Grapevine Pinot gris virus spreads in infected vineyards: latent infections have no direct impact on grape production.

BACKGROUND: Grapevine Pinot gris virus (GPGV) infects grapevines worldwide and causes symptoms such as chlorotic mottling and deformations on leaves, stunted shoots and short panicles, or none of these symptoms if it appears as latent infection. So far, the consequences of GPGV infections for winegrowers are difficult to assess since important information such as plant performance at different GPGV infection levels and symptom expression are not fully clarified. METHODS: In order to investigate the course of GPGV spread, annual visual evaluations and ELISA tests were conducted over 3-4 consecutive years in four GPGV-infected vineyards in southern Germany: GEM, HEC, NIM, and REI. The program PATCHY was used to analyze spatial disease patterns. Sanger sequencing was used to determine virus isolates in vines at different GPGV infection levels, to test their respective influence on symptom expression. Yield and GrapeScan (FTIR) analyses were conducted to test the impact of different GPGV infection levels and isolates on fruit quantity and quality. RESULTS: GPGV infections significantly increased in all four vineyards (GEM 22-32%, HEC 50-99%, NIM 83-90%, REI 56-76%) with significant spreading patterns across and along rows. Specific symptom progression patterns were not observed. According to our results, the virus isolate has an influence on whether symptoms develop during a GPGV infection. While yield analyses revealed that yield losses only occur in symptomatic vines and range from 13 to 96% depending on the severity of symptoms, latent infections have no impact on grape production. No relevant effects of GPGV infections on must quality were observed. CONCLUSIONS: Secondary spread of GPGV was observed in all vineyards monitored, indicating vector-borne transmission that is likely to be accelerated by human viticultural management. GPGV should be further monitored to prevent the accumulation of detrimental symptomatic isolates. The results of this study can be used to assess the risk of GPGV to viticulture and should be considered when developing management strategies against the virus.

Application of Biotechniques for In Vitro Virus and Viroid Elimination in Pome Fruit Crops.

Sustainable production of pome fruit crops is dependent upon having virus-free planting materials. The production and distribution of plants derived from virus- and viroid-negative sources is necessary not only to control pome fruit viral diseases but also for sustainable breeding activities, as well as the safe movement of plant materials across borders. With variable success rates, different in vitro-based techniques, including shoot tip culture, micrografting, thermotherapy, chemotherapy, and shoot tip cryotherapy, have been employed to eliminate viruses from pome fruits. Higher pathogen eradication efficiencies have been achieved by combining two or more of these techniques. An accurate diagnosis that confirms complete viral elimination is crucial for developing effective management strategies. In recent years, considerable efforts have resulted in new reliable and efficient virus detection methods. This comprehensive review documents the development and recent advances in biotechnological methods that produce healthy pome fruit plants. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Comparative Performance Evaluation of Double-Stranded RNA High-Throughput Sequencing for the Detection of Viral Infection in Temperate Fruit Crops.

There is limited information on the compared performances of biological, serological. and molecular assays with high-throughput sequencing (HTS) for viral indexing in temperate fruit crops. Here, using a range of samples of predetermined virological status, we compared two performance criteria (inclusivity and analytical sensitivity) of enzyme-linked immunosorbent assay (ELISA), molecular hybridization, reverse transcription (RT)-PCR, and double-stranded RNA (dsRNA) HTS for the detection of a total of 14 viruses (10 genera) and four viroids (three genera). When undiluted samples from individual plants were used, ELISA had the lowest performance, with an overall detection rate of 68.7%, followed by RT-PCR (82.5%) and HTS (90.7%; 100% if considering only viruses). The lower performance of RT-PCR reflected the inability to amplify some isolates as a consequence of point mutations affecting primer-binding sites. In addition, HTS identified viruses that had not been identified by other assays in nearly two-thirds of the samples. Analysis of serial dilutions of fruit tree samples allowed comparison of analytical sensitivities for various viruses. ELISA showed the lowest analytical sensitivity, but RT-PCR showed higher analytical sensitivity than HTS for most of the samples. Overall, these results confirm the superiority of HTS over biological indexing in terms of speed and inclusivity and show that while the absolute analytical sensitivity of RT-PCR tends to be higher than that of HTS, PCR inclusivity is affected by viral genetic diversity. Taken together, these results make a strong case for the implementation of HTS-based approaches in fruit tree viral testing protocols supporting quarantine and certification programs.

