Plant disease最新文献

{"title":"Rapid population flux in bacterial spot xanthomonads during a transition in dominance between two genotypes in consecutive tomato production seasons and identification of a new species <i>Xanthomonas oklahomensis</i> sp. nov.","authors":"Brett Johnson, Aastha Subedi, John Damicone, Erica Goss, Jeffrey B Jones, Mustafa Ojonuba Jibrin","doi":"10.1094/PDIS-04-25-0734-SR","DOIUrl":"https://doi.org/10.1094/PDIS-04-25-0734-SR","url":null,"abstract":"<p><p>In the bacterial spot of tomato disease complex, Xanthomonas euvesicatoria pv. perforans (Xep) is known to outcompete X. euvesicatoria pv. euvesicatoria (Xee). The result, over time in tomato production systems where both pathogens are present, is the anticipated displacement of Xee by Xep. In this study, we characterized the population of recovered strains from grower fields in response to a bacterial spot of tomato outbreak in east and central Oklahoma in 2018 and 2019. Tomato and pepper strains sampled in earlier years were included to provide additional context. Phenotypic and genome-based analyses showed marked differences in race and species composition in recovered strains. All pre-2018 (2001-2014) tomato bacterial spot strains were Xep race T3, except one T4 strain. Tomato bacterial spot strains in 2018 consisted of Xee race T1 and Xep T3, while strains recovered in 2019 from the same locations were exclusively Xep T4 strains. The 2019 Xep T4 strains form the same cluster with the 2014 Xep T4 strain on the phylogenetic tree, suggesting the same population. Only the Xep race T4 strains did not elicit a hypersensitive reaction on pepper. The recovered strains were also variable in copper sensitivity and effector content. We additionally recovered non-bacterial spot xanthomonads, one of which belongs to the new species, Xanthomonas oklahomensis sp. nov. These results contribute to novel insights in understanding genomic heterogeneity and seasonal population flux between competing bacterial genotypes during disease outbreaks and can be considered when developing disease management strategies.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144964910","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":"Management of blossom blight in nectarine and peach with <i>Bacillus subtilis</i>.","authors":"Johanna Wesche, Guido Schnabel","doi":"10.1094/PDIS-06-25-1318-SC","DOIUrl":"10.1094/PDIS-06-25-1318-SC","url":null,"abstract":"<p><p>Monilinia fructicola, the causal agent of blossom blight and brown rot in peaches and nectarines, is currently managed with chemical fungicide programs in the Southeastern United States. However, increasing fungicide resistance and regulatory pressure to reduce synthetic fungicide use highlight the need for alternative strategies. This two-year field study evaluated the efficacy of the biologicals Bacillus subtilis AFS032321 formulated as Theia and Pseudomonas chlororaphis AFS009 formulated as Howler EVO alone and in combination, for blossom blight control in nectarines at the Musser Fruit Research Center in Seneca, SC. In addition, Theia was compared to the commercial standards at three different farms in five cultivars. Theia significantly reduced blossom blight in both years with an observed control efficacy of 79.2% in 2025 and 57.3% in 2024 and was statistically equivalent to the control efficacy of 64.9% for synthetic fungicide propiconazole (Propi-Star EC) in 2025. In contrast, Howler EVO had no significant effect on disease reduction. Notably, the combination of the two biologicals in field trials at the experiment station resulted in antagonistic interactions. On nutrient agar, B. subtilis AFS032321 colony formation was inhibited by Howler EVO even at 1/10 of the label rate, supporting the field observation of antagonism between the two biologicals. No significant differences were found between Theia and the commercial standard programs for blossom blight control in commercial farm field trials. These findings demonstrate the potential but also highlight the vulnerability of biological use for blossom blight management in nectarines and peaches.