Plant disease最新文献

{"title":"Impact of DMI fungicides on <i>Bacillus subtilis</i> cell growth and consequences for disease control.","authors":"Johanna Wesche, Guido Schnabel","doi":"10.1094/PDIS-11-24-2367-RE","DOIUrl":"https://doi.org/10.1094/PDIS-11-24-2367-RE","url":null,"abstract":"<p><p>Strategic mixtures of biological control agents (BCA) with demethylation inhibitor (DMI) fungicides to control diseases of fruit crops can result in additive interaction, synergism, or antagonism. To evaluate the compatibility of eight commercial DMI fungicides with the BCA Bacillus subtilis AFS032321, marketed as Theia, bacteria were cultured in nutrient broth with 0, 10, 50, 100, and 150 µg/ml of each DMI fungicide at 30°C on a shaker rotating at 180 rpm and the optical density (OD600) was measured after 24 and 48 h. In addition, nutrient agar (NA) was enriched with the same concentrations and an endospore suspension was streaked out to count colony-forming units (CFU/ml) and measure the colony diameter. Results showed vegetative cell growth was strongly inhibited at > equal to 50 µg/ml difenoconazole and > equal to 100 µg/ml tebuconazole. All other DMI fungicides had little impact on B. subtilis AFS032321 cell growth at any concentrations tested. Interestingly, mefentrifluconazole significantly promoted colony growth (diameter) at all concentrations on NA. Theia applied at label rate combined with vegetative growth-promoting DMI fungicide mefentrifluconazole (formulated as Cevya) or vegetative growth-suppressing DMI fungicide difenoconazole (formulated as Inspire) at 150 µg/ml a.i. (active ingredient) were investigated against gray mold of cherry. Disease incidence and severity 5 days after inoculation indicated the best control efficacy and synergism (+10.2) for the mixture Theia + Cevya. For the mixture Theia + Inspire an antagonistic effect (-6.8) was calculated. Our results indicate that compatibility between biological and conventional fungicides must be considered if they are used in mixtures or together in integrated spray programs.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143399459","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":"Application of <i>Bacillus velezensis</i> 160 for the biocontrol of <i>Botrytis cinerea</i> in pomegranate.","authors":"Alberto Patricio-Hernandez, Andrés Quezada-Salinas Quezada-Salinas, Magnolia Moreno-Velázquez, Miguel Angel Anducho-Reyes, Yuridia Mercado-Flores","doi":"10.1094/PDIS-10-24-2118-RE","DOIUrl":"https://doi.org/10.1094/PDIS-10-24-2118-RE","url":null,"abstract":"<p><p>Botrytis cinerea is the causal agent of gray mold, a disease that attacks many plants worldwide. This phytosanitary problem was reported in orchards in the State of Mexico, Mexico, specifically in pomegranate crops. This study isolated this phytopathogen from fruits collected in the municipality of Chilcuautla, state of Hidalgo, Mexico, indicating that the disease is spreading across the country. Two strains of phytopathogens, MIC and MID, were obtained after conducting Koch's postulates. These strains were identified molecularly by amplifying and analyzing the concatenated sequence of the regions that correspond to the internal transcript spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (G3PDH), and DNA-dependent RNA polymerase subunit II (RPB2). In vitro confrontation tests demonstrated that B. velezensis 160 inhibited the development of both strains of B. cinerea under study through the action of nonvolatile thermostable and volatile metabolites. Applying this bacteria to pomegranate orchards for two consecutive years (2022, 2023) decreased the incidence, severity, and progression of the disease. We conclude that this bacterium can be used as a fungicide to control gray mold in pomegranate crops.