Multiplex PCR method for the detection of human norovirus, Salmonella spp., Shigella spp., and shiga toxin producing Escherichia coli in blackberry, coriander, lettuce and strawberry.

A multiplex PCR method was developed for the simultaneous detection of murine norovirus (MNV-1) as a surrogate for human norovirus (HuNoV) GI and GII, Salmonella spp., Shigella spp., and Shiga toxin producing Escherichia coli (STEC) in fresh produce. The toxicity of the glycine buffer on bacterial pathogens viability was evaluated. The growth of each of the three pathogens (previously stressed) was evaluated at 35 and 41.5 °C in modified buffered peptone water (mBPW) and trypticase soy broth (TSB), supplemented with vancomycin, novobiocin and brilliant green at two concentration levels. The selected conditions for simultaneous enrichment were: 41.5 °C/mBPW/supplemented with 8 ppm vancomycin, 0.6 ppm novobiocin and 0.2 ppm brilliant green. The pathogens and aerobic plate count (APC) growth was evaluated in the enrichment of lettuce, coriander, strawberry and blackberry under the best enrichment conditions. Starting from 1 to 10 CFU/mL, Salmonella reached from 7.63 to 8.91, Shigella 6.81 to 7.76 and STEC 7.43 to 9.27 log CFU/mL. The population reached for the APC was 5.11-6.56 log CFU/mL. Simultaneous detection by PCR was done using designed primers targeting invA, ipaH, stx1 and stx2 genes, and MNV-1. The detection sensitivity was 10-100 PFU for the MNV-1 and 1-10 CFU for each pathogenic bacteria. This protocol takes 6 h for MNV-1 and 24 h for Salmonella spp., Shigella spp., and STEC detection from the same food portion. In total, 200 samples were analyzed from retail markets from Queretaro, Mexico. Two strawberry samples were positive for HuNoV GI and one lettuce sample was positive for STEC. In conclusion, the method developed in this study is capable of detecting HuNoV GI and GII, Salmonella spp., Shigella spp and STEC from the same fresh produce sample.

Physicochemical Parameters Affecting Norovirus Adhesion to Ready-To-Eat Foods.

The adhesion of noroviruses to strawberry, turkey slices, ham, and cheddar cheese was studied using murine norovirus 1 (MNV-1) as a surrogate for human norovirus (NoV). Based on plaque assay, the recovery and adhesion of MNV-1 depended on the food type (turkey versus strawberry), pH of the initial suspension buffer (pH 4 versus pH 7), and food fat composition (C8 versus C18). Recovery of infectious particles from turkey was 68% compared to 9.4% from strawberry. On turkey, adhesion of MNV-1 was lower at pH 7 (pH of fecal matter), and virus particles adhered to this pH were recovered more easily (33,875 PFU) than at pH 4 (pH of vomitus). The presence of fat and the composition of fatty acids seemed to increase MNV-1 recovery and adherent viral particles recovered but did not affect adhesion (68% on fat-free turkey and regular turkey). Adherent MNV-1 particles recovered from stainless steel coated with saturated fatty acid (C8, C14, C18) increased significantly with chain length (P < 0.05), but adhesion did not seem to change. Using liquid droplet contact angle to measure surface energy, it was deduced that hydrophobic interactions contribute considerably to the adhesion of MNV-1 to stainless steel, polyvinyl chloride, and high-density polyethylene. IMPORTANCE Ready-to-eat (RTE) foods are major vehicles of transmission of foodborne viral pathogens, including NoV. The high incidence of gastroenteritis caused by viruses is due largely to their persistence in the environment and adhesion to different kinds of surfaces in the food industry, including the foods themselves. Compared with bacteria, adhesion of viruses to surfaces is poorly understood. Better knowledge of the physicochemical parameters involved in the adhesion of NoV to ready-to-eat foods is essential to devising effective strategies for reducing the persistence and, thus, the transmission of this virus.

