superficial hyphae 4-6 μm wide also form, are septate, constricted at the septum, unbranched, brown, dense, with cylindrical hyphal cells, and produce guttules. Ascostromata are 100-150 × 120-150 μm, superficial, solitary, globose to subglobose, and brown to black. Setae are 40-80 × 4-7 μm, straight or flexuous, brown, and septate. Peridia are 15-20 μm wide, thick-walled, hyaline to brown, and comprised of textura angularis cells. Asci are 45-70 × 20-28 μm (n = 30), 8-spored, bitunicate, ellipsoid to clavate, or cylindrical, with a short pedicle and an ocular chamber. Ascospores are 20-25 × 7-10 μm (n = 10), fusoid to ellipsoid, hyaline, 1-3-septate, constricted at the septum, with narrow ends, somewhat tapering towards the base when mature, smooth-walled, and produce guttules. DNA fragments were amplified and sequenced with ITS, LSU, and SSU (Hyde et al. 2020). The sequences were deposited in GenBank (ITS, PV056513, PV056514; LSU, PV056517, PV056518; SSU, PV056515, PV056516). The morphology of the collection (sm4) was consistent with Trichomerium (Rana et al. 2019; Hyde et al. 2020). Maximum likelihood and Bayesian Inference analyses on CIPRES confirmed that our isolates formed a distinct lineage within Trichomerium with 100% ML/1.00 PP statistical support. Based on morphology and phylogeny, sm4 was identified as a new species, T. puerense. To fulfill Koch's postulates (Xu et al. 2019), ten healthy arabica coffee plants were selected. Five plants were inoculated with two 3-mm fungus plugs per leaf sheath, and the other five plants were inoculated with PDA agar plugs (control group). All plants were sealed in transparent plastic bags and incubated in a greenhouse at 26 ± 2 °C for 28 days, with daily moist","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302630","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 Lettuce Chlorosis Virus Infecting Chinese Cabbage in China.","authors":"Yiru Li, Yi An Liang, Jun Li, Chao Zhang","doi":"10.1094/PDIS-03-25-0643-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-03-25-0643-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Chinese cabbage (Brassica rapa L. ssp. pekinensis) is a cruciferous vegetable of significant agricultural importance in China, valued for its high yield and nutritional benefits (Yun et al., 2021). However, viral diseases pose a serious threat to its production, affecting both yield and quality (Wang et al., 2024). In November 2021, leaf samples exhibiting viral-like symptoms, including chlorosis, leaf curling, and stunting, were collected from a Chinese cabbage field in Baoding, Hebei Province, China. Total RNA extracted from symptomatic leaves of 8 Chinese cabbages with viral symptoms using TRIzol Reagent (Invitrogen) was pooled to generate composite samples. These combined RNA samples were then processed for library construction and analyzed by high-throughput sequencing (HTS) on the Illumina MiSeq platform to identify viral pathogens. A total of 15,872,109 raw reads were generated and has been deposited in Sequence Read Archive (SRR31969092), of which 15,681,883 (98.80%) were retained as clean reads after quality filtering. Subsequently, 7,504,572 reads were mapped to the reference genome (http://www.bioinformaticslab.cn/EMSmutation/home/). Small RNAs (sRNAs) ranging from 18 to 26 nucleotides in length were isolated and assembled into 1,079 contigs using Velvet and PFOR. Contigs were annotated and classified using the Virus RefSeq Nucleotide and Virus RefSeq Protein databases, with sequence alignment performed using BLAST. Analysis revealed the presence of lettuce chlorosis virus (LCV), a member of the genus Crinivirus, family Closteroviridae (Salem et al.,2009). The bipartite single-stranded RNA genome comprises RNA1 (8.59 kb, NC_012909.1) encoding 8 putative proteins including RNA-dependent RNA polymerase (RdRp), and RNA2 (8.56 kb, NC_012910.1) containing 7 open reading frames (ORFs) such as the coat protein (CP) gene. A total of 996 sRNAs were mapped to various positions of the LCV genome, covering 7.11% of the viral genomic sequence. Through BLAST, we found that the similarity