Grapevine red blotch virus (GRBV) reduces grapevine vigor, delays grape ripening, reduces sugar content and quality of wines in North America and other continents. To date, the three-cornered alfalfa hopper, Spissistilus festinus, has been clearly identified as a vector in the United States. Since this hopper has not been observed in some vineyards where secondary spread occurs, additional vectors of GRBV are likely. To search for vectors, we conducted a two-year survey collecting live hemipterans from infected vines and surrounding grass, trees, and shrubs. Screening a wide variety of hemipterans from a vineyard with infected plants focuses on relevant insects and avoids the difficulty of rearing multiple species. Most collected insects were immediately used in greenhouse transmission tests to infect clean grapevines, and a subset of insects were frozen for PCR tests. Out of 147 transmission tests using 245 plants, four plants were infected after exposure to the leafhoppers Euscelidius variegatus or Dikraneura absenta or delphacid Nothodelphax sp. Whole-body PCR tests of both E. variegatus and D. absenta frozen directly from the field were positive confirming that they ingested GRBV from the field (no Nothodelphax tested). PCR tests of the cixiid Cixius sp. and leafhoppers Fieberiella florii and Gyponana octolineata were positive but the grapevine transmission tests did not support these as vectors. This survey has identified three hemipterans for further transmission studies and for specific GRBV tests of salivary glands to fully confirm vectoring potential.

‘Thunderhead’ is an erect primocane fruiting blackberry (Rubus subg. Rubus) that produces high yields of berries with excellent firmness and fruit quality for the fresh market. ‘Thunderhead’ is the first erect primocane fruiting blackberry released by the US Department of Agriculture (USDA)–Agricultural Research Service (ARS) Horticultural Crops Production and Genetic Improvement Research Unit (HCPGIRU) breeding program in Oregon, USA. The cultivar contains a genetic background derived primarily from eastern US primocane fruiting blackberry germplasm (developed previously by John Clark at the University of Arkansas System Division of Agriculture, AR, USA) that is predominantly tetraploid (2n = 4x = 28), erect in cane architecture, and has a hybrid mixture of Rubus backgrounds, including strong contributions from species native to eastern and southeastern North America (Rubus argutus, Rubus trivialis).

Rubus yellow net virus (RYNV) belongs to genus Badnavirus. Badnaviruses are found in plants as endogenous, inactive or activatable sequences, and/or in episomal (infectious and active) forms. To assess the state of RYNV in Rubus germplasm, we sequenced the genomes of various cultivars and mined eight raspberry whole genome datasets. Bioinformatics analysis revealed the presence of a diverse array of endogenous RYNV (endoRYNV) sequences that differ significantly in their structure; some lineages have nearly complete, yet non-functional genomes whereas others have rudimentary, short sequence fragments. We developed assays to genotype the main lineages as well as the only known episomal lineage present in the United States. This study discloses the widespread presence of endoRYNVs in commercial raspberries, likely because breeding efforts have focused on a limited pool of germplasm that harbored endoRYNVs.

Screening of blueberry accessions using high throughput sequencing revealed the presence of a new virus. Genomic structure and sequence are similar to that of nectarine stem pitting associated virus (NSPaV), a member of the genus Luteovirus, family Tombusviridae. The full genome of the new luteovirus, tentatively named blueberry virus L (BlVL), was characterized and analyzed. Similar to NSPaV, BlVL does not contain readily identifiable movement proteins in any of the seven isolates sequenced. More than 600 samples collected from five states were screened and 79% were found infected, making BlVL the most widespread blueberry virus in the United States.

A new blueberry virus was discovered using high-throughput sequencing. Using sequence identity values, phylogenetics, and serological and biological properties, we propose the virus, putatively named blueberry virus S (BluVS), to be a distinct species within the genus Carlavirus (family Betaflexiviridae). The genome was analyzed in depth, and an infectious clone was developed to initiate studies on virus pathogenicity. Agroinfiltration of the binary vector construct produced severe systemic symptoms in Nicotiana occidentalis. Back-inoculation using sap from agroinfiltrated N. occidentalis produced identical symptoms to the recipient plants (N. occidentalis), and virus purification yielded flexuous carlavirus-like particles. However, unlike blueberry scorch virus (BlScV), BluVS caused symptomless infection in Chenopodium quinoa and reacted weakly to BlScV antibodies in an enzyme-linked immunosorbent assay. Collectively, the results provide evidence for the distinct speciation of BluVS. The availability of an infectious clone provides tools for future studies on the biology of the virus.