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143399337","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 konjac mosaic virus infecting <i>Codonopsis pilosula</i> in China.","authors":"Kang Han, Yubao Zhang, Xuesi Su, Weijie Jin, Sailing Jing, Ruoyu Wang, Yang Qiu, Xia Zhao","doi":"10.1094/PDIS-05-24-1142-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-05-24-1142-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Radix Codonopsis pilosulae is a perennial herb of the genus Codonopsis, family Campanulaceae, and its dry root is frequently used in traditional Chinese medicine for hundreds of years for replenishing qi deficiency, strengthening the immune system, improving poor gastrointestinal function, decreasing blood pressure, etc. (He et al. 2015). However, there have been no previous reports of virus infection in C. pilosula. In July 2021 and July 2022, we collected 61 C. pilosula samples exhibiting virus symptoms of yellowing, mottling, and crinkling from fields in Gansu Province. A composite of six leaf samples was submitted to Biotech Bioengineering (Shangai) Co. Ltd. for small RNA sequencing. Total RNA of C. pilosula was extracted according to the manufacturer's directions using the total RNA extraction kit (Tiangen Biochemical Technology (Beijing) Co., Ltd.). The library was constructed using the TruSeq™ Small RNA Sample Prep Kits (Illumina, San Diego, USA), and was sequenced using the Illumina Hiseq 2000/2500 with a single-end read length of 1X50bp. Samples were sequenced to obtain 14349505 raw reads and 10081026 clean reads by removing low quality reads. Quality-controlled qualified reads were assembled using SPAdes (Bankevich et al., 2012) with a k-mer value of 17 and the obtained results were compared with NCBI's non-redundant nucleotide database. A contig of 8195 bp in length, with an 85% query coverage of the reference genome was annotated as homologous to konjac mosaic virus (KoMV, AB219545.1) with 80.60% nucleotide similarity. The virus-specific primers F 5`- ATAGCGGAAACGGCATT-3` and R 5`- GGCACGGCAGATAAACAC -3` were designed based on the contig to validate the sequencing results in individual samples. One of the original composite samples was KoMV positive. Polymerase chain reaction (PCR) products were resolved in 1.5% agarose gel and an ∼954 bp fragment was obtained (Fig. 1A). The PCR amplicons were submitted to Beijing Tsingke Biotech Co. Ltd. for Sanger sequencing. The obtained sequence (PP790593) was searched against the NCBI nucleotide database using the BLASTn algorithm. Results showed that it shared 98.85% nucleotide sequence identity with the genome of KoMV (MK770338). This is the first time that KoMV was found to naturally infect C. pilosula that was first identified in Amorphophallus Konjac in Japan(Shimoyama et al., 1992). KoMV belongs to the genus Potyvirus, family Potyviridae. To analyze the phylogenetic relationships of KoMV, partial coat protein (cp) genes of genus Potyvirus were downloaded from NCBI and a phylogenetic tree was constructed using the Neighbor-Joining method implemented in MEGA 11.0 software (Tamura et al. 2021) with default parameters. The KoMV isolate obtained from Gansu C. pilosula in this experiment clustered with KoMV sequences isolated from Angelica sinensis collected in China, which again proving that the virus is KoMV (Fig.1B). Additionally, a total 61 C. pilosula samples showing similar virus dise","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143399283","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 Canker of <i>Calocedrus decurrens</i> in Tennessee.","authors":"Pratima Subedi, Seyed Mohammad Rouhani, Jacob Shreckhise, Cansu Oksel, Farhat A Avin, Fulya Baysal-Gurel","doi":"10.1094/PDIS-10-24-2231-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-10-24-2231-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Incense cedar (&lt;i&gt;Calocedrus decurrens&lt;/i&gt;) is a conifer native to the western United States, valued for its low maintenance and aesthetic appeal in ornamental landscapes. In May 2024, field and container grown incense cedar exhibited canker and dieback in a USDA research plot at the Nursery Research Center, McMinnville, TN (Fig. 1a). Disease incidence was 60% of a total 100 plants. For isolation of the causal agent, small pieces (∼0.3 mm&lt;sup&gt;2&lt;/sup&gt;) of the branch and stem cankers were excised, surface sterilized with 1% sodium hypochlorite for 1 minute, followed by 70% ethanol for 30 seconds, and washed twice with sterile water. The pieces