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144874611","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":"Screening <i>Prunus</i> genotypes with wild plum and almond parentage for resistance to Armillaria root disease.","authors":"Paula Eschen, Micah Stevens, Miriam Espinoza, Kendra Baumgartner","doi":"10.1094/PDIS-03-25-0666-RE","DOIUrl":"10.1094/PDIS-03-25-0666-RE","url":null,"abstract":"<p><p><i>Armillaria mellea</i> is the most virulent causal species of Armillaria root disease in California. Rootstocks widely planted in almond orchards, namely peach genotypes (e.g., 'Lovell'), are highly susceptible. Here we report on resistance of newly screened, diverse genotypes: plum hybrids '14-4', 'Magnus', and 'Rootpac R', complex hybrid 'Viking', and peach × almond hybrid 'SG 1'. The assay involved rooting clonal genotypes in semi-solid media, inoculating media with <i>A. mellea</i>, and assessing phenotypic traits (plant mortality, canopy necrosis, stem necrosis) weekly for 8 weeks. Effects of assay conditions on traits of non-inoculated plants were also monitored. A precise propagation schedule accommodated inoculations on different dates. Included were <i>Armillaria</i>-resistant controls 'Krymsk 86' and 'MP-29' (plum hybrids), susceptible control 'Lovell' (peach), and previously screened 'Hansen 536' (peach × almond hybrid) and 'Marianna 2624' (plum hybrid). Genotypes were compared at inflection points in trait development and when controls were significantly different (canopy and stem necroses at week 4, mortality at week 7). Based on consistent patterns among traits of inoculated plants, most resistant were '14-4', 'Hansen 536', 'Magnus', and 'SG 1' (statistically similar to 'Krymsk 86' and 'MP 29'). 'Rootpac R' and 'Viking' were most susceptible (statistically similar to 'Lovell'). However, high mortality, and canopy and stem necroses, of non-inoculated plants of 'Lovell', 'Rootpac R', and 'Viking' suggest these rootstocks were intolerant of the assay. 'Magnus', 'Marianna 2624', and 'SG 1' were statistically similar to resistant and/or susceptible controls, depending on the trait. Ongoing field trials will further evaluate performance of the rootstock genotypes.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144874612","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":"Transferring the <i>Psathyrostachys huashanica</i> 5Ns chromosome into wheat genetic background to enhance powdery mildew resistance.","authors":"Jiachuang Li, Jiaojiao Li, Qing Guo, Yuhui Pang, Chunping Wang, Zujun Yang, Wanquan Ji, Ji Xin Zhao","doi":"10.1094/PDIS-04-25-0895-RE","DOIUrl":"10.1094/PDIS-04-25-0895-RE","url":null,"abstract":"<p><p>Disease resistance is crucial for minimizing agricultural inputs and safeguarding food supply to solve world hunger. The genetic diversity of wild relatives provides a valuable resource for enhancing the disease resistance and yield of crops such as common wheat (Triticum eastivum). Psathyrostachys huashanica (2n = 2x = 14, NsNs) is a valuable wild germplasm for wheat improvement because of its resistance to various diseases and abiotic stresses. Here we report that WPh13-2, a wheat-P. huashanica distant hybridization progeny, exhibited exceptional resistance to wheat powdery mildew (PM) at both seedling and adult stages. Genome in situ hybridization (GISH) revealed a karyotype of 2n = 42 = 21 II in WPh13-2 that carries one pair of alien chromosomes from P. huashanica. Preliminary evidence from fluorescence in situ hybridization (FISH) and molecular markers analysis indicated that P. huashanica 5Ns chromosome substituted the wheat 5D chromosome in WPh13-2. The SNP array analysis demonstrated that the genotypes of most loci on the 5D chromosome of WPh13-2 were the same as in P. huashanica, but different from those of the wheat parent, confirming the replacement of the 5D chromosome with the 5Ns chromosome in WPh13-2. Analysis of PM resistance in the F2 population (MX169 × WPh13-2) located the PM resistance gene(s) on 5Ns chromosome. Finally, a 5Ns chromosome specific kompetitive allele-specific (KASP) marker was developed for molecular assistant selection of 5Ns chromosome. WPh13-2 will be a promising bridging germplasm for introgression of the PM resistance gene(s) into wheat breeding programs.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144874631","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":"Hybrid grapevine resistance to downy and powdery mildews in Israel under warm Middle Eastern conditions.","authors":"Tamir Zonenberg, Tirtza Zahavi, Ofir Degani, Michael Striem, Meir Shlisel, Mery Dafny Yelin","doi":"10.1094/PDIS-06-25-1151-RE","DOIUrl":"10.1094/PDIS-06-25-1151-RE","url":null,"abstract":"<p><p>Vitis vinifera grapevines are susceptible to downy and powdery mildews, requiring 4-10 chemical treatments per season in Israel. Resistant grape varieties offer an alternative. Hybrid varieties developed by the Weinbauinstitut Freiburg were introduced in Israel for disease resistance evaluation in different climatic regions through an understanding of