range of the viral sequences to LCV isolate CN is from 93.33% to 100%. Specifically, LCV RNA1 and RNA2 were identified with 272 and 219 mapped reads, respectively. To confirm the presence of LCV, RT-PCR was performed using specific primers (F-cp: 5'-ATGGGTGATAGCAAAGAAAC-3', R-cp: 5'-TTATTTACTGCAACCCCCTG-3') targeting the CP gene. A 753-bp fragment of the CP gene was amplified and sequenced. BLASTn analysis showed 98.7% nucleotide sequence identity with an LCV isolate CN segment RNA2 on Periwinkle (accession no. KY430286.1). To the best of our knowledge, this is the first report of LCV infecting Chinese cabbage worldwide, and also the first report of LCV in the region north of the Yangtze River in China (Zhao et al., 2018) (Tian et al., 2018). So far, the hosts of the LCV discovered in China include Periwinkle and Madagascar periwinkle [Catharanthus roseus (L.)] and Tobacco plants (Nicotiana tabacum cv. Samsun NN). These findings expand the known host range of ","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302632","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":"Surveys of <i>Magnaporthe oryzae</i> Genotypes in Breeding Stations and Commercial Rice Fields in Arkansas, Louisiana, and Puerto Rico from 2017 to 2019.","authors":"Yixiao Huang, Yulin Jia, Yeshi Wamishe, Melissa H Jia","doi":"10.1094/PDIS-03-24-0652-RE","DOIUrl":"10.1094/PDIS-03-24-0652-RE","url":null,"abstract":"<p><p>Major resistance (<i>R</i>) gene-mediated resistance to rice blast fungus <i>Magnaporthe oryzae</i> is often overcome by the fungus because of the occurrences of new races with altered corresponding avirulence (<i>AVR</i>) genes. In this study, blast-diseased rice tissue samples were collected from breeding stations and commercial rice fields in Arkansas, Louisiana, and Puerto Rico during 2017 to 2019 to determine the efficacy of major <i>R</i> genes <i>Pi-ta/Ptr</i>, <i>Pik</i>, <i>Pizt</i>, <i>Pi9</i>, and <i>Pi33.</i> A total of 185 blast isolates were isolated from the diseased tissue samples to examine the existence of <i>AVR</i> genes <i>AVR-Pita1</i>, <i>AVR-Pib</i>, <i>AVR-Pik</i>, <i>AVR-Pizt</i>, <i>AVR-Pi9</i>, and <i>ACE1.</i> Genotyping of the isolates was conducted using 10 simple sequence repeat (SSR) markers. <i>AVR-Pizt</i> and <i>AVR-Pita1</i> were found in all isolates, suggesting that major <i>R</i> genes <i>Pizt</i> and <i>Pi-ta</i> are still effective to prevent infections by these isolates. Among the 185 isolates, 117 contained all six <i>AVR</i> genes and 68 contained three to five <i>AVR</i> genes, suggesting various degrees of race shift in these isolates. The SSR data revealed endemicity in genetic backgrounds among Arkansas isolates but migration in isolates between Louisiana and Puerto Rico. STRUCTURE analysis of the SSR data suggested three major clusters with 46 combinations. The Arkansas isolates showed a high genetic diversity, but one genotype dominated. The Louisiana isolates were also genetically diversified without any obvious predominant group. The Puerto Rico isolates had the lowest heterozygosity. These data reveal contemporary genetic changes of the rice blast fungus and are useful for guiding the deployment of major <i>R</i> genes in these regions.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":"PDIS03240652RE"},"PeriodicalIF":4.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142922594","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 leaf spot caused by <i>Alternaria alternata</i> on <i>Tetrastigma hemsleyanum</i> in China.","authors":"Jiao Ren, Gaolei Cai, Peng Zhang, Han Zhang, Lu Wang, Dongfang Ma","doi":"10.1094/PDIS-03-25-0568-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-03-25-0568-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Tetrastigma hemsleyanum Diels & Gilg (Vitaceae) is a traditional Chinese medicine species widely distributed in the valley regions of Hubei, China. T. hemsleyanum has the effects of antitumor, anti-inflammatory, antiviral and detoxification (Wang et al. 2024). In October 2023, dark brown spots were observed that up to 50% on the leaves of T. hemsleyanum plants cultivated