were placed on potato dextrose agar (PDA) and incubated at 25°C under 12-hour light/dark conditions. Colonies initially appeared white, and after four to six days, they gradually turned dark gray with dense aerial mycelia (Fig. 1b). Conidia produced within pycnidia after 3 weeks were hyaline, fusiform, and aseptate, with dimensions of 21.1 to 25.8 μm (avg. 24.35 ± 1.049 μm) in length and 5.7 to 8.2 μm (avg. 6.1 ± 0.687 μm) in width (&lt;i&gt;n&lt;/i&gt; = 50) (Fig. 1c). Pathogen identity was confirmed by extracting total genomic DNA using the DNeasy PowerLyzer Microbial Kit from 7-day-old pure cultures (isolates FBG7412 and FBG7413). The primer pairs ITS1/ITS4 (White et al. 1990), T1F/Bt2b (Glass and Donaldson 1995; O'Donnell and Cigelnik 1997), and EF1-728F/EF2 (Carbone and Kohn 1999) were used to amplify the ribosomal internal transcribed spacer (&lt;i&gt;ITS&lt;/i&gt;), and nuclear beta-tubulin (&lt;i&gt;TUB&lt;/i&gt;) and translation elongation factors 1-α (&lt;i&gt;EF1-α&lt;/i&gt;) genetic markers, respectively. The sequences of the two isolates (FBG7412 and FBG7413) were deposited in GenBank with accession numbers PQ482605 and PQ482606 (&lt;i&gt;ITS&lt;/i&gt;); PQ493369 and PQ493370 (&lt;i&gt;TUB&lt;/i&gt;); and PQ493366 and PQ493367 (&lt;i&gt;EF1-α&lt;/i&gt;), respectively. GenBank BLAST search of sequences using the core nt database showed 100% identity (100% coverage) of &lt;i&gt;ITS&lt;/i&gt;, &lt;i&gt;TUB&lt;/i&gt;, and &lt;i&gt;EF1-α&lt;/i&gt; sequences to &lt;i&gt;Botryosphaeria dothidea&lt;/i&gt; isolates IS2116-1 (OR958722), MEND-F-0379 (OQ994765), and IRNBS19 (MN633962), respectively. Phylogenetic analysis of concatenated &lt;i&gt;ITS&lt;/i&gt;, &lt;i&gt;TUB&lt;/i&gt;, and &lt;i&gt;EF1-α&lt;/i&gt; sequences confirmed the pathogen as &lt;i&gt;B. dothidea&lt;/i&gt; (Fig. 2). Two same two fungal isolates FBG7412 and FBG7413 were used to inoculate incense cedar cuttings grown in 3.8L pots with each plant measuring 12-15 cm in height. The inoculum was prepared by growing each isolate on PDA for one week at 25°C. For inoculation, a thin slice of bark (4 mm²) was removed from the stem of each cutting, and a 4-mm-diameter plug colonized by the fungal isolate was placed on the wound which was then covered with Parafilm. Negative controls were mock inoculated with sterile PDA plugs. There were five replications for each isolate and control. The study was conducted in a greenhouse maintained at 23-25°C and 70% relative humidity, with a 16-hour photoperiod. Six weeks post-ino","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143399371","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>Phytophthora ramorum</i> Causing Leaf Spot on <i>Arbutus × reyorum</i> 'Marina' in the United States.","authors":"Emma Marie Treadwell Deuitch, Suzanne Rooney-Latham, Cheryl L Blomquist, Wei Hao Belisle, Marinell C Soriano, Niklaus Grunwald","doi":"10.1094/PDIS-11-24-2379-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-11-24-2379-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The Marina strawberry tree (&lt;i&gt;Arbutus × reyorum&lt;/i&gt; Demoly. 'Marina') is a popular ornamental tree species, prized for its glossy evergreen foliage, display of pink and white bell-shaped blooms, and strawberry-like ornamental fruits. In April 2024, a foliar sample from a Humboldt County, California nursery, where &lt;i&gt;P. ramorum&lt;/i&gt; had been detected earlier in the year, was submitted to the CDFA Plant Pest Diagnostic Laboratory exhibiting symptoms of marginal leaf necrosis (Fig. S1). A limited number of symptomatic strawberry trees were located near infected &lt;i&gt;Cornus capitata&lt;/i&gt; plants. Six 6-mm-diameter disks were excised from the margins of diseased leaf tissues and cultured on semi-selective CMA-PARP media (Jeffers and Martin 1986). After approximately 7 days, white, coralloid, and coenocytic hyphae interspersed with globose chlamydospores (22.5 to 52.3 µm in diameter, n = 30), and ellipsoidal, semi-papillate sporangia (32.5 to 75 × 20 to 22.5 µm, n = 30) grew from the disks. This morphology is consistent with that reported for &lt;i&gt;P. ramorum&lt;/i&gt;. The pathogen was