the resistance mechanism based on secondary metabolite profiles. Grapevines were planted across four different climatic regions in northern Israel. Key findings: (i) in the laboratory, after artificial inoculation of downy mildew, the susceptible V. vinifera variety Cabernet Sauvignon had six time more Plasmopara viticola sporangia per leaf disc than the hybrids varieties (p < 0.001). For powdery mildew, the susceptible variety had Ca. 3x104 more spores/cm² leaf area, than the hybrids varieties; (ii) in four tested vineyards, located in different climatic zones, downy mildew was only observed on the V. vinifera varieties; up to 4.6 times more powdery mildew incidence was observed on susceptible V. vinifera references more than on hybrid variety Cabernet Carbon , hybrid varieties Bronner and Prior were only infected with powdery mildew on clusters, up to 33.6 times less than the reference. Souvignier Gris showed no infection in 4 plots over 3 years; (iii) hybrid red grapevine varieties Prior and Cabernet Carbon showed significantly higher levels of antifungal response mediators, such as salicylic acid, than red V. vinifera variety Tempranillo. These elevated metabolite levels correlated with increased resistance to downy and powdery mildews in the hybrids. This study advances our understanding of tolerance mechanisms in hybrid grape varieties and highlights their potential adaptation to Israel's climate in different terroir conditions.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144874610","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":"Assessment of leaf spot disease-resistant hydrangea cultivars and the role of epidermal wax underlying in their resistance to leaf spot disease.","authors":"Huijie Chen, Jundan Mao, Xintong Liu, Xiangyu Qi, Shuangshuang Chen, Jing Feng, Yan Dong, Yanming Deng","doi":"10.1094/PDIS-04-25-0741-RE","DOIUrl":"10.1094/PDIS-04-25-0741-RE","url":null,"abstract":"<p><p>Hydrangea (<i>Hydrangea macrophylla</i>), a globally significant ornamental species, suffers severe economic losses from leaf spot disease caused by <i>Corynespora cassiicola</i>. Through detached-leaf assays screening 40 commercial cultivars, this study identified seven resistant cultivars ('Rivet', 'White Angel', 'Blue Danube', 'Flora', 'Fire Works', 'Spring Bird', and 'Inspiration') with distinct phenotypic clustering. Comparative analysis of resistant 'White Angel' (WA) versus susceptible 'Ocean Heart' (OH) revealed multilayered resistance mechanisms: WA exhibited 19.33% thicker leaves and significantly smoother epidermis (<i>P</i> < 0.05), alongside 3.11-fold higher leaf wax content dominated by C28-C32 fatty acids, primary alcohols, and alkanes. Scanning electron microscopy at 24 h post-inoculation (HPI) demonstrated WA's structural defenses via significantly lower hyphal colonization and smaller stomatal apertures. Transcriptomic profiling identified six cuticular wax biosynthesis genes upregulated in OH at 24 HPI, whereas WA prioritized constitutive defenses with only two induced wax transporter genes (TRINITY_DN9458_c1_g1 and TRINITY_DN1615_c0_g1). These findings provide insights into the role of leaf tissue epidermal waxes in the hydrangea resistance to leaf spot disease, laying a foundation for understanding disease resistance mechanisms and breeding for disease-resistant hydrangea cultivars.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144874609","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":"Georgia blueberry <i>Neopestalotiopsis</i> isolates, which are phylogenetically indistinguishable from the emerging novel strawberry <i>Neopestalotiopsis</i> sp., are pathogenic to both blueberry and strawberry.","authors":"Mirza Ashikul Beg, Jonathan E Oliver","doi":"10.1094/PDIS-04-25-0901-SC","DOIUrl":"https://doi.org/10.1094/PDIS-04-25-0901-SC","url":null,"abstract":"<p><p>A novel <i>Neopestalotiopsis</i> sp. causing an emerging crown, leaf, and fruit disease on strawberry has been associated with significant losses in recent years in the Eastern U.S and Canada. Particularly aggressive on strawberry relative to other <i>Neopestalotiopsis</i> spp., isolates of this novel species are morphologically similar to the relatively less aggressive species <i>Neopestalotiopsis rosae</i> and have been genetically differentiated from <i>N. rosae</i> based on multilocus sequence analysis as well as restriction fragment length polymorphisms (RFLP) within the fungal beta-tubulin gene. Here, from blueberry fruit collected from commercial blueberry production sites in southern Georgia (U.S.A.), we report the