in a 30 m2 nursery in Shiyan (32.62ºN, 110.78ºE), Hubei, China. Initially, small, dark-brown lesions appeared in the middle of leaves. As the symptoms progressed, necrotic lesions expanded or fused into large, dark brown spots with irregular shape. Five leaf pieces (5 mm×5 mm) from the disease margin were sampled, and were disinfected in 70% ethanol for 20 s, in 1.5% NaClO for 2 min, washed with sterilized water for three times, and were placed on potato dextrose agar (PDA) plates, respectively. The plates were stored at 25 ℃ in the dark. After 7 days, five colonies with similar morphological characteristics were obtained on PDA and two representative isolates RJC1 and RJC3 were used for further study. The RJC1 and RJC3 on PDA initially had white mycelium, which turned light brown after 3 days, then gradually turned black brown after 7 days. Conidia were brown, drumstick-like or clavate, 1-5 transverse and 0-3 longitudinal septa, with darker in septa, usually 12.19-34.07×6.17-15.57 μm in size (n=50). The isolates were identified as Alternaria sp. (Simmons 2007) based on the morphological characteristics. For accurate classification, genomic DNA of two representative isolates was extracted from mycelium after 7 days on PDA using a DNA extraction kit (TSINGKE Biotech Co., Ltd.). Internal transcribed spacer (ITS), translation elongation factor 1-alpha (TEF1) genes were amplified and sequenced using primer pairs ITS1/ITS4 (White et al. 1990) and EF1-728F/EF1-986R (Carbone and Kohn 1999). A BLASTn search revealed that the ITS regions (accessions PQ844677, PQ844678) showed 99.81% and 100% homology with Alternaria alternata Aa1 (OK036714) and PPRI: 26401 (MT505877). The TEF1 regions (accessions PQ876358, PQ999190) showed 99.59% and 99.64% homology with Alternaria alternata Zb-SD1 (OQ585964) and SF-004 (ON055375). A phylogenetic tree was constructed using the neighbor-joining method in MEGA 7. The isolates RJC1 and RJC3 belonged to the same clade with A. alternata, supported by a value of 100%. Based on the morphological characteristics and molecular analysis, RJC1 and RJC3 were identified as A. alternata. For pathogenicity test, five healthy T. hemsleyanum plants were inoculated with a conidial suspension (1.0×105 conidia/mL) and grown in a greenhouse at 25 ℃ with 12 h light/12 h dark. The other five plants were inoculated with sterile water as control. The inoculation was performed three times. Dark brown lesions similar to those in the samples were appeared on leaves 7 days after inoculation, but no symptoms were observed on the control leaves. The same fungus was reisolated fro","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302631","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 <i>Botryosphaeria dothidea</i> Causing Fruit Soft Rot on <i>Pyracantha fortuneana</i> in China.","authors":"Yan Chen, Fenghanqian Bi, Yingxian Yang, Renjie Yang, Xiaoqiong Guo, Yanguo Xu","doi":"10.1094/PDIS-03-25-0682-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-03-25-0682-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;&lt;i&gt;Pyracantha fortuneana&lt;/i&gt; (Maxim.) H. L. Li is mainly distributed in the southern and southwestern regions of China, locally called \"Jiu Bing Liang\". Recently, it has gained attention for its antioxidant and anticancer properties, positioning it as a promising functional food in China (Yao et al. 2020). On October 10, 2024, fruit soft rot of &lt;i&gt;P. fortuneana&lt;/i&gt; was observed on the campus of Qujing Normal University (103.75°E, 25.52°N), Qujing City, Yunnan Province, with an incidence of 20%. The infected fruits exhibited shrinkage and soft rot, accompanied by a change in color from red to black. Small segments (0.2 × 0.5 cm) were excised from the junction of disease-healthy tissue of infected fruits, soaked in 75% ethanol for 4 minutes, rinsed in sterile water three times, and cultured on potato dextrose agar (PDA) at 28°C in the dark for 24 hours. A thin layer of white mycelium emerged around the tissue, which was subcultured onto fresh PDA medium. After 3 days, the colony center turned yellowish-gray, and the