genetically identified by sequencing the internal transcribed spacer region (ITS) and cytochrome oxidase subunit 1 region (cox1) using the primers ITS5/ITS4 (White et al. 1990; accession no. PQ431562) and OomCox1Levup/Fm85mod (Robideau et al. 2011; accession no. PQ438384), respectively. A BLAST search of both amplicons revealed 100% identity with the &lt;i&gt;P. ramorum&lt;/i&gt; ex-type strain CPHST BL 55G (MG865581 and MH136973). Based on microsatellite loci, the isolate was placed within the NA2 clonal lineage (Goss et al. 2011). Koch's postulates were performed to confirm pathogenicity using 4-year-old &lt;i&gt;Arbutus × reyorum&lt;/i&gt; 'Marina' trees (58 to 75 cm tall) grown in 3.78-liter pots. The foliage of three plants was inoculated with 15 ml of a zoospore suspension of 1 × 104 zoospores/ml following the methods of Blomquist et al. (2021). Two control plants were sprayed with 15 ml of sterile water. All plants were placed in a dew chamber at 23°C. After three days, plants were moved to a growth chamber at 23±1°C with a 12-h photoperiod. During this time, black discoloration was noted on the youngest leaves of the inoculated plants. After approximately 7 days, symptoms characteristic of &lt;i&gt;Phytophthora&lt;/i&gt; infection were observed including drooping leaves, dieback, and dark foliar lesions extending from the petiole along the midrib into the leaf. By 13 days, the discoloration extended into the flower panicles (Fig. S2). These symptoms differed from those in the original nursery samples, which only displayed lesions along the leaf margins. Both the marginal necrosis in the submitted samples and the symptoms from the pathogenicity tests are consistent with ramorum leaf blight on many hosts under varying environmental conditions. &lt;i&gt;P. ramorum&lt;/i&gt; was consistently isolated from symptomatic foliage of the inoculated plants, while no symptoms were observed in the control group and no &lt;i&gt;Phytoph","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143383123","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>Colletotrichum truncatum</i> Causing Anthracnose on Melon (<i>Cucumis melo</i> L.) in China.","authors":"Yunfeng Ye, Chan Juan Du, Huayun Xie, Di Yang, Guifen Li, Shangbo Jiang, Sihua Qin, Rixin Hong, Yi He, Tangjing Liu, Jin Yan Huang, Gang Fu","doi":"10.1094/PDIS-11-24-2432-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-11-24-2432-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Melon (Cucumis melo L.) is an important economic crop in China, with a planting area of about 500,000 hectares, ranking first in the world. In May 2024, anthracnose symptoms were found on melon plants, particularly severe on the mature fruits, in Binyang County, Guangxi, China. Disease incidence was between 30% to 60% in four surveyed planting areas. The symptoms on fruits initially appeared as water-soaked lesions, gradually turning into dark brown sunken lesions, sometimes with cracks. Additionally brown necrotic lesions with yellowish edges appeared on the leaves. For pathogen isolation, lesion edge tissues (3×3 mm) of fruits were surface-sterilized in 75% ethanol (30 s) and 1% sodium hypochlorite (1 min), rinsed in sterile distilled water, and plated on potato dextrose agar (PDA) amended with streptomycin sulphate (30 mg/l) for 4 days at 28°C in the dark. Ten pure isolates with similar morphology were obtained by transferring hyphal tips to new PDA plates. Colonies were round with smooth margins. Mycelium was sparse, initially pale gray, then changed to dark gray with numerous black microsclerotia after 14 days and generated a small amount of orange conidial masses afer 30 days of cultivation. Conidia were single-celled, hyaline, slightly curved, tapered tip and truncate base, with an oil globule at center, and 18.9 to 22.2 × 3.2 to 4.7 μm (n = 50). Setae initiated from an acervuli, were dark brown, septate, straight, pointed, and measuring 85.5 to 146.3 × 4.2 to 5.5 μm. Appressoria were light brown, elliptic to claviform or slightly lobed. Morphological characters were similar to Colletotrichum truncatum (Damm et al. 2009). Two representative isolates M1 and