Papaya ringspot virus W-type (PRSV W) and cucumber mosaic virus (CMV) severely damage cucurbits worldwide. Recently, we showed that the attenuated mutant PRSV WAC protects cucurbits against severe PRSV W infection. Here, recombinants WAC-CP, WAC-CPn, and WAC-CPc, respectively carrying the whole, N-terminal half, and C-terminal half of the CMV CP reading frame, were constructed. They induced attenuated symptoms followed by recovery in horn melon (Cucumis metuliferus) plants, similar to WAC. In Chenopodium quinoa plants, all recombinants induced infection without lesions. In horn melon plants, all recombinants remained stable after seven transfers and displayed a zigzag accumulation pattern of the beneficial protective virus, similar to WAC. From three tests with 30 plants, WAC-CP provided 100% protection one month after the challenge with PRSV W-CI or CMV, showing no severe symptoms. The absence of the challenge virus was verified by local-lesion assay and RT-PCR. Additionally, 93.3% protection was observed against the mixed challenge of W-CI + CMV. Although WAC-CPn and WAC-CPc provided high degrees of protection (76.7% - 100%) against CMV or PRSV W-CI, they only delayed the development of severe symptoms after the mixed challenge. WAC-CP was further tested in muskmelon plants, where it conferred 90.0% or 93.3% protection against W-CI or CMV, respectively, and 76.7% against the mixed challenge. The protein of individual inserts was not detected, whereas small interfering RNA was detected, suggesting that the protection against CMV is mediated by RNA silencing. Thus, WAC-CP has potential for the concurrent control of PRSV W and CMV in cucurbits.

Cucurbit crops like cucumber, melon, squash, and watermelon are vital vegetables grown globally. Their production is under serious threat by viral diseases caused by a wide array of plant viruses including Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV), and Papaya ringspot virus (PRSV). They cause severe yield losses and reduced fruit quality, forming a significant challenge for sustainable cucurbit production. Host plant resistance (HPR) provides a viable, environmentally friendly, and economically sound approach for controlling viral diseases in cucurbits. The present review presents an overview of the status of host resistance to major cucurbit-infecting viruses, including the origin of natural resistance, the pattern of inheritance, and the progress of breeding strategies. Conventional breeding, marker-assisted selection (MAS), transgenic methodology, and genome editing tools have all played roles in generating virus-resistant varieties. Nonetheless, the speedy development of viral strains, collapse of resistance, and narrow genetic diversity in certain cucurbit crops are still challenges. Combining genomic resources, high-density phenotyping, and bioinformatics is enabling the discovery and deployment of enduring resistance genes. In addition, utilization of wild relatives and landraces as a source of resistance is receiving increased interest. This review highlights the importance of interdisciplinarity to engineer broad-spectrum and lasting resistance. Host plant resistance will be critical for food security and decreasing the dependency on chemical controls in cucurbit production systems.

Abstract Background Cucumber mosaic virus (CMV) is vectored by aphids. Infection of Arabidopsis thaliana plants with CMV affects their attractiveness to aphids ( Myzus persicae ) and the performance of aphids confined on these plants. CMV-induced changes in plant-aphid interactions (‘viral manipulation’) may promote transmission. M. persicae , an efficient CMV vector is a ‘generalist’, i.e., it has many plant hosts. A. thaliana is also exploited by crucifer-specialist aphids including Lipaphis erysimi (an efficient CMV vector) and Brevicoryne brassicae (a poor CMV vector). We explored the hypothesis that CMV-induced viral manipulation of aphid behaviour would exert stronger effects on M. persicae than on crucifer-specialists. Results M. persicae , B. brassicae and L. erysimi were released in microcosms and allowed to choose to settle on either CMV-infected or mock-inoculated plants. Initial experiments showed that as systemic CMV infection developed in A. thaliana , aphids of M. persicae were decreasingly likely to settle on infected plants. In subsequent experiments, using plants at 14 days post-infection, it was found that aphids of M. persicae were faster to choose between infected and uninfected plants than specialist aphids, but that both the generalist and specialists were less likely to settle on CMV-infected plants. Olfactometry showed that volatiles emitted by CMV-infected plants attracted M. persicae , and although the specialists showed no significant preferences, greater numbers of aphids of all three species responded when CMV-infected plant volatiles were presented to them. Conclusions As CMV infection develops, A. thaliana becomes less susceptible to aphid colonisation, however, plants continue to emit attractive olfactory cues. This is consistent with a model in which aphids are attracted to infected plants but discouraged from settling (e.g., by gustatory cues), which encourages aphids to carry CMV to non-infected plants. CMV appears to be more successful in manipulating the interactions of A. thaliana with the generalist aphid M. persicae , than with the crucifer specialists B. brassicae or L. erysimi .