mycelium covered the entire 9 cm diameter of the medium after four days. After 10 days, the colony had turned completely blue-black. Eight strains with similar morphological characteristics were isolated, and one representative isolate (BHA) was used for morphological and molecular characterization. To observe conidia, culture conditions were modified by alternating temperatures (24°C and 28°C), exposure to alternating ultraviolet and visible light, and cultivation on nutrient-poor agar (SNA). Despite extending the observation period to 45 days, no conidia were detected. Molecular identification was performed using specific primers: ITS1/ITS4, EF1-728F/EF1-986R, and Bt2a/Bt2b to amplify the internal transcribed spacer (ITS1-5.8S-ITS2) region, the translation elongation factor (&lt;i&gt;EF1-α&lt;/i&gt;) gene, and the beta-tubulin (&lt;i&gt;β-tubulin&lt;/i&gt;) gene, respectively (Marsberg et al. 2017; Slippers et al. 2004). The sequences were deposited in GenBank under accession numbers PQ895675 (ITS), PV082023 (&lt;i&gt;EF1-α&lt;/i&gt;), and PV068288 (&lt;i&gt;β-tubulin&lt;/i&gt;). A BLAST search of GenBank showed that the ITS, &lt;i&gt;EF1-α&lt;/i&gt;, and &lt;i&gt;β-tubulin&lt;/i&gt; sequences of this isolate were similar to those of &lt;i&gt;Botryosphaeria dothidea&lt;/i&gt; KY393137 (identity = 511/511; 100%), MN548726 (identity = 269/269; 100%), and MK511445 (identity = 434/434; 100%) respectively. A maximum-likelihood and Bayesian posterior probability-based phylogenetic analyses using PhyloSuite version 1.2.3 with the concatenated sequences (ITS, &lt;i&gt;EF1-α&lt;/i&gt;, &lt;i&gt;β-tubulin&lt;/i&gt;) placed BHA in the clade of &lt;i&gt;B. dothidea&lt;/i&gt;. Based on the multigene phylogeny and morphology, BHA isolate was identified as &lt;i&gt;B. dothidea&lt;/i&gt;. Pathogenicity was confirmed by inoculating PDA plugs containing mycelium onto both wounded and unwounded fruits of &lt;i&gt;P. fortuneana&lt;/i&gt;. After seven days, symptoms developed exclusively on wounded fruits. The pathogen was reisolated from the infected tissues and reconfirmed as &lt;i&gt;B. dothid","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302718","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":"Role of Soil Moisture in Disease Development of Charcoal Rot of Strawberries Caused by <i>Macrophomina phaseolina</i>.","authors":"Lindsey Pedroncelli, Andre Biscaro, Alexander I Putman","doi":"10.1094/PDIS-05-24-1131-RE","DOIUrl":"10.1094/PDIS-05-24-1131-RE","url":null,"abstract":"<p><p>Charcoal rot, caused by the soilborne fungus <i>Macrophomina phaseolina</i>, is one of the most economically important diseases affecting strawberry (<i>Fragaria</i> × <i>ananassa</i>) production in California. Previous studies on nonstrawberry hosts have shown that proper soil moisture management can limit pathogen colonization of plants and decrease disease severity. We performed field and greenhouse studies for two seasons with the objective of investigating the role of soil moisture in disease development and management of charcoal rot of strawberries. Bare-root transplants of cultivars Monterey and Fronteras were inoculated or not inoculated and maintained at a high, optimal, or low soil moisture level using tensiometers. Randomly selected plants from each treatment were sampled for pathogen colonization every 4 weeks after planting, and all plants were visually rated for disease severity every 2 weeks after symptom onset. In both seasons, low soil moisture significantly increased charcoal rot mortality among inoculated plants compared with optimal soil moisture by 16 and 24 percentage points, respectively. In the first season, mortality was significantly lower in the high- compared with the optimal-soil-moisture treatment. Colonization of crowns was increased by low soil moisture among inoculated plants in the first season, but soil moisture did not influence root colonization in either year of the study. In the greenhouse, charcoal rot severity was highest in the low-soil-moisture treatment. These results indicate that soil moisture has a limited influence on colonization of strawberries by <i>M. phaseolina</i> and that maintaining optimal soil moisture can help prevent excess charcoal rot mortality.