Identification and characterization of a novel virus associated with an eriophyid mite in extracts of fruit trees leaves.

Eriophyid mites are commonly found on the leaf surface of different plant species. In the present study, a novel virus associated with an eriophyid mite species was detected using high-throughput sequencing (HTS) of total RNA from fruit tree leaves, primarily growing under greenhouse conditions. The complete genome sequence was characterized using rapid amplification of cDNA ends followed by Sanger sequencing, revealing a genome of 8885 nucleotides in length. The single positive-stranded RNA genome was predicted to encode typical conserved domains of members of the genus Iflavirus in the family Iflaviridae. Phylogenetic analysis showed this virus to be closely related to the unclassified iflavirus tomato matilda associated virus (TMaV), with a maximum amino acid sequence identity of 59% in the RNA-dependent RNA polymerase domain. This low identity value justifies the recognition of the novel virus as a potential novel iflavirus. In addition to a lack of graft-transmissibility evidence, RT-PCR and HTS detection of this virus in the putative host plants were not consistent through different years and growing seasons, raising the possibility that rather than a plant virus, this was a virus infecting an organism associated with fruit tree leaves. Identification of Tetra pinnatifidae HTS-derived contigs in all fruit tree samples carrying the novel virus suggested this mite as the most likely host of the new virus (p-value < 1e-11), which is tentatively named "eriophyid mite-associated virus" (EMaV). This study highlights the importance of a careful biological study before assigning a new virus to a particular plant host when using metagenomics data.

Examining the persistence of human Coronavirus 229E on fresh produce.

Human coronaviruses (HCoVs) are mainly associated with respiratory infections. However, there is evidence that highly pathogenic HCoVs, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Middle East Respiratory Syndrome (MERS-CoV), infect the gastrointestinal (GI) tract and are shed in the fecal matter of the infected individuals. These observations have raised questions regarding the possibility of fecal-oral route as well as foodborne transmission of SARS-CoV-2 and MERS-CoV. Studies regarding the survival of HCoVs on inanimate surfaces demonstrate that these viruses can remain infectious for hours to days, however, there is limited data regarding the viral survival on fresh produce, which is usually consumed raw or with minimal heat processing. To address this knowledge gap, we examined the persistence of HCoV-229E, as a surrogate for highly pathogenic HCoVs, on the surface of commonly consumed fresh produce, including: apples, tomatoes, cucumbers and lettuce. Herein, we demonstrated that viral infectivity declines within a few hours post-inoculation (p.i) on apples and tomatoes, and no infectious virus was detected at 24h p.i, while the virus persists in infectious form for 72h p.i on cucumbers and lettuce. The stability of viral RNA was examined by droplet-digital RT-PCR (ddRT-PCR), and it was observed that there is no considerable reduction in viral RNA within 72h p.i.

One-step duplex RT-droplet digital PCR assay for the detection of norovirus GI and GII in lettuce and strawberry.