M3 were used for molecular identification. The partial internal transcribed spacer (ITS) region, actin (ACT), β-tubulin (TUB2), chitin synthase (CHS-1), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were amplified with ITS1/ITS4, ACT512F/ACT783R, BT2A/BT2B, CHS-79F/CHS-345R, and GDF1/GDR1 primers, respectively. Sequences were deposited in GenBank (ITS: PQ549938, PQ549939; Actin: PQ562860, PQ562861; TUB2: PQ562866, PQ562867; CHS-1: PQ562862, PQ562863; GAPDH: PQ562864, PQ562865) and showed 97% to 100% similarity with C. truncatum strains. A maximum likelihood phylogenetic tree based on the concatenated these five loci in MEGA-X showed the clustering of the isolates M1 and M3 in the C. truncatum clade. Pathogenicity tests were performed twice in a greenhouse at 25 to 30°C with 90% relative humidity. The healthy living fruits were slightly wounded by sterilized needle. Then spore suspension (106 conidia/ml) of isolates M1 and M3 were inoculated onto the wounds (10 μl/wound). For each isolate, five fruits were inoculated. Control fruits were treated with sterile water. After 7 days, all the inoculated fruits showed brown lesions resembling natural symptoms, whereas no symptoms appeared on the negative controls. The same fungus was re-isolated from the symptomatic fruits, th","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143383117","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 Rhynchosia yellow mosaic virus (RhYMV) infecting butterfly pea (<i>Clitoria ternatea</i>) in India.","authors":"Subham Dutta, Souvik Chhandogi, Mritunjoy Barman, Swati Chakraborty, Tarique Ahmed, Poorvasandhya R, Jayanta Tarafdar","doi":"10.1094/PDIS-10-24-2175-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-10-24-2175-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Butterfly pea (Clitoria ternatea), also known as Asian pigeonwings is a perennial herbaceous plant belongs to the Fabaceae family has a great source of natural food colorants and antioxidants (Suarna et al., 2021). It is a multipurpose forage that produces bioactive compounds, acts as a cover crop and improves soil fertility through nitrogen fixation (Gomez et al, 2003). Rhynchosia Yellow Mosaic Virus (RhYMV) which is transmitted by the whitefly (Bemisia tabaci) was first reported from Pakistan in leguminous weed least snoutbean, Rhynchosia minima (Illias et al., 2009). There is no record on the infection of RhYMV in butterfly pea in India or anywhere in the world. In 2022 and 2023, 250 whole butterfly pea plants were collected from few home stead gardens from ten districts (Alipurduar, Darjeeling, Jalpaiguri, Cooch Behar, Malda, Nadia, Birbhum, Hoogly, Purulia and East Midnapore) within the West Bengal province in India, showed extensive yellow mosaic symptoms and distorted flower with bleaching of blue color of petals (Supplementary file 1). The detection of the virus was carried out in the Advanced Plant Virus Diagnostic Centre, Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India. DNA extraction was conducted by using plant genomic DNA isolation kit (Sigma-Aldrich, St Louis, USA). The concentration and purity of DNA samples were determined by DeNovix-DS11 spectrophotometer. The presence of the virus was confirmed through polymerase chain reaction (PCR) using begomovirus-specific degenerated primer (Li et al., 2004) followed by RhYMV specific primer (Ilyas et al., 2009). Out of total 250 test samples, 241 were positive for begomovirus specific degenerated primer (96.40%) and out of 241 positive samples, 178 plants were positive to RhYMV specific primer which confirmed 73.85% samples infected to RhYMV. After confirmation of the virus whole genome obtained through Rolling Circle Amplification (RCA) (TempliPhi 100 Amplification Kit, Cytiva) followed by sequencing. After assembled and analyzing the data in CLC Genomics version Workbench 21.0.5 (Matvienko, 2015) whole genome of DNA-A sequence was depositd in the NCBI GenBank database (accession number- PP735226). The BLASTn analyses of the sequence indicated that the isolate from West Bengal, had the 95.44% identity (2616 bp out of 2741 bp) with a RhYMV isolate from snoutbean (Rhyncosia minima) from Pakistan (FM208847). For pathogenecity test (Supplementary file 2), whiteflies reared under polyhouse conditions, acquired the virus from infected plants over 24 hrs (AAP) then allowed viruliferous whiteflies to inoculate the healthy plants for 24 hrs (IAP) and symptoms were monitored under an insect-proof cage. Around two weeks of post- inoculation, all Clitoria plants exhibited mild yellow mosaic symptoms. At 28 dpi, bright yellow to green mosaic appearance, downward curling, and wrinkling of the leaves accompanied with thin tendril with severely distorted flowers were seen which was similar","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143383171","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 Postharvest Fruit Rot Caused by <i>Aspergillus ochraceus</i> on Blue Honeysuckle (<i>Lonicera caerulea</i> L.) Fruit in China.","authors":"Haohao Yan, Yuxuan Li, Zijian Man, Yusheng Lv, Xin Zhao, Zexu Chen, Liangchuan Guo, Junwei Huo, Mingyu Sang, Chunyan Li, Yi Cheng, Hailian Zang","doi":"10.1094/PDIS-12-24-2557-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-12-24-2557-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Blue honeysuckle (Lonicera caerulea L.) plants produce small fruit that are used as food and medicine. In September 2024, 100 kg of blue honeysuckle 'Lanjingling' (China National Plant Variety Protection (CNPVP) 20200389) fruits were harvested in Harbin, China (126.48°E, 45.87°N), and 20% of the fruits showed postharvest fruit rot symptoms, leading to whole-fruit rotting with skin browning and necrotic lesions (Fig. 1. A). Small (1 to 2 mm) samples of infected tissue were obtained from five randomly selected fruits. Samples were surface sterilized with 75% ethanol for 30 s and 5% sodium hypochlorite (NaClO) for 3 min, rinsed three times with sterile distilled water, dried with paper towel, and plated on 9 cm Petri dishes containing potato dextrose agar (PDA). Purified cultures were obtained using the single-spore technique. After 5 d at 28°C, the colonies displayed yellow brown aerial mycelium on the PDA plates (Fig. 1. B, C). Conidiophores were transparent and smooth, while conidial heads were brown and nearly spherical (Fig. 1. D). The entire surface was fertile, producing mostly spherical to subglobose conidia with diameters of 2.12 to 3.24 μm (n = 50) (Fig. 1. E). The internal transcribed spacer region (ITS, included ITS1+5.8S +ITS2, GenBank PQ606583), β-tubulin (TUB, GenBank PQ611757), and nuclear large subunit rRNA (LSU, GenBank PQ620103) genes were partially amplified with their respective primers (ITS1/ITS4 (White et al. 1990), Btub2Fd/Btub4Rd (Glass and Donaldson, 1995) and LROR/LR7 (Rehner and Samuels, 1994). BLAST analysis revealed that the sequences of the three genes showed 99.30 to 100% homology (526/526 nt, 141/142 nt, and 882/882 nt) with the MH859926, AY819971, and MH876373 sequences for isolates of Aspergillus ochraceus. In a phylogenetic tree constructed by Maximum likelihood method based on ITS and TUB sequences, the isolate LDGS-6 was located in the same clade with A. ochraceus (Fig. 2). For pathogenicity, twenty healthy blue honeysuckle 'Lanjingling' fruits were superficially sterilized with 75% ethanol and washed with distilled water. Ten fruits were inoculated with a 10 μL conidial suspension of isolate LDGS-6 (106 spores/mL) and ten with sterile distilled water (control). After fruits were incubated in 9 cm Petri dishes at 28°C and 75% relative humidity in the dark for 7 d, inoculated fruits displayed rot symptoms while control fruits did not (Fig. 1. F and G). The experiment was replicated three times. The causal agent was isolated from inoculated fruits, and it was identified as the original isolate based on morphological traits and ITS, TUB, and LSU sequencing, whereas no Aspergillus-like strains were isolated from control fruits, thus confirming Koch's postulates. In conclusion, based on molecular, morphological, and pathogenic analysis, A. ochraceus is the causal agent of the fruit rot disease on blue honeysuckle fruits (Ou et al. 2024). A. ochraceus was previously reported in China in Shengzhou nane (on