Plant disease最新文献

{"title":"First Report of Goji Fruit Rot Caused by <i>Aspergillus terreus</i> in Ningxia, China.","authors":"Yueli Zhou, Wei Tian, Lunaike Zhao, Mangchen Li, Wenqing Zhang, Bin Sun, Huanhuan Li, Junjie Wang, Qiding Peng","doi":"10.1094/PDIS-01-25-0191-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-01-25-0191-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Goji berry (Lycium barbarum L.) is a fruit with high nutritional and medicinal value, widely cultivated in northwest China (Wang et al. 2023). In June 2022, unusual lesion symptoms were observed on goji berries harvested from an orchard located in Yinchuan, Ningxia, China (38.65°N, 106.16°E), and stored for 3 days at 25 ± 2 ℃ and 50 - 60% relative humidity (RH). Approximately 82.86% of the goji berries (n = 251) showed rot symptoms, initially characterized by white hyphae and water-soaked lesions, which later became light yellow. These symptoms were accompanied by water loss, tissue collapse, and a foul odor. To isolate the pathogen, six symptomatic tissue pieces (2 to 3 mm2 each) excised from the lesion margins of goji berries were surface-sterilized with 75% ethanol for 30 s, rinsed three times with sterile water, treated with 0.1% HgCl2 for 30 s, rinsed three more times with sterile distilled water, and finally dried on sterile filter paper. The sterilized tissues were then placed on potato dextrose agar (PDA) plates and incubated at 28℃ in the dark for 5 days. The growing hyphae were transferred to new PDA plates using the hyphal tip method (Türkkan et al. 2022). Their fungal mycelium initially appeared white, gradually turned tawny and eventually became dark brown on PDA. The conidia were spherical, unicellular, smooth, pale yellow, and measured 2.05 ± 0.19 μm (n = 33). All morphological characteristics were consistent with Aspergillus spp (Dania and Olaleye. 2022; Embaby et al. 2022). The internal transcribed spacer region (ITS) of the ribosomal DNA, cis-aconitic acid decarboxylase (Cad), and β-tubulin genes of three representative isolates (LNB-2301 to LNB-2303) were amplified by PCR and sequenced using primers ITS1/ITS4, Cad-F/Cad-R, and T1/T2, respectively (Bafana et al. 2017; Glass and Donaldson 1995). The sequencing results of the three isolates were deposited in GenBank (OR701874, PQ789218, and PQ789219 for ITS; OR701875, PQ827464, and PQ827465 for β-tubulin; OR701876, PQ827462, and PQ827463 for Cad, respectively). BLASTn analysis of the ITS, β-tubulin and Cad sequences showed 99.65 to 100% sequence similarity with Aspergillus terreus. The phylogenetic tree analysis displayed that these new isolates (LNB-2301 to LNB-2303) clustered in the same clade with A.terreus C1. Pathogenicity tests were conducted three times by inoculating healthy fruits (n = 10) with 2 µL of conidial suspension (1x106 conidia/mL) from a 5-day-old culture of LNB-2301. Sterile distilled water was used as the negative control. All the inoculated fruits were incubated at 25 ± 2 ℃, 50 to 60 % RH. Symptoms after inoculation were similar to those observed on naturally infected fruits, whereas the control fruits remained asymptomatic as expected. Furthermore, the diameter of the lesions was 10.6 mm, as measured using the cross-bonded method on the fifth day. The pathogen was subsequently reisolated from these infected fruits and confirmed to be A.terreus based on","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616778","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":"Morpho-molecular identification of <i>Colletotrichum scovillei</i> causing anthracnose disease of banana in Pakistan.","authors":"Muhammad Fahim Abbas, Sana Batool, Muhammad Bilawal Junaid, Najat A Bukhari, Ashraf Atef Hatamleh","doi":"10.1094/PDIS-09-24-1808-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-09-24-1808-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Banana (Musa spp.) is widely cultivated as the major fruit in Pakistan. Anthracnose fruit rot caused by various Colletotrichum spp. is a serious disease. Sample of 23 banana fruits were obtained from 4 commercial orchards (43% incidence) in Uthal, Balochistan, Pakistan. One or more small light-brown to reddish-brown spots were observed on all fruits during early stage of infection and later