This study explores the virome of fifteen peanut cultivars in Korea. Through RNA sequencing, 305 viral contigs associated with cucumber mosaic virus (CMV), peanut mottle virus (PeMoV), bean common mosaic virus (BCMV), and brassica yellows virus (BrYV) were identified, with CMV notably prevalent across samples. Evaluation of viral abundance using viral reads and TPM values revealed CMV dominance in reads and PeMoV prominence in normalized values in select samples. Complete genomes of BCMV, PeMoV, BrYV, and CMV segments were assembled, enabling phylogenetic analysis that uncovered genetic relationships among viral isolates. RT-PCR confirmed BCMV, CMV, and PeMoV presence. Genetic diversity within BCMV was evident through single-nucleotide polymorphism (SNP) analysis, displaying diverse patterns and correlations with viral reads. This study discusses the implications for peanut cultivation, stressing the importance of ongoing research to manage viral diseases. It forms a foundational resource for future investigations into peanut virology, guiding strategies for disease management in peanut crops.

First report of cucumber mosaic virus infecting Physalis angulata L. in China

Daylilies (Hemerocallis spp.) are native to Northeast Asia, including Korea, China, and Japan, and are now widely cultivated as ornamental plants. This study investigated the occurrence of viruses in daylily cultivars at the National Arboretum in Pocheon. A total of 312 leaf samples from 104 cultivars showing virus-like symptoms were collected and analyzed using reverse transcription-polymerase chain reaction and nucleotide sequencing. Three viruses (cucumber mosaic virus [CMV], lily mottle virus [LMoV], and tobacco rattle virus [TRV]) were detected in this study. Of the 312 samples, CMV, LMoV, and TRV were detected in 10 (3.2%), 67 (21.5%), and five (1.6%) samples, respectively. Mixed infections were observed in seven cultivars, with all three viruses detected in three of them. A total of 46 viral isolates were sequenced and deposited to GenBank. Phylogenetic analysis revealed that the isolates were closely related to previously reported isolates from Korea, China, and the United States but formed distinct clades, suggesting host- or region-specific diversification. This is the first report of CMV, LMoV, and TRV infection in daylilies in Korea, providing valuable molecular data for future virus management and disease prevention strategies in Hemerocallis cultivation.

Pre-endophytic colonization of snake gourd (Trichosanthes cucumerina L.) with Piriformospora indica (1% w/v), followed by individual pre-colonizations with Bacillus velezensis (108 CFU mL-1) and arbuscular mycorrhizal fungi (AMF; 1% w/v), significantly mitigated the incidence and severity of snake gourd mosaic disease under laboratory and field conditions. The endophytic treatments effectively suppressed the titres of Papaya ringspot virus (PRSV) and Cucumber mosaic virus (CMV), as confirmed by DAC-ELISA and DAS ELISA analyses. Among the treatments, P. indica pre-colonization resulted in the lowest viral load and delayed symptom expression, followed by B. velezensis and AMF. Enhanced activities of defense-related enzymes viz., peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, catalase and ascorbic acid oxidase were recorded in P. indica-colonized plants, indicating the induction of systemic resistance. SDS-PAGE analysis revealed the induction of a novel 31.57 kDa protein in AMF-treated plants, while, P. indica and B. velezensis colonization altered overall protein profiles relative to the control. Field evaluations demonstrated a marked reduction in disease incidence (88.36% in P. indica, 92.95% in B. velezensis and 99.74% in AMF treatments at 90 DAS), improved vegetative growth and yield, with P. indica recording the highest yield (7.04 kg plant-1).