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":"PDIS05241131RE"},"PeriodicalIF":4.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818947","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":"Isolation and Identification of Six Newly Recorded Wheat Fusarium Crown Rot-Associated <i>Fusarium</i> Species.","authors":"Guoping Ma, Kai Qi, Yueli Zhang, Bo Zhang, Hang Jiang, Liguo Ma, Junshan Qi","doi":"10.1094/PDIS-10-24-2130-RE","DOIUrl":"10.1094/PDIS-10-24-2130-RE","url":null,"abstract":"<p><p>Fusarium crown rot (FCR) has become one of the most serious diseases affecting wheat production worldwide. To date, many <i>Fusarium</i> species associated with wheat FCR disease have been reported. To gain a deeper understanding of <i>Fusarium</i> species diversity associated with wheat FCR, extensive research was conducted to identify different <i>Fusarium</i> species. A total of 194 diseased wheat samples were collected from Dezhou, Heze, Jining, Linyi, Qingdao, Rizhao, Weihai, and Zaozhuang cities of Shandong Province, China. A total of 1,512 <i>Fusarium</i> isolates were obtained from collected samples and identified using sequence analysis of the translation elongation factor-1α (<i>TEF-1α</i>), RNA polymerase II largest subunit (<i>RPB1</i>), and RNA polymerase II second largest subunit (<i>RPB2</i>) gene sequences. Of these <i>Fusarium</i> isolates, 1,082 were identified as <i>Fusarium pseudograminearum</i>, and the remaining isolates were identified as <i>F. graminearum</i> (<i>n</i> = 338), <i>F. asiaticum</i> (<i>n</i> = 41), <i>F. proliferatum</i> (<i>n</i> = 17), <i>F. sinensis</i> (<i>n</i> = 8), <i>F. oxysporum</i> (<i>n</i> = 7), <i>F. acuminatum</i> (<i>n</i> = 6), <i>F. verticillioides</i> (<i>n</i> = 5), <i>F. nanum</i> (<i>n</i> = 3), <i>F. sulawesiense</i> (<i>n</i> = 2), <i>F. fujikuroi</i> (<i>n</i> = 1), <i>F. odoratissimum</i> (<i>n</i> = 1), and <i>F. reticulatum</i> (<i>n</i> = 1). Among the 13 <i>Fusarium</i> species, <i>F. verticillioides</i>, <i>F. nanum</i>, <i>F. sulawesiense</i>, <i>F. fujikuroi</i>, <i>F. odoratissimum</i>, and <i>F. reticulatum</i> were obtained from wheat FCR samples for the first time and were considered six new record species. Pathogenicity tests of all the six newly recorded <i>Fusarium</i> species on the major wheat cultivar 'Jimai 22' revealed that all the tested isolates caused FCR disease. This is the first report of <i>F. fujikuroi</i>, <i>F. nanum</i>, <i>F. odoratissimum</i>, <i>F. reticulatum</i>, <i>F. sulawesiense</i>, and <i>F. verticillioides</i> causing wheat FCR worldwide.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":"PDIS10242130RE"},"PeriodicalIF":4.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142896656","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":"Genetic Diversity of <i>Moniliophthora roreri</i> from Cacao Trees Growing in the Soconusco Area, Chiapas, Mexico.","authors":"Nadia Denisse Rodríguez-Velázquez, Sylvia P Fernández-Pavía, Daniela Pineda-Vaca, Juan-Daniel Tlacuilo-Cano, Guillermo López-Guillén, Belén Chávez-Ramírez, Paulina Estrada-de Los Santos","doi":"10.1094/PDIS-04-24-0873-RE","DOIUrl":"10.1094/PDIS-04-24-0873-RE","url":null,"abstract":"<p><p><i>Moniliophthora</i> <i>roreri</i> (Cif.) Evans et al. is the causal agent of frosty pod rot (cacao moniliasis). This disease represents the main phytosanitary problem that cacao production faces in Latin America. The vast destructive capacity of frosty pod rot leads to high economic losses. This study aimed to determine the genetic diversity of <i>M. roreri</i> associated with cacao trees growing around the Soconusco area in Chiapas, Mexico, through the inter simple sequence repeat analysis or ISSR. The study analyzed 145 strains of <i>M. roreri</i> isolated from 17 sites belonging to 12 regions in the Soconusco area, from Suchiate in the south, near the Guatemala border, to Acapetahua in the north of Chiapas. According to the results of the analysis, two genetic groups were identified: the first one was located in the north of the Soconusco area, and the second in the south. The analysis of molecular variance (AMOVA) indicated higher variability in the populations (59.64%) among sampling sites than within the populations (40.35%), and together with the Mantel analysis (<i>P</i> = 0.034), it indicated that the gene flow of <i>M. roreri</i> is affected by landscape features, such as mountains, roads, and rivers.