The study was designed to develop a sensitive one-step duplex reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) to detect norovirus genogroup I and II (NoV GI and GII) in lettuce and strawberry. The specificity, sensitivity, repeatability and robustness of the assay was compared with RT-qPCR. The lowest concentration detected by RT-ddPCR for NoV GI and NoV GII were 4.68 and 8.47 copies/µL respectively, much lower than that of RT-qPCR with a number of 46.8 and 84.7 copies/µL, respectively. Lettuce and strawberry samples were artificially contaminated with NoV GI and GII suspensions, with inoculum size of 3.00 × 106 to 1.70 × 108 copies and 4.80 × 105 to 2.50 × 107 copies, respectively. Strawberry spiked with low inoculum size revealed positive results by RT-ddPCR, while recorded negative by RT-qPCR. Meanwhile, RT-ddPCR also showed a higher average recovery rate for NoV in lettuce and strawberry than RT-qPCR.The limit of detection (LoDs) of RT-ddPCR for NoVs in lettuce was 2.32 × 104 copies/25g (NoV GI) and 2.36 × 104 ciopies/25g (NoV GII), and that in strawberry was 2.56 × 104 copies/25g (NoV GI) and 2.64 × 104 ciopies/25g (NoV GII), which were 10 folds lower than that of RT-qPCR. The developed duplex RT-ddPCR assay exhibited stability and increased capacity to resist inhibitors in food samples with low concentration of NoV, making it a reliable method to avoid false negative result as opposed to RT-qPCR. In conclusion, one-step RT-ddPCR method developed in this study is pertinent in detecting foodborne virus such as NoV.

Comparative Study of Metagenomics and Metatranscriptomics to Reveal Microbiomes in Overwintering Pepper Fruits.

Red pepper (Capsicum annuum, L.), is one of the most important spice plants in Korea. Overwintering pepper fruits are a reservoir of various microbial pepper diseases. Here, we conducted metagenomics (DNA sequencing) and metatranscriptomics (RNA sequencing) using samples collected from three different fields. We compared two different library types and three different analytical methods for the identification of microbiomes in overwintering pepper fruits. Our results demonstrated that DNA sequencing might be useful for the identification of bacteria and DNA viruses such as bacteriophages, while mRNA sequencing might be beneficial for the identification of fungi and RNA viruses. Among three analytical methods, KRAKEN2 with raw data reads (KRAKEN2_R) might be superior for the identification of microbial species to other analytical methods. However, some microbial species with a low number of reads were wrongly assigned at the species level by KRAKEN2_R. Moreover, we found that the databases for bacteria and viruses were better established as compared to the fungal database with limited genome data. In summary, we carefully suggest that different library types and analytical methods with proper databases should be applied for the purpose of microbiome study.

Cucumber mosaic virus infection modulated the phytochemical contents of Passiflora edulis.

Cucumber mosaic virus (CMV) caused huge agricultural impact on Passiflora edulis. However, the interactions between CMV and P. edulis are poorly unknown, which lead to lack of prevention and control measures. In this study, we identified the infection of CMV in P. edulis through modern small RNA sequencing (sRNA-seq) technology combined with traditional electron microscope and polymerase chain reaction (PCR) methods. We also confirmed CMV infection adversely affected or modulated the contents of phytochemicals and further injured the development of P. edulis; inversely, P. edulis modulated its resistance to CMV stress by increasing the levels of secondary metabolites and the activities of antioxidant enzymes components. This is of significant importance to understand the interaction between virus infection and plant host.

Transmission studies of the newly described apple chlorotic fruit spot viroid using a combined RT-qPCR and droplet digital PCR approach.

The transmission of the apscaviroid tentatively named apple chlorotic fruit spot viroid (ACFSVd) was investigated using a one-step reverse-transcription (RT) droplet digital PCR assay for absolute quantification of the viroid, followed by quantification of relative standard curves by RT-qPCR. Our results indicate that ACFSVd is effectively transmitted by grafting, budding and seeds. No transmission has yet been observed to the viroid-inoculated pome fruit species Pyrus sp. and Cydonia sp. ACFSVd was detected in viruliferous aphids (Myzus persicae, Dysaphis plantaginea) and in codling moths (Cydia pomonella). The viroid was also detected systemically in the infected hemiparasitic plant Viscum album subsp. album (mistletoe).

Effect of asymptomatic infection with southern tomato virus on tomato plants.