Passionfruit leaf curl Guangdong virus (PaLCuGdV) is an emerging begomovirus threatening passionfruit production. We established a rapid and simple diagnostic platform based on recombinase polymerase amplification (RPA) combined with lateral flow strip (LFS) technology for reliable detection of PaLCuGdV. Initial polymerase chain reaction (PCR) and reverse transcription-PCR analyses of symptomatic passionfruit leaves identified double infections with PaLCuGdV and euphorbia leaf curl virus (EuLCV), or triple infections with PaLCuGdV, EuLCV, and cucumber mosaic virus (CMV), which were confirmed by Sanger sequencing. Optimization experiments defined 38°C and 15 min as the optimal RPA conditions, yielding consistent amplification between 30°C and 46°C. Sensitivity assays showed that RPA detected PaLCuGdV DNA at concentrations as low as 100 pg total DNA concentration, representing a 10-fold improvement compared with PCR, while maintaining strict specificity for PaLCuGdV in mixed infections without cross-reactivity to EuLCV or CMV. Incorporation of LFS into the assay enabled simple, equipment-free detection, producing results consistent with PCR and suitable for on-site diagnostics by non-specialists. Tissue distribution analyses revealed the presence of PaLCuGdV in all fruit tissues, including exocarp, mesocarp, endocarp, and seeds. PaLCuGdV was consistently detected in both seed coats and cotyledons, indicating a high potential for mode of seed transmission. Together, these results establish RPA-LFS as a sensitive, specific, and portable diagnostic platform for PaLCuGdV, with broad applicability for field-scale surveillance and seed health testing in passionfruit production systems.

In March 2023, unapproved genetically modified (GM) squashes were discovered in South Korea. These were thought to be GM squash ZW20 and CZW3, which are approved for use as food only in Canada and the United States. Because the safety of ZW20 and CZW3 has not been evaluated in Japan, they must continue to be monitored to prevent their unintentional import. In this study, we developed and validated real-time PCR-based qualitative detection methods for ZW20 and CZW3. We evaluated these two detection methods on the basis of PCR amplification efficiency, limit of detection, specificity, and reproducibility to determine their utility for distinguishing and identifying ZW20 and CZW3. One method detects the zucchini yellow mosaic virus resistance gene (ZYMV-coat protein: ZYMV-cp) sequence present in both ZW20 and CZW3, whereas the other method detects the cucumber mosaic virus resistance gene (CMV-coat protein: CMV-cp) sequence present only in CZW3. Our results showed that the ZYMV-cp and CMV-cp detection methods are highly specific for GM squash ZW20 and CZW3, and are sufficiently sensitive, capable of detecting transgenes with at least 6.3 and 3.1 copies per reaction, respectively. Based on this study, we developed the official detection method for GM squash in Japan by combining the ZYMV-cp and CMV-cp detection methods to discriminate between ZW20 and CZW3, making it useful for monitoring food safety.

Attacks by cucumber mosaic virus (VMM) and yellow virus (VK) can kill chili peppers. One control solution is to plant chili peppers among vegetation in a multi-year fallow garden. The objectives of this study were to identify plant species in the fallow garden, then calculate diversity and uniformity, calculate population densities of Myzus persicae and Bemisia tabaci, and calculate the incidence and severity of cucumber mosaic virus and yellow virus diseases. The experimental gardens were located in Ranowangko Dua Village, Kombi District, Minahasa Regency, North Sulawesi Province, Indonesia. Plots for chili planting were surrounded by vegetation of 2.5 m wide. Chili peppers were planted in two rows, with a spacing of 1.5 meters. The spacing between rows was also 1.5 meters. The distance between planting holes and vegetation was 50 cm. Each planting hole was planted with three chili pepper seedlings. Monoculture chili cultivation was carried out in gardens approximately 200 m from natural gardens. Samples for calculating the incidence and severity of VMM and VK, and the population densities of B. tabaci and M. persicae were 20% of the total number of plants per garden. Vegetation sampling for diversity and uniformity calculations was conducted in 1 m x 1 m observation plots located along Z-shaped intersecting lines at 10 m intervals. The plant diversity level was moderate, plant species were evenly distributed, and Nezara viridula was present in the natural chili garden, while B. tabaci was absent. The natural chili garden was protected from VMM and VK invasion, while in monoculture, the incidence of these viral diseases was 80.55 and 85.46%. Keywords: Cucumber mosaic virus, yellow virus, Bemisia tabaci, Myzus persicae, natural cropping pattern