became sunken lesion. The pieces of diseased tissues were cut from margins, surface sterilized with sodium hypochlorite (0.3%), rinsed in sterile distilled water, dried on sterile filter papers and shifted on potato dextrose agar (PDA). Colony morphology of all isolates (n=21) on PDA were white fungal colonies which became dark gray after 7 days. Smooth, aseptate, cylindrical and hyaline conidia (n=20 per isolate) were recorded and measured 10.2 to 16.1 (avg. 12.3) × 3.7 to 4.5 (avg. 3.8) µm. Genomic DNA was extracted from a representative isolate LUAWMS and sequences from the internal transcribed spacer region (ITS), β-tubulin (TUB2), calmodulin (CAL), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), actin (ACT) and chitin synthase 1 (CHS-1) genes were amplified through polymerase chain reaction with the primer pairs ITS1/ITS4, BT1/BT2, CAL1/CAL2, GAPDH1/DAPDH2, ACTN1/ACTN2 and CHS1/CHS2, respectively. The sequences were exhibiting 100% genetic similarity with previously reported isolates SPTD26 (ITS, accession no PQ780054), PHL6, (TUB2, accession no KY475555), HNCS015 (CAL, accession no KX673577), Cer015 (GAPDH, accession no MK473911), QJ2_1 (ACT, accession no OQ613619) and CAUA43 (CHS-1, accession no KP145299) of Colletotrichum scovillei. ITS, TUB2, CAL, GAPDH, ACT and CHS-1 multi-locus sequences were deposited in GenBank under the accession numbers OK493385, OK493386, OK493387, OR449357, OR449358 and OR449359, respectively. For the confirmation of Koch's postulates, banana fruits (n=3) were surface sterilized with 70% ethanol, washed with sterile distilled water and wounded with the help of sterile needle. The spore suspension (1 × 106 conidia/mL) from LUAWMS were pipetted (10 µL) on wound fruit and incubated at 28°C with 12 h dark and light cycle. Moist paper towels was placed on bottom of a sealed crisper box and artificially inoculated fruits were shifted to a humid chamber. Three replicate boxes each contained one banana per treatment. Sterile distilled water was used as a negative control and the experiment was repeated once. After 7 days, small light-brown to reddish-brown spots (length averaged 14.9 mm, std. dev. = 4.0 mm) by 11.3 mm (std. dev. = 1.9 mm) were recorded on artificially inoculated fruits but not on control. Same pathogen was re-isolated from artificially inoculated fruit on PDA and morphological examination and molecular identified was used for the confirmation as previously described. Morphological characterization, molecular identification, multi-locus sequence analysis and Koch postulates confirmed LUAWMS as C. scovillei belo","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616779","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":"Identification of a Burkholderia species causing onion bulb rot disease.","authors":"Ram Neupane, Beth Gugino, Veronica Roman-Reyna","doi":"10.1094/PDIS-12-24-2675-SC","DOIUrl":"https://doi.org/10.1094/PDIS-12-24-2675-SC","url":null,"abstract":"<p><p>This short communication reports two bacterial strains (22PA0099 and 22PA0106) of a previously undescribed Burkholderia species causing bulb rot in onion. These strains were recovered from symptomatic onion plants collected from Pennsylvania (PA) during the routine scouting of onion fields in 2022. The strains were identified as Burkholderia sp. through 16S rRNA sequencing with the highest percentage of identity, coverage, and E-value of 98.7%, 98 to 100%, and zero respectively. In addition, primers targeting the recA gene were used to characterize species. Both strains had the closest hits with B. perseverans and B. gladioli, with 94 to 100% coverage and 92 to 95% identity in the recA gene. The whole genomes of both strains were sequenced using long-read sequencing. Comparisons with available genomes indicated that these strains had the closest identity with Burkholderia gladioli, with 92% average nucleotide identity. Furthermore, the two strains shared 97% sequence identity, suggesting they belong to the same species. These percentages indicate that the strains likely represent a novel Burkholderia species not reported previously on onion. A whole onion bulb assay confirmed the two strains pathogenicity. The proper identification and monitoring of this pathogen is important to help growers make informed decisions regarding disease diagnosis and management.