Southern tomato virus (STV) is often found infecting healthy tomato plants (Solanum lycopersicum). In this study, we compared STV-free and STV-infected plants of cultivar M82 to determine the effect of STV infection on the host plant. STV-free plants exhibited a short and bushy phenotype, whereas STV-infected plants were taller. STV-infected plants produced more fruit than STV-free plants, and the germination rate of seeds from STV-infected plants was higher than that of seeds from STV-free plants. This phenotypic difference was also observed in progeny plants (siblings) derived from a single STV-infected plant in which the transmission rate of STV to progeny plants via the seeds was approximately 86%. These results suggest that the interaction between STV and host plants is mutualistic. Transcriptome analysis revealed that STV infection affects gene expression in the host plant and results in downregulation of genes involved in ethylene biosynthesis and signaling. STV-infected tomato plants might thus be artificially selected due to their superior traits as a crop.

Resurgence of an international hepatitis A outbreak linked to imported frozen strawberries, Germany, 2018 to 2020.

Following outbreaks linked to frozen strawberries in Sweden and Austria in 2018, 65 cases linked to the same hepatitis A virus strain were detected in Germany between October 2018 and January 2020, presenting in two waves. Two case-control studies and a comparison of cases' consumption frequencies with purchase data from a large consumer panel provided strong evidence for frozen strawberry cake as the main vehicle of transmission. Of 46 cases interviewed, 27 reported consuming frozen strawberry cake and 25 of these identified cake(s) from brand A spontaneously or in product picture-assisted recall. Trace back investigations revealed that the Polish producer involved in the previous outbreaks in Sweden and Austria had received frozen strawberries from Egypt via a wholesaler that also delivered frozen strawberries to manufacturer of brand A. Phylogenetic analyses linked the outbreak strain to similar strains formerly isolated from sewage, stool and strawberries in Egypt. Complete trace back and timely recall of products with strong evidence of contamination is important to control an outbreak and prevent later resurgence, particularly for food items with a long shelf life. Continued molecular surveillance of hepatitis A is needed to identify outbreaks and monitor the success of food safety interventions.

Silencing of one copy of the translation initiation factor eIFiso4G in Japanese plum (Prunus salicina) impacts susceptibility to Plum pox virus (PPV) and small RNA production.

BACKGROUND: In plants, host factors encoded by susceptibility (S) genes are indispensable for viral infection. Resistance is achieved through the impairment or the absence of those susceptibility factors. Many S genes have been cloned from model and crop species and a majority of them are coding for members of the eukaryotic translation initiation complex, mainly eIF4E, eIF4G and their isoforms. The aim of this study was to investigate the role of those translation initiation factors in susceptibility of stone fruit species to sharka, a viral disease due to Plum pox virus (PPV). RESULTS: For this purpose, hairpin-inducing silencing constructs based on Prunus persica orthologs were used to generate Prunus salicina (Japanese plum) 4E and 4G silenced plants by Agrobacterium tumefaciens-mediated transformation and challenged with PPV. While down-regulated eIFiso4E transgenic Japanese plums were not regenerated in our conditions, eIFiso4G11-, but not the eIFiso4G10-, silenced plants displayed durable and stable resistance to PPV. We also investigated the alteration of the si- and mi-RNA profiles in transgenic and wild-type Japanese plums upon PPV infection and confirmed that the newly generated small interfering (si) RNAs, which are derived from the engineered inverted repeat construct, are the major contributor of resistance to sharka. CONCLUSIONS: Our results indicate that S gene function of the translation initiation complex isoform is conserved in Prunus species. We discuss the possibilities of using RNAi silencing or loss-of-function mutations of the different isoforms of proteins involved in this complex to breed for resistance to sharka in fruit trees.

Apple chlorotic fruit spot viroid: a putative new pathogenic viroid on apple characterized by next-generation sequencing.