Marine actinomycetes are a promising source for developing new antiviral agents for plant diseases, as they produce a wide variety of bioactive compounds. To date, antiviral activity of marine actinomycetes against plant viruses are rare. The present study proceeded to identify and characterize promising antiviral actinomycetes from Red Sea in Hurghada, Egypt, control Cucumber Mosaic Virus (CMV) and, profile the individual chemical components of bioactive crude extracts. Biological and molecular characterization was performed to identify CMV isolate using RT-PCR and coat protein (CP) gene nucleotide sequences analysis. In squash plants, antiviral, CMV optical density, biochemical responses, and resistance genes expression of Streptomyces extracts (SE1 and SE2) were performed against CMV by disease incidence, severity (%) assays, ELISA technique, physiological analysis, and real-time quantitative PCR (qPCR). Chemical profiling of the two Streptomyces extracts was investigated using GC–MS analysis. Antiviral activity was performed by curative (C), protective (P), and inactivation (I) techniques under greenhouse conditions. The obtained results of the morphological, biochemical, physiological and molecular level studies of the Streptomycetes isolates ph6 and MARH showed similarity towards the species of Streptomyces and identified as Streptomyces variabilis strain ph6 (OQ283766) and Streptomyces sp. strain MARH (OQ283775). Protective treatments (P: SE1 and P: SE2) resulted in disease suppression of 100%, while curative treatments (C: SE1 and C: SE2) by 87% and 100%, and inactivation treatments (I: SE1 and I: SE2) by approximately 70%, and 80% respectively compared to mock-inoculated plants. The absorbance values of ELISA at 405 nm for P: SE1 and P: SE2 were 0.191 ± 0.02, and 0.187 ± 0.00 respectively compared to CMV-infected plants which recorded 0.854 ± 0.00. Levels of ascorbate peroxidase (APX), catalase (CAT) enzymes, proline content, total photosynthetic pigments, and total phenolic compounds were significantly increased in P: SE1 and P: SE2 treated squash plants compared to CMV-infected plants. Moreover, P: SE1 and P: SE2 increased membrane stabilization and reduced electrolyte leakage. The pathogenesis-related (PR) gene such as PR-b1 was overexpressed by about 3.09-, and 10.37-fold increases and PR-2 by 1.07-, and 1.66-fold increases for P: SE1 and P: SE2 respectively compared to the CMV-infected control group. Chemical profiling of the ethyl acetate extracts of Streptomyces variabilis and Streptomyces sp. MARH authenticated the presence of constituents such as 1,3¬Dinitro¬2-imidazolidinone (42.60%), Nephthoside-1,2’,3’,4’-Tetraacetate (76.18%), Tetraphenylporphyrinato dichlorotitanium(IV) (12.42%) and L-Lysine (17.01%) respectively. Our results showed that Streptomyces variabilis and Streptomyces sp. MARH are promising strains for production of antiviral natural products, increasing the phenolic compounds, activity of the antioxidant enzymes, and induction the expression of pathogenesis-related genes to generate systemic acquired resistance (SAR) in squash plants. They also supported the potential use of their extracts as an environmentally friendly novel bio-virocides to sustainably stop the spread of plant viruses.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-31348-9.