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Xanthomonas citri</i> pv. <i>lagerstroemium</i>, description of a new pathovar causing leaf spot on crape myrtle.","authors":"Izabela Moura Duin, David F Ritchie, Evan Braswell, Jennie Ruth Fagen","doi":"10.1094/PDIS-09-24-2009-SC","DOIUrl":"https://doi.org/10.1094/PDIS-09-24-2009-SC","url":null,"abstract":"<p><p>Bacterial leaf spot caused by Xanthomonas was reported in 2014 as a new disease of crape myrtle. Unfortunately, this foundational strain was lost, preventing further experimentation, sequencing of the genome, and phylogenetic analysis. This work describes a collection of Xanthomonas strains isolated from angular leaf spot lesions on crape myrtle in North Carolina from 2014 to 2023. This study includes full reference genomes, as well as re-fulfillment of Koch's postulates. Genomes were obtained with hybrid whole genome sequencing using Illumina and Nanopore and assembled to develop robust genomic resources for these disease-causing strains. The completed genomes support inclusion of the strains in the X. citri species group; however, both phylogenetic analysis and the identification of a novel plant host suggest the creation of the new pathovar Xanthomonas citri pv. lagerstroemium.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606032","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":"PmAm, a broad-spectrum powdery mildew resistance source located on <i>Amblyopyrum muticum</i> chromosome 6T, is transferred to common wheat.","authors":"Wenjing Xu, Pengtao Ma, Huagang He, Zujun Yang, Ran Han, Xiaoyi Xu, Aifeng Liu, Xinyou Cao, Haosheng Li, Jianjun Liu, Takao Komatsuda, Cheng Liu","doi":"10.1094/PDIS-12-24-2594-RE","DOIUrl":"https://doi.org/10.1094/PDIS-12-24-2594-RE","url":null,"abstract":"<p><p>Powdery mildew (caused by Blumeria graminis f. sp. tritici) limits grain production and reduces grain quality in wheat. Amblyopyrum muticum (2n=2x=14, TT genomes), a wild relative of wheat, carries agronomically valuable traits, including resistance to powdery mildew, that have not been transferred to wheat. Here, a powdery mildew resistant Chinese Spring-Am. muticum amphiploid was backcrossed to a powdery mildew susceptible wheat cultivar and homozygous resistant derivatives with broad-spectrum resistance were selected. Fluorescence in situ hybridization analysis identified chromosome substitution and compensating Robertsonian translocation lines involving chromosome 6T from Am. muticum.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606102","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":"Resistance development to procymidone and boscalid in <i>Alternaria alternata</i> causing black spot disease on <i>Fritillaria thunbergii</i>.","authors":"Jiling Wang, Liyan Zhu, Chuan-Qing Zhang","doi":"10.1094/PDIS-12-24-2638-RE","DOIUrl":"https://doi.org/10.1094/PDIS-12-24-2638-RE","url":null,"abstract":"<p><p>Fritillaria thunbergii is a valuable medicinal plant threatened by black spot disease caused by Alternaria alternata for which application of fungicides is the primary strategy. However, the detection and characterization of fungicide resistance status in F. thunbergii has not yet been reported. A total of 106 and 128 single spore isolates of A. alternata were recovered in 2015 and 2021, respectively, from 52 and 56 F. thunbergii fields located in Jinhua, Wenzhou, Hangzhou, and Ningbo, where 90% of F. thunbergii is produced. In 2015, moderate resistance to procymidone (Pro^MR), a dicarboximide fungicide that has been applied for more than 10 years, was detected at a rate of 23.6%, and the resistance frequency increased to as high as 44.5% in 2021. For the SDHI boscalid, the EC₅₀ values ranged from 0.013 to 0.976 μg/mL, with the baseline EC₅₀ value of 0.57 ± 0.29 μg/mL in 2015, while the sensitivity profile showed prominent characteristics of a disruptive distribution, with a resistance frequency of 22.6% in 2022. Positive cross-resistance was observed between procymidone and iprodione (ρ = 0.897, P = 0.000), boscalid, and pydiflumetofen (ρ = 0.937, P = 0.000). No fitness penalty in growth, sporulation, germination, or pathogenicity was found for the Pro^MR or the boscalid-resistant (Bos^R) isolates. P894L of Os-1 was observed in all the tested Pro^MR isolates, and the double point mutation (P894L + S1277L) was detected in 33.3% of Pro^MR isolates. Four types of mutations in Sdh (G14W in Sdh B, V181G in Sdh D, A47T in Sdh D, and G14W in Sdh B + A47T in Sdh D) were found in the Bos^R isolates.