Viroid-like symptoms were observed in 2016 on apple fruits of the cultivar "Ilzer Rose" in southern Burgenland, Austria. Preliminary molecular biological investigations indicated that the symptoms were caused by a new unknown viroid. Therefore, new primers were designed, and the whole genome sequence of the viroid (354 nt) was determined by next-generation amplicon sequencing using the Illumina MiSeq® platform (San Diego, California, USA). The viroid secondary structure has a rod-like conformation and contains conserved regions (the TCR, CCR upper strand, and CCR lower strand) that are characteristic of members of the genus Apscaviroid. Based on our results and the demarcation criteria for viroids, the tentatively named "apple chlorotic fruit spot viroid" should be considered a putative new member of the genus Apscaviroid.

Outbreak of hepatitis A genotype IB in Australia associated with imported frozen pomegranate arils.

Locally acquired hepatitis A infection is re-emerging in Australia owing to person-to-person outbreaks among men who have sex with men and imported frozen produce. This paper describes a multi-state foodborne outbreak in the first half of 2018. Enhanced human epidemiological investigation including a case-control study, as well as microbial surveillance and trace-back investigations concluded that the outbreak was caused by consumption of imported frozen pomegranate arils. A total of 30 cases of hepatitis A infection, genotype IB with identical sequences met the outbreak case definition, including 27 primary cases and three secondary cases. Twenty-five (83%) of the cases were hospitalised for their illness and there was one death. Imported frozen pomegranate arils from Egypt were strongly implicated as the source of infection through case interviews (19 of 26 primary cases) as well as from a case-control study (adjusted odds ratio 43.4, 95% confidence interval 4.2-448.8, P = 0.002). Hepatitis A virus (HAV) was subsequently detected by polymerase chain reaction in two food samples of the frozen pomegranate aril product. This outbreak was detected and responded to promptly owing to routine genetic characterisation of HAVs from all hepatitis A infections in Australia as part of a national hepatitis A enhanced surveillance project. This is now the third outbreak of hepatitis A in Australia from imported frozen fruits. A re-assessment of the risk of these types of imported foods is strongly recommended.

Key characteristics of foods with an elevated risk for viral enteropathogen contamination.

Viral enteropathogens are one of the leading causative agents of foodborne illnesses in both the United States and the European Union. While human noroviruses and hepatitis A virus cause the vast majority of outbreaks and illnesses, there are handful of human enteric viruses that contribute to sporadic outbreaks worldwide including astrovirus, sapovirus, rotavirus, enterovirus and Aichi virus. In addition, hepatitis E virus is increasingly being recognized as an emerging zoonotic threat within the food supply. This review aims to briefly describe the primary human enteric viruses of concern with respect to foodborne transmission. Next, we focus on the contamination and persistence of these viruses within three high-risk food commodities-leafy greens, soft red fruits and bivalve mollusks. As opposed to detailing the specific routes by which these foods can be contaminated with enteric viruses, we have chosen to focus on their persistence and specific interactions within the food itself. Therefore, the processes of attachment and internalization of the viruses in foods have been emphasized. Looking forward, the implications of these specific interactions of human enteric viruses with leafy greens, soft red fruits and bivalve mollusks are briefly considered within the context of future prevention and control strategies.

Prevalence of Norovirus in produce sold at retail in the United Kingdom.

To acquire data on contamination with Norovirus in berry fruit and salad vegetables in the United Kingdom, one thousand one hundred and fifty two samples of fresh produce sold at retail in the UK were analysed for Norovirus. Of 568 samples of lettuce, 30 (5.3%) were Norovirus-positive. Most (24/30) lettuce samples which tested positive for Norovirus were grown in the UK and 19 of those 24 samples contained NoV GI. Seven/310 (2.3%) samples of fresh raspberries were Norovirus-positive. Most (6/7) of the positively-testing fresh raspberry samples were imported, but no predominance of a genogroup, or any seasonality, was observed. Ten/274 (3.6%) samples of frozen raspberries were Norovirus-positive. The country of origin of the positively-testing frozen raspberry samples was not identified in most (7/10) instances. The collected data add to the currently limited body of prevalence information on Norovirus in fresh produce, and indicate the need for implementation of effective food safety management of foodborne viruses.