Cucumber mosaic virus (CMV) is widely recognized as a damaging pathogen in cucurbits and numerous other horticultural crops. It has an unusually broad host range, with the ability to infect more than 1,000 plant species, and it can also persist in common weed populations, which facilitates its rapid dissemination within cropping systems. Among the many insects that can carry the virus, the aphid Aphis gossypii is generally regarded as the most efficient at transmitting it. Because of these factors, growers frequently report management challenges due to the virus’s broad host range and efficient vector transmission. Plants affected by CMV may show a mixture of symptoms including mosaic mottling, leaf distortion, yellowing, reduced growth, and malformed plant structures. Collectively, these symptoms contribute to reduced plant vigor, diminished yields, and poor-quality marketable produce. Research at the molecular level has shown that much of the virus’s ability to damage plants is linked to components such as the CMV 2b protein, which interferes with RNA-silencing processes and disrupts hormonal regulation, promoting enhanced viral accumulation within host tissues. Several types of laboratory tests are commonly employed to confirm the presence of CMV. ELISA and similar serological assays are still widely used, while molecular techniques such as RT-PCR and LAMP offer higher sensitivity. High-throughput sequencing is becoming increasingly accessible for early detection and strain differentiation. Farmers rarely depend on a single tactic to manage CMV. They integrate crop rotation, hygiene, and vector control. Novel molecular tools such as CRISPR-based genome editing and RNA interference are being explored to enhance detection and resistance strategies, and plant breeders are actively developing CMV-resistant cultivars. While these emerging approaches show promise, long-term field validation is still required. CMV infection increases management costs due to additional monitoring and control inputs. Reducing CMV-related losses requires continued research on virus-host interactions, resistant variety development, and integrated management. Keywords: Cucumber mosaic virus; Cucurbitaceae; aphid transmission; diagnostics; epidemiology; CMV 2b protein; satRNAs; integrated disease management.

Goal. To investigate the species composition and incidence of viral infections in plants of the Cucurbitaceae family in Ukraine, and to identify the possible etiology of their origin. Methods. A range of methods was used in this study, including visual diagnosis, enzyme-linked immunosorbent assay (ELISA) in both indirect and sandwich modifications, electron microscopy, and statistical data analysis. Results. During the study, viral diseases of Cucurbitaceae crops in Ukraine were analyzed based on symptoms. Examination of collected plant samples from the Cucurbitaceae family revealed that 59% of symptomatic specimens were contaminated with viruses. The Cucumber mosaic virus (CMV) antigen was detected in 18% of affected plants, both as a mono-infection and in mixed infections with Watermelon mosaic virus 2 (WMV-2) and Zucchini yellow mosaic virus (ZYMV). The seed transmission pathway of vegetable crop viruses in Ukraine was demonstrated as one of the sources of viral presence in agroecosystems. It was established that CMV is the most hazardous among the identified viruses, with a wide range of host plants and confirmed presence in seeds. Conclusions. As a result of visual diagnostics of plants from the Cucurbitaceae family, various types of virus-like symptoms were observed. Using ELISA, 203 collected plant samples were tested, and 91 samples showed positive results for CMV, WMV-2, and ZYMV. Seed material from 18 Cucurbitaceae cultivars was also examined. ELISA testing of the seed material revealed that 30.5% of the tested samples were contaminated with viruses. The presence of CMV and ZYMV antigens was detected. Viral antigens were identified in cucumber cultivars ‘Kushchovyi’, ‘Zasolochnyi’, and ‘Dalekoskhidnyi’; zucchini cultivars ‘Iskander F1’ and ‘Hrybovskyi’; watermelon cultivar ‘Bochka Medu’; and melon cultivar ‘Medovyi Aromat’.