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606106","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>Pseudomonas oryzihabitans</i> Causing Pith Necrosis on Pepper in Hainan Provinces, China.","authors":"Wuyi Xu, Meng Luo, Yingren Zhou, Jie Li, Chunhui Zhu, Jingyuan Zheng","doi":"10.1094/PDIS-10-24-2088-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-10-24-2088-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Peppers (Capsicum annuum L.) are among the most widely consumed vegetable globally and cultivated in large areas in China (Zhou and Zhou 2021). In December 2023, pepper pith necrosis was discovered in a field located in Haiwan Town, Haitang District, Sanya City, Hainan, China (109.69°N, 18.35°E), with an incidence of 15%. The lower leaves of diseased plants exhibited yellowing, and the stem epidermis degenerated, revealing aberrantly thickened and browning vascular tissue. Additionally, a small number of adventitious roots were observed on the stem. When main stems were longitudinally cut, a brown and disintegrated, partially hollow pith was observed. To isolate and identify the causal agent of pith necrosis in peppers, the border tissue between diseased and healthy areas was excised, sterilized by immersion in 70% ethanol for 1 minute, and then washed three times with sterile water. After drying, the treated tissues were cut into small pieces measuring 5 x 5 mm and cultured on Luria-Bertani agar (LB) medium. Following incubation at 28°C for 48 hours, isolation and purification of the bacteria obtained from the cultures were continued. After several purification, the colonies appeared yellow, circular, and smooth-margined. The cells obtained from colonies were negative for Gram staining and rod-shaped under the optical microscope. They were positive for catalase and urease but negative for oxidase and amylase, and were able to utilize L-arabinose, D-glucose and D-mannitol. Morphological, physiological and biochemical characteristics of the isolates resembled that of Pseudomonas sp.. To verify the species identity of the bacteria, genomic DNA from the isolated strain HN6 was extracted, and the universal primers 27F/1492R (Lane 1991) were used to amplify the 16S rRNA gene, while specific primers LAPS27/VIC4 (Mulet et al. 2010) and gyrBPF/gyrBPR (Yamamoto et al. 2000) were used to amplify the rpoB and gyrB genes. The BLASTn analysis of 16S rDNA, rpoB, and gyrB sequences showed strain HN6 (PQ374171, PQ393140, and PQ393141) had 100.00, 98.94% and 98.97% identity with P. oryzihabitans(CP044074). The phylogenetic analysis ( Mega 11 ) indicates that strain HN6 is clustered with P. oryzihabitans into one branch with Bootstrap supported 100 using the neighbor-joining method with 5,000 bootstrap replicates, further confirms that strain HN6 is most closely related to P. oryzihabitans. Therefore, strain HN6 was identified as P. oryzihabitans based on morphology, metabolic profile, and sequence analysis. Peppers were planted in non-porous pots containing sterilized substrates for the pathogenicity test. Sterile syringes were used to prick the stems near the roots of the peppers. The wounds were wrapped with sterile defatted cotton dipped in bacterial suspension ( 108 CFU / mL ). As a control, sterile defatted cotton soaked in sterile water was applied. Subsequently, the pots were covered with a plastic film to prevent contamination and moisturize. The te","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606038","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>Plectosphaerella pauciseptata</i> Associated with Tomato Root Rot Disease in China.","authors":"Zeshun Chen, Yunyun Chen, Yueyan Zhou, Pengzhao Chen, Wei Zhang, Mei Liu, Jiye Yan, Chenfang Wang","doi":"10.1094/PDIS-12-24-2652-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-12-24-2652-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Tomato (Solanum lycopersicum) is