The name Idaeovirus is derived from Rubus idaeus, the host from which Raspberry bushy dwarf virus (type species; RBDV) was first isolated. In 2018 Privet leaf blotch associated virus was recognized as a member of the genus, and Blackcurrant leaf chlorosis associated virus has similar properties and will likely be recognized as member of the genus in the near future. The latter two viruses have been described recently and little is known about their biology. RBDV is present wherever raspberries and blackberries are grown. With the exception of RBDV detected in grapevines in Slovenia and Hungary, Rubus species are the only known natural hosts. Idaeoviruses have bipartite genomes, with the coat protein expressed from a sub-genomic RNA. The only known means of natural transmission are through seed vertically to the next generation, and via pollen to maternal tissue resulting horizontal spread (within field spread).

Rubus yellow net virus (RYNV) belongs to genus Badnavirus. Badnavirids are found in plants as endogenous, inactive sequences, and/or in episomal (infectious and active) forms. To assess the state of RYNV infections, we sequenced the genomes of various Rubus cultivars and mined eight additional published whole genome sequencing datasets. Sequence analysis revealed the presence of a diverse array of endogenous RYNV (endoRYNV) sequences that differ significantly in their structure; some lineages have nearly complete, yet non-functional genomes whereas others have rudimentary, small sequence fragments. We developed assays to genotype the six main endoRYNV lineages as well as the only known episomal lineage in commercial Rubus. This study discloses the widespread presence of endoRYNVs in commercial raspberries, likely because breeding programs have been using a limited pool of germplasm that harbored endoRYNVs.

The first search for viruses in berries (blackberry, raspberry and blueberry) was conducted in Mexico. In September 2017, 24 berry plants displaying virus-like symptoms were sampled in the main berry-producing areas of Mexico and later analyzed for the presence of 29 different viruses via enzyme linked immunosorbent assay (ELISA) and reverse transcription PCR (RT-PCR). Additionally, virus screening was verified using high throughput sequencing (HTS). As a result of this study, two blackberry plants collected in Los Reyes de Salgado, Michoacán were determined positive for tobacco ringspot virus (TRSV; genus Nepovirus), such plants exhibited yellowing and ringspot on leaves. In contrast, the rest of berry samples tested negative for any other virus. This is the first detection of TRSV or any other virus infecting blackberries in Mexico. Lastly, the sequence diversity of characterized TRSV isolates was investigated using an identity matrix and phylogenetics.

In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

Rubus yellow net virus (RYNV) infects Rubus spp., causing a severe decline when present in mixed infections with other viruses. RYNV belongs to the family Caulimoviridae, also known as plant pararetroviruses, which can exist as episomal or integrated elements (endogenous). Most of integrated pararetroviruses are noninfectious; however, a few cases have been reported where they excised from the plant genome and formed infectious particles. Graft transmission onto indicator plants R. occidentalis “Munger” has been the standard test method for RYNV detection in certification programs. Previously, it was noticed that some RYNV PCR-positive plants did not induce symptoms on “Munger”, suggesting an integration event. In this study, bio-indexing and different molecular techniques were employed to differentiate between integrated and episomal RYNV sequences. Reverse transcription-PCR using RYNV-specific oligonucleotides after DNase treatment generated positive results for the virus in graft transmissible isolates (episomal) only. To confirm these results, rolling circle amplification on DNA preparations from the same samples resulted in amplicons identified as RYNV only from plants with graft transmissible RYNV. High-throughput sequencing was used to identify the RYNV-like sequences present in the host DNA. These results indicate the integration of RYNV into the red raspberry genome and highlight the necessity to recognize this phenomenon (integration) in future Rubus quarantine and certification programs.

In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylumNegarnaviricotawas amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy ofNegarnaviricotaas now accepted by the ICTV.

Pathogen-tested foundation plant stocks are the cornerstone of sustainable specialty crop production. They provide the propagative units that are used to produce clean planting materials, which are essential as the first-line management option of diseases caused