Bhut Jolokia (Capsicum chinense), a high-value chili pepper indigenous to Northeast India, faces significant yield constraints due to viral diseases. Extensive field surveys conducted during 2020-2021 in the major Bhut Jolokia growing districts of Assam (Jorhat, Golaghat, Lakhimpur, and Dhemaji) revealed a high incidence of virus-like symptoms, including mosaic, mottling, leaf distortion, and stunting. Serological detection using Double Antibody Sandwich Enzyme-Linked Immunosorbent Assay (DAS-ELISA) confirmed the widespread presence of Cucumber mosaic virus (CMV), with disease incidence ranging from 30% to 80%. Molecular analysis further validated these findings. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) using specific primers amplified fragments of the replicase (1052 bp) and coat protein (1130 bp) genes. Nucleotide sequencing of these amplicons revealed 98-100% identity among the Assam isolates. Phylogenetic analysis based on both genes unequivocally clustered the Assam CMV isolates within the subgroup IA, showing closest homology with other Indian isolates from chili. This study provides conclusive evidence of CMV as a predominant viral pathogen infecting Bhut Jolokia in Assam and offers essential genetic information for developing effective management strategies.

Yam (Dioscorea spp.) is a major staple food, contributing significantly to food security and income generation for millions of people worldwide. In 2019, surveys were conducted across the seven agro-ecological zones (AEZs) of Côte d’Ivoire, the third highest producer of yam globally, to ascertain the current status of viral diseases. In the 324 fields surveyed, a total of 1242 yam leaf samples were collected and tested for the presence of Potyvirus yamtesselati (yam mosaic virus, YMV), Potyvirus yamplacidum (yam mild mosaic virus, YMMV), Cucumovirus CMV (cucumber mosaic virus, CMV), and the badnaviruses using PCR, RT-PCR, and RCA followed by Sanger or MinION sequencing. The incidence of yam viral disease varied across the AEZs, with the lowest mean incidence observed in yam farms within the AEZ VII (71.95%) and the highest in AEZ V (88.15%). Viral disease symptom severity was moderate across the country, with more severe symptoms identified in AEZs II and VI. The virus screening revealed a potyvirus detection rate of 35.83% in all the AEZs. YMMV infection (25.12%) is the most prevalent in the samples, followed by YMV infection (15.61%). RCA-MinION sequencing revealed the presence of badnaviruses belonging to the T15 episomal groups K8, K9, and K5. Also, the use of this technique enabled the amplification and sequencing of four full-length episomal badnaviruses, namely Dioscorea bacilliform AL virus in group K8 and Dioscorea bacilliform RT virus in group K5. CMV was not detected in all the samples. It is noteworthy that 22.13% of mixed infections were detected in asymptomatic samples. This study revealed the first occurrence of YMMV in all the AEZs of Côte d’Ivoire. Of the yam species, Dioscorea alata was more widespread (78.03%) than Dioscorea cayenensis-rotundata (21.92%) in the visited fields. Also, D. alata had a highest incidence of YMMV (23.67%) infection than Dioscorea cayenensis-rotundata, while D. cayenensis-rotundata registered the highest incidence of YMV (15.84%) infection compared to D. alata. Phylogenetic analysis of representative of the various viruses detected in the country revealed that the sequences have high diversity for each virus species. This study revealed that viruses infecting yam are widespread and occur in mixed infection, which poses a real threat to yam production in Côte d’Ivoire.

Adzuki bean (Vigna angularis), a major grain legume in Asia, is susceptible to infection by cucumber mosaic virus (CMV), which threatens crop productivity. Here, we characterized the CMV-Pa3 isolate from adzuki bean and investigated the role of specific amino acid residues in the viral 2a protein influencing systemic infection of legumes. Phylogenetic analysis demonstrated that CMV-Pa3 is genetically distinct from other legume-infecting isolates. Inoculation assays revealed that CMV-Pa3 causes systemic infection in adzuki bean, cowpea, soybean, and pea, whereas the control isolate CMV-Rs1 is restricted to inducing local necrotic lesions in cowpea and adzuki bean. Site-directed mutagenesis targeted two conserved amino acid positions (631 and 641) in the 2a protein of CMV-Rs1. Functional analysis showed that residue 631 (Tyr) facilitates systemic infection across all tested legumes, while alteration at position 641 (Ser) alone enables systemic infection in cowpea and pea. These findings identify amino acid determinants in the CMV 2a protein critical for overcoming host restrictions and mediating systemic infection in various leguminous species. This work offers new insights into the molecular mechanisms underlying CMV pathogenicity and host specificity.