widely grown worldwide, ranking first among vegetable crops. Root diseases of tomatoes can cause serious yield losses. In June 2023 and 2024, tomato root rot symptoms were observed in the greenhouse with 70%-90% incidence approximate number of plants (N=210) in Beizhen City (121°47 ' 30 ''E, 41°35' 45 ''N), Liaoning Province, China. In 2024, the same symptoms were observed in the greenhouse in Shunyi City (116°39 ' 41 ''E, 40°09' 00 ''N), Beijing Province. Initially tomato leaves turned yellow, followed by wilting and withering of the entire plant. Roots and stems of the plants exhibited brown necrosis. Infected root tissues from six individual plants in each of two distinct regions were cut into 24 small fragments (5 × 5 mm) at the interface between healthy and symptomatic root tissue and surface sterilized with 2% NaOCl for 2 min followed by 75% ethanol for 30 s, rinsed five times with sterile water, and placed on potato dextrose agar (PDA). After 3-6 days of incubation at 25℃, hyphal tips from the edges of colonies were transferred to new PDA plates. Nine morphologically similar fungal isolates (JZB3540002-JZB3540010) were obtained from diseased samples. Six days old colonies on PDA were dense, mycelium appressed, white and the reverse was white to light yellow-brown. Conidiophores were straight or flexuous, unbranched, smooth, and had an elliptical apex. Conidia were elliptical, apex rounded, aseptate, and multi-guttulate. Conidia were 6 to 12 × 2 to 5 µm (average 7.70 × 2.95 µm, n=30). Following 14 days of incubation, colonies were hyaline with white mucilaginous masses, and aerial hyphae appeared at the center of the colony (Carlucci et al. 2012; Usami et al. 2012; Yang et al. 2021). For molecular phylogenetic analysis, genomic DNA was extracted from the nine isolates, and the internal transcribed spacer (ITS) region, large subunit 28S rDNA (LSU) and translation elongation factor 1 alpha (TEF-1alpha) gene were amplified using ITS1/ITS4 (White et al. 1990), LROR/LR5 (Vilgalys and Hester 1990), and EF-688F/EF-1251R (Alves et al. 2008) primers respectively. BLAST results indicated that the ITS, LSU, and TEF sequences showed 98 to 100% identity with Plectosphaerella pauciseptata type specimens sequences at NCBI (GenBank KY399823, KY662250, and KY421321). Maximum likelihood (ML) inference phylogenetic tree was constructed to confirm the identity of the nine strains. ML tree reveals that the nine strains clustered with Plectosphaerella pauciseptata with 100% bootstrap support value. Sequence data were deposited in NCBI GenBank with accession numbers PP716848 and PQ621101-PQ621108 (ITS), PP717077 and PQ621369-PQ621376 (LSU), and PQ629447-PQ629455 (TEF). To confirm pathogenicity, roots of 18 three-leaf-stage cultivar 'Ying fen 8' tomato seedlings were wounded and dipped in 50 ml conidial suspension (107 conidia/ml) or sterile water (control) for 30 min. Tomato seedlings were transplanted into new pots and plac","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606036","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":"Development of a tetraplex reverse transcription digital PCR (RT-dPCR) assay for three carlaviruses and an ilarvirus infecting hop and viral titer quantification in different tissue types.","authors":"Natalia Herrera-Blitman, Melody Bloch, Ericka Helmick, Scott Harper, Gary E Vallad, Brian W Bahder","doi":"10.1094/PDIS-11-24-2351-RE","DOIUrl":"https://doi.org/10.1094/PDIS-11-24-2351-RE","url":null,"abstract":"<p><p>The hop plant (Humulus lupulus) is an economically important perennial species of plant due to its role in beer production. While the majority of hop production occurs in central Washington State, local production in regions around the United States is gaining popularity due to local micro-breweries wanting to use locally grown hops in their production. In Florida, production has recently increased, and while most hop plants are grown from tissue culture, the development of a cost-effective diagnostic assay for hop viruses is critical to ensure planting material is clean. In this study, a tetraplex RT-dPCR assay was developed for the detection of four common hop viruses; Apple mosaic virus (ApMV), Hop mosaic virus (HMV), Hop latent virus (HLV) and American