isolation, identification, and characterization of <i>Neopestalotiopsis</i> isolates which are phylogenetically indistinguishable from the novel <i>Neopestalotiopsis</i> sp. from strawberry. Isolates collected from blueberry across multiple growing seasons were identified as belonging to the novel <i>Neopestalotiopsis</i> sp. based on RFLP and multilocus sequence analysis. Moreover, these isolates were found to be capable of causing disease on both blueberry and strawberry plants in greenhouse experiments. These findings expand our understanding of this novel <i>Neopestalotiopsis</i> sp. and have implications for the diagnosis and management of <i>Neopestalotiopsis</i> diseases on small fruit crops.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144822248","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>Clonostachys rosea</i> Causing Root Rot of <i>Lonicera japonica</i> Thunb. in China.","authors":"Yanxin Li, Xin Liu, Chunyan Ding, Lu Rui, Rujie Shi","doi":"10.1094/PDIS-04-25-0749-PDN","DOIUrl":"https://doi.org/10.1094/PDIS-04-25-0749-PDN","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Lonicera japonica Thunb., belonging to Caprifoliaceae, is a widely cultivated traditional Chinese medicinal plant with high economic value. In May of 2024, symptoms of a root rot disease were observed on L. japonica in commercial plantings in Longju Town, Baitu Town, and Gaoliang Town in Wanzhou District (30°23'50″N, 107°52'22″E), Chongqing City (southwestern China). Aboveground parts of infected plants were entirely necrotic and displayed weakened lignification of roots with incidence rate of 45 to 70%. To identify the pathogen, root tissues from 17 diseased plants were collected, surface disinfected in 75% ethanol for 30 seconds, immersed in 5% NaClO for 1 minute, rinsed three times with sterile water, dried on sterile absorbent paper, placed on potato dextrose agar (PDA), and incubated at 28°C in the dark. After 5 days, 95% of the samples developed similar-appearing colonies. A single isolate, B1-V1, was selected for morphological and molecular characterization. After 15 days of incubation at 28℃ on PDA, colonies of B1-V1 reached a diameter of 80 mm; white mycelium grew slightly above the surface of the plate, was velvety in texture, and produced a yellow pigment. Hyaline, septate hyphae produced verticillate conidia that were branched like broomsticks, and conidiophores were transparent and elliptical with a single conidiophore measuring (2.31 - 4.75) × (5.33 - 8.75) μm (n = 32). The morphology was consistent with a previous description of Clonostachys rosea (Wang et al. 2024). The internal transcribed spacer region (ITS), β-tubulin gene (TUB2) and second subunit of RNA polymerase II gene (RPB2) were amplified by primers ITS1/ITS4 (Wang et al. 2024), T1/βt2b (Wang et al. 2024). and RPB2F/RPB2R (Long et al. 2021), respectively. The corresponding sequences from B1-V1 were submitted to GenBank under accession numbers PV368674 (ITS), PV390661 (TUB2), and PV390662 (RPB2). According to a BLAST search, the pathogen displayed the highest sequence similarity to strains GY12 (ITS: OR789466.1, identities: 545/545 bp), JABY1 (TUB2: OP868694.1, identities: 601/617bp) and HZL-6-8 (RPB2: PP486409.1, identities: 896/900bp). A phylogenetic tree was constructed based on concatenated ITS-TUB2-RPB2 sequences using Maximum Parsimony methods by MEGA7 software, revealing that the isolate was most closely related to C. rosea strain TMB (ITS: 491/498bp, TUB2: 311/455bp, RPB2:753/753bp). To confirm pathogenicity, both cuttings derived from branches of two-year-old plants of L. japonica Thunb. and one-year-old plants (n = 6 per group) were surface-sterilized with 75% ethanol. Roots were wounded with a sterile needle and soaked in a 4 × 10⁷ conidia/mL suspension of isolate B1-V1 for 20 days. After inoculation, symptoms including leaf wilting, yellowing, and rot browning and rot were observed, and the number of new roots significantly decreased. Colonies re-isolated from symptomatic roots were morphologically consistent with the original inoculum, thus fulfilling K","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144822247","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":"Innovative control of the cucurbit powdery mildew: Combining nanoencapsulated dsRNA and low-dose fungicides for sustainable crop protection.","authors":"Nisrine Bakhat, Yandira Morales, David Fernández-Salvatierra, Leonardo Velasco, Alejandro Perez-Garcia, Dolores Fernandez-Ortuno","doi":"10.1094/PDIS-05-25-1120-RE","DOIUrl":"https://doi.org/10.1094/PDIS-05-25-1120-RE","url":null,"abstract":"<p><p>The