Indian valerian (Valeriana jatamansi) is a highly valuable perennial herb that grows at higher altitudes of the Indian Himalayan Region. Essential oil and plant extracts derived from roots and rhizomes are used in flavoring, aromatic and pharmaceutical industries. These underground parts contain bioactive compounds such as valepotriates, including valtrate, didrovaltrate, acevaltrate, valtroxal, valerenic acid and badrinol that are vital for formulation of sedative and anxiolytic drugs. However, several plants were found to exhibit symptoms that are typical of plant virus infection. Infection of virus on plants leads to a severe reduction in plant vigour and essential oil content. Characteristic symptoms include chlorotic or yellow mosaic and stunted plant growth. Foliar samples of diseased plants were taken, DAS-ELISA and reverse transcription polymerase chain reaction (RT-PCR) analyses were used to detect the viruses in the diseased plants. The results revealed that cucumber mosaic virus (CMV) was present in all the plants showing the symptoms of virus infection.

Aphids are phytophagous insects that damage a wide range of plant species and may act as vectors of several pathogens, including Cucumber Mosaic Virus (CMV). CMV seriously affects tomato crops but, although earlier studies have described CMV in northern Italy, little is known about the aphid species in the area that could be involved in its transmission in tomato fields. This three-year survey (2021–2023) focused on monitoring aphid populations in open field tomato crops in the northern Italian provinces of Piacenza, Cremona and Mantua. Sampling included both tomato plants and nearby weeds like Solanum nigrum , Convolvulus arvensis , Abutilon theophrasti or crop like Medicago sativa , which may serve as CMV reservoirs. DNA barcoding of the COI gene, along with morphological analysis where necessary, was used to identify the aphids. A total of 28 aphid taxa were identified from the collected samples, and 89.8% of all identified samples were known CMV vectors. Aphis fabae and Macrosiphum euphorbiae were the most frequently identified species. The greatest number of aphid specimens and species diversity were recorded during the first sampling of each year, whereas the highest sampling diversity was recorded in Piacenza. The current study provides a comprehensive qualitative assessment of the diverse aphid species associated with open field tomato crops in one of the most important districts for their cultivation in Italy.

Chitosan oligosaccharide regulates host defense in pepper plants against cucumber mosaic virus.

Background/Objetive. This study aimed to detect viral agents in four Capsicum chinense cultivars in Tabasco, Mexico; determine disease incidence across five developmental stages; and quantify habanero pepper yield. Experimental development. A field bioassay was established using the cultivars Palenque F1, Jaguar, Orange, and PX-11459057 in a completely randomized design. ImmunoStrips® (Agdia Inc.) were used to detect Orthotospovirus tomatomaculae (tomato spotted wilt virus, TSWV), Cucumber mosaic virus (CMV), Alfalfa mosaic virus (AMV), and Orthotospovirus iridimaculaflavi (iris yellow spot virus, IYSV). PCR was employed for Begomovirus detection. Viral incidence was evaluated at five time points during the crop cycle, and fruit yield (kg plant-1 y t ha-1) and quality were assessed. ANOVA with Tukey’s test (p ≤ 0.05) was applied. Results. ImmunoStrips® tests were negative for all four analyzed viruses. Begomovirus capsicummusive (pepper golden mosaic virus, PepGMV) tested positive by PCR in cultivars Palenque F1, Jaguar, and PX-11459057, with genetic similarity exceeding 98%. Viral symptoms included interveinal chlorosis, mosaic, leaf deformation, and dwarfing. Incidence surpassed 95% at 113 days after transplanting (dat). Fruit production was negatively affected in both quantity and quality. Conclusion. The presence of Begomovirus capsicummusive (PepGMV) was confirmed in habanero pepper in Tabasco, associated with interveinal chlorosis, leaf deformation, and dwarfing, with incidence exceeding 95 % at 113 ddt. Fruit production ranged from 0.1 to 1.41kg ha-1.