Prunus","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143383127","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":"Host Resistance Screening of Baby Kale Against Downy Mildew Isolates Across the Central Coast of California.","authors":"Emily Mae Locke-Paddon, Marco Antonio Fernandez, Kallol Das, Kyle Brasier, Charlie Dowling, Shunping Ding","doi":"10.1094/PDIS-11-24-2290-RE","DOIUrl":"https://doi.org/10.1094/PDIS-11-24-2290-RE","url":null,"abstract":"<p><p>Hyaloperonospora brassicae, the causal pathogen of downy mildew, presents significant challenges to spring mix greens production in California. Genetic resistance provides a strategy for sustainable management to reduce downy mildew infections and pesticide use in organic and conventional production systems. This study aimed to identify sources of downy mildew resistance to facilitate resistance breeding in baby kale. To achieve this, three host resistance screenings were conducted to assess the resistance of baby kale accessions against eight downy mildew isolates collected from eight distinct locations on the Central Coast of California. Artificial inoculation was performed by spraying a sporangia suspension onto baby kale plants, which were then incubated in a humidity chamber. Disease severity was assessed by examining both surfaces of each leaf for chlorotic and necrotic symptoms and sporulation and then quantified using an established rating scale. Screening of all 212 accessions revealed an average disease severity of 28%, with severities ranging from 0 to 100%. The initial subset screening showed average disease severities ranging from 2.2 to 9.4% depending on the isolate. The final subset screening demonstrated a range of 0.003 to 0.072% average disease severity among the four isolates, with 13 accessions exhibiting 100% estimated resistance probability, 11 accessions between 99.0 and 99.9%, and one accession below 99.0%. These results suggested that downy mildew could be effectively managed in baby kale through resistant varieties.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374528","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":"Mycotoxin contamination of hazelnut grown in Azerbaijan and <i>Aspergillus</i> communities associated with the crop.","authors":"Fagan Aghayev, Ranajit Bandyopadhyay, Paola Battilani, Alejandro Ortega-Beltran","doi":"10.1094/PDIS-12-24-2623-SC","DOIUrl":"https://doi.org/10.1094/PDIS-12-24-2623-SC","url":null,"abstract":"<p><p>In Azerbaijan, hazelnut (<i>Corylus avellana</i> L.) is a crop of economical and nutritional importance. However, recent aflatoxin contamination events in hazelnut produced in Azerbaijan are posing health risks to consumers and reduce marketability. Aflatoxin and fumonisin levels were examined in hazelnuts collected at 33 farmers' stores, one month after the 2022 harvest under various storage conditions, from two regions in Azerbaijan. All hazelnut samples were contaminated both with aflatoxins (range = 1.1 to 7.2 µg/kg) and fumonisins (range = 0.12 to 0.30 mg/kg). <i>Aspergillus</i> section Flavi fungi were isolated and both aflatoxin producers and atoxigenic (incapable of producing aflatoxins) isolates were identified. Several members of vegetative compatibility group IT006, to which the Italian aflatoxin biocontrol isolate MUCL54911 belongs, were found to be native to Azerbaijan. In laboratory competition assays, MUCL54911 reduced aflatoxin produced by three types of <i>Aspergillus</i> fungi by 97.5 to 100%, which indicates that biocontrol could be an option to reduce aflatoxin in hazelnut. Future research efforts should be geared toward detecting and characterizing additional atoxigenic isolates, optimizing biocontrol application for hazelnut, and implementing agronomic and post-harvest practices to manage aflatoxin throughout the value chain. For effective implementation of integrated mycotoxin strategies, coalitions composed of farmers, research institutions, non-governmental organizations, private sector, and government agencies are needed.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374529","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}