Surveillance of norovirus contamination in commercial fresh/frozen berries from Heilongjiang Province, China, using a TaqMan real-time RT-PCR assay.

Norovirus (NoV), a major food-borne virus, causes non-bacterial acute gastroenteritis in humans. Berries are generally harvested from low-growing bushes by hand and are minimally processed before being sold to consumers. Therefore, the consumption of berries has been linked to numerous food-borne gastroenteritis outbreaks caused by NoV in many countries. We performed a survey of NoV contamination in commercial fresh/frozen berry fruits collected from 2016 to 2017 in the Heilongjiang Province, the main berry-producing area in China, using a TaqMan-based real-time reverse transcription-PCR assay. Among 900 frozen and 900 fresh domestic retail berry samples, the prevalence of NoV was 9% (81/900) and 12.11% (109/900), including 35.80% (29/81) and 29.36% (32/109) of genotype GI alone, 54.32% (44/81) and 60.55% (66/109) of GII alone, and 9.88% (8/81) and 10.09% (11/109) of both GI and GII, respectively. No NoV was detected among the 677 frozen berry samples for export. Thus, the occurrence of NoV contamination was significantly higher in domestic berries than in exported berries and higher in fresh berries than in frozen berries. This study highlights the need for further risk surveillance for NoV contamination in berries produced in the Heilongjiang Province and recommends region-extended monitoring of retail berries for NoV.

Occurrence and Molecular Variability of Kiwifruit Viruses in Actinidia deliciosa 'Xuxiang' in the Shaanxi Province of China.

Kiwifruit (Actinidia spp.) is an economically substantial fruit crop with China the main producer. China is the primary source of wild kiwifruit and the largest producer of kiwifruit in terms of both production and planting area, and Shaanxi province is the largest kiwifruit producer in China. Previous studies reported presence of kiwifruit viruses in Actinidia chinensis. In this study, six viruses were identified in kiwifruit 'Xuxiang' (A. deliciosa) in Shaanxi, China. The incidence, distribution, and genetic diversity of these viruses were studied. The results showed that Actinidia virus A (AcVA), Actinidia virus B (AcVB), Actinidia chlorotic ringspot-associated virus (AcCRaV), cucumber mosaic virus (CMV), apple stem grooving virus (ASGV), and potato virus X (PVX) were the main viruses infecting Xuxiang kiwifruit in Shaanxi, China. Incidence of the various viruses with both single and multiple infection varied with different kiwifruit-growing counties. For single virus infection, the highest and the lowest numbers of samples infected were about 22 for AcCRaV and 0 for AcVB in Meixian out of 170 samples, 12 for AcVA and 0 for CMV in Zhouzhi out of 120 samples, 10 for AcVA and 0 for AcVB, AcCRaV, ASGV, PVX, and CMV in Yangling out of 70 samples, and 8 for AcCRaV and CMV and 0 for AcVA, AcVB, ASGV, and PVX in Hanzhong out of 80 samples, respectively. Samples which were multiply infected with two or more viruses were also detected. Analysis of the phylogenetic tree of these viruses showed some genetic variability in the AcVA, AcVB, and AcCRaV isolates of Shaanxi kiwifruit. There was no obvious molecular variation in the coat protein genes of ASGV, CMV, and PVX virus isolates from Shaanxi kiwifruit. The present study is the first large-scale survey of kiwifruit viruses in Shaanxi, China. To our knowledge, this is the first report of PVX infecting kiwifruit and the first report of molecular variability of AcVA, AcVB, and AcCRaV. These results provide important data for studying the genetic evolution of AcVA, AcVB, AcCRaV, ASGV, CMV, and PVX.