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":"PDIS04240873RE"},"PeriodicalIF":4.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142896737","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 <i>Cophinforma tumefaciens</i> causing stem swelling, canker, and dieback of Tea plant (<i>Camellia sinensis</i>) in China.","authors":"Xiao-Han Liang, Hao-Hua Liu, Xiang Gao, Ming-Liang Yin","doi":"10.1094/PDIS-05-24-0966-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-05-24-0966-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The tea plants (&lt;i&gt;Camellia sinensis&lt;/i&gt;), one of the earliest cultivated woody crops with numerous varieties, have a rich history of cultivation in China. However, tea plantations (23°55'11″N, 116°42'4″E) in Chaozhou, Guangdong Province, a leading tea production and export region, face a severe disease outbreak. Approximately 50-60% of tea plants in this area exhibit stem swelling, canker, and eventual dieback symptoms. Ten diseased stem samples were collected from the affected plantations to investigate the causal agent. Isolation was carried out within three days of collection. Hyphae grown out from the xylem of the infected tissues were recovered and incubated on potato dextrose agar (PDA) plates for four weeks in the dark. A total of 53 isolates were obtained from diseased branches. The colonies were villous; initially, the colony's center was white, and the edge was olive. As it grew, dark pigmentation was produced, which caused the center to turn olive and the edge to turn greenish-black. When the sporulation in PDA media was absent, a piece of mycelial disk was picked from the colony's edge and inoculated on autoclaved custard apples (&lt;i&gt;Annona squamosa&lt;/i&gt;) (Cardoso et al. 2002). Pycnidia were observed over the surface of whole fruits after incubation for four weeks at 25°C. Conidiophores were olive-colored, unicellular, winding, and ellipsoid to obovoid, with rare spore production. Conidia were hyaline, ellipsoid to fusiform, 5.0 to 7.0 (avg. 6.3) μm in length and 1.8 to 2.5 (avg. 2.0) μm in width. No sexual structure was observed. DNA extraction was conducted from the hyphae grown on the PDA of five representative isolates using the PrepMan® Ultra Sample Preparation Reagent (Applied Biosystems, USA). The internal transcribed spacer (ITS) and translation elongation factor-1α (TEF-1α) regions were amplified using primers ITS5/ITS4 (White et al. 1990) and EF1-728F (Carbone and Kohn 1999) /EF-2 (O'Donnell et al. 1998), respectively. The PCR reaction was in a 25 μL mixture system, including 1 μL of DNA template, 0.5 μL of each primer (10 μM), 0.5 mL of Mytaq polymerase (Bioline, USA), 5 μL of MyTaq buffer, and 17.5 μL PCR grade water (Yin et al. 2020). PCR conditions were an initial denaturation step at 95°C for 3 min, followed by 35 cycles of 95°C for 30 s, 55-52°C for 30 s, and 72°C for 1 min, and a final elongation at 72°C for 10 min. The sequences obtained from this study were deposited in GenBank under the accession numbers OQ565301, OQ565302, OQ565303, OQ565304, OQ565305 (ITS), and OQ570636, OQ570637, OQ570638, OQ570639, OQ570640 (TEF-1α). The BLASTn results of ITS and TEF-1α sequences indicated that all isolates were 100% identical to &lt;i&gt;Cophinforma tumefaciens&lt;/i&gt; isolate IMI 76762 (accession no. MW810287 and MZ073950, respectively). The combined ITS and TEF-1α dataset of &lt;i&gt;Cophinforma&lt;/i&gt; and related genera obtained from Genbank was analyzed using the maximum likelihood method, applying the GTR+I+G model, with 1,000 bootstra","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302629","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}