hop latent virus (AHLV). A synthetic control was generated with corresponding viral sequences inserted in tandem for optimization. Stem, petiole, and leaf tissue sampled from each of three different cultivars with different viral profiles were screened with the tetraplex RT-dPCR assay. Across all tissue types and cultivars, HLV had the highest titer level, followed by HMV and ApMV having the lowest levels. Additionally, there were significant levels of variation among tissue types across cultivars. These data highlight the utility of this assay for detecting viruses in hop tissue and provide a useful diagnostic tool for screening hop plants to confirm they are healthy. This assay will be utilized in vector studies but also integrated into diagnostic services.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597502","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 record of watermelon crinkle leaf-associated virus 2 infecting watermelon in open field in Italy.","authors":"Giuseppe Parrella","doi":"10.1094/PDIS-02-25-0245-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-02-25-0245-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Watermelon (Citrullus lanatus L.) is an important horticultural crop in Italy, with a production of around 600,000 tons per year (third producer in the Europe). Viruses are considered a limiting factor in watermelon production, especially those transmitted by efficient vectors such as whiteflies and aphids. In July 2023, foliar symptoms on 100% of watermelon plants (cv. Samba), including curling and wrinkling, yellow mottling and chlorosis, were observed in a commercial field of about 4000 m2 at Eboli (Salerno province, South Italy; coordinates: 40°29'83''N 14°57'99''E) (Figure S1). Some fruits were also symptomatic showing circular lesions and deformations. Overall, symptoms resembled those described for watermelon crinkle leaf-associated viruses (WCLaV-1, Coguvirus citrulli and WCLaV-2, Coguvirus henanense; genus Coguvirus, family Phenuiviridae) (Hernandez et al., 2021; Hendricks et al., 2022; Mulholland et al., 2023). Total RNAs were isolated from pooled leaf tissues of 10 symptomatic plants using the Viral Gene-spinTM Viral DNA/RNA Extraction Kit (iNtRON Biotechnology, Inc., South Korea) and used for construction of RNA-seq libraries, which were sequenced on an Illumina Novaseq 6000 platform with paired-end reads length of 101 bp. The HTS yielded 31,125,612 raw reads, while after trimming 28,868,089 reads were recovered. Viral genome assembly was performed with the two algorithms implemented in the SPAdes program (v. 3.15.3; Bankevich et al., 2012). Two sets of filtered contigs were obtained: 3,184 contigs with the algorithms implemented in Metaspades, and 3,369 contigs with algorithms implemented in RNAviral. BLASTn/BLASTx analysis of the contigs were carried out against online databases (https://blast.ncbi.nlm.nih.gov/Blast.cgi). Two contigs, obtained from the assembly of 7520 reads for RNA1 and 4585 reads for RNA2 respectively, showed the greatest nucleotide identities with the WCLaV-2 genome. These contigs represented full-length genomic sequences of the corresponding virus. No other viral contigs belonging to other viruses were generated by HTS library. The HTS results were confirmed by RT-PCR on each of the 10 watermelon samples using the WCLaV-2-specific primers WCLaV-2vRP (5'-GTCTCACATTCCTGCACTAACT)/WCLaV-2cRP (5'-ATCGGTCCTGGGTTATTTGTATC) targeting 968 bp of the RdRP and WCLaV-2vMP (5'-GACTTCAGAACCTCAACATCCA)/WCLaV-2cMP (5'-CAAGGGAGAGTGCTGACAAA) targeting 562 bp of the MP (Hernandez et al., 2021). Amplicons of the expected size were sequenced and sequences were 100% identical to the corresponding regions obtained by HTS sequencing, confirming presence of WCLaV-2 in the watermelon plants. After verifying the sequences at the 5' and 3' ends, the sequences of the two genomic ssRNA segments consisted of 6679 nucleotides (nt) for RNA1 and 2729 nt for RNA2. These sequences were deposited in GenBank with the accession numbers PQ869160 (RNA1) and PQ869161 (RNA2). According to the BLASTn analysis, the RNA1 was highly similar (99.94% sequ","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597526","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}