rise of fungicide-resistant pathogens and increasingly strict regulatory frameworks have heightened the demand for sustainable alternatives in plant disease control. This study assesses the potential of spray-induced gene silencing (SIGS) targeting SdhC, a critical subunit of the mitochondrial succinate dehydrogenase (SDH) complex and determinant of SDHI fungicide resistance, for managing Podosphaera xanthii, the causal agent of cucurbit powdery mildew. To evaluate this approach, PxSdhC double-stranded RNA (dsRNA) was initially infiltrated into melon cotyledons, resulting in a 65% reduction in fungal biomass and a 60% decrease in SdhC gene expression, validating its effectiveness for SIGS applications. A key achievement of this study was the demonstration that strong disease control can be achieved with substantially reduced doses of SDHI fungicides when combined with PxSdhC-dsRNA, providing the first direct evidence of the synergistic potential of this strategy. Building on these results, greenhouse trials were conducted in which dsRNA was applied in both naked and carbon dot (CD)-nanoencapsulated forms, alone or in combination with low doses of the SDHI fungicides boscalid and fluopyram. Nanoencapsulation enhanced dsRNA stability and extended gene silencing effects, achieving up to 69% and 53% disease suppression at 14- and 21-days post-inoculation, respectively. Moreover, combined treatments with PxSdhC-dsRNA-CD and low-dose fungicides exhibited synergistic effects, with disease suppression ranging from 33% to 91%, depending on isolate resistance levels. Sensitive and low-resistance isolates responded effectively, while efficacy declined in highly resistant ones. In vitro specificity assays confirmed that PxSdhC-dsRNA selectively inhibited Botrytis cinerea, a species with high SdhC sequence homology, without affecting unrelated fungi. Altogether, these results highlight the promise of gene-targeted, nanoformulated dsRNA as an effective, precise, and environmentally friendly strategy for integrated disease management, capable of boosting the performance of low-dose fungicide applications and reducing chemical input.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144822249","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>Bacillus</i> Species Interfere with Infective Structures of <i>Colletotrichum</i> spp. and Reduce Symptoms of Apple Bitter Rot in Post-Harvest.","authors":"Débora Petermann, Nicolly C Xavier, Rafaele Regina Moreira, Marcos P Rosa, Walmes M Zeviani, Miguel Noseda, Louise Larissa May De Mio","doi":"10.1094/PDIS-05-25-0970-RE","DOIUrl":"https://doi.org/10.1094/PDIS-05-25-0970-RE","url":null,"abstract":"<p><p>Colletotrichum species cause bitter rot (BR) in apples, with symptoms typically manifesting at harvest or during storage. The efficacy of chemical control is limited, and the use of fungicides may lead to the selection of resistant isolates. As a sustainable alternative, biological control methods, i.e., Bacillus spp., have been used to control diseases caused by Colletotrichum spp. This study evaluated the effects of B. subtilis, B. velezensis, and B. amyloliquefaciens on conidial germination (CG), mycelial growth (MG), and suppression of BR in apples. The impact of these bacterial strains on MG of five Colletotrichum species (C. chrysophilum, C. limetticola, C. melonis, C. nymphaeae and C. siamense) was assessed. For B. velezensis, currently under development as a biocontrol product, both the biomass and supernatant fractions were evaluated and compared with the commercial formulations Serenade (B. subtilis) and Duravel (B. amyloliquefaciens). For postharvest control of BR, 'Gala' apples were treated with bacterial suspensions or fungicides and subsequently inoculated with conidia from three Colletotrichum isolates. Captan, dithianon, and metiram+pyraclostrobin served as chemical standards. All the tested Bacillus strains significantly inhibited MG across the Colletotrichum species evaluated. Bacillus velezensis biomass reduced both CG and MG of C. nymphaeae and C. chrysophilum. Metiram+pyraclostrobin inhibited more than 98.2% of CG, while B. amyloliquefaciens achieved 63% inhibition of CG of C. chrysophilum. All fungicides reduced the incidence of BR by over 75% while B. amyloliquefaciens and B. subtilis gave variably reduced incidence of the disease depending on the isolate, experiment, and concentration.</p>","PeriodicalId":20063,"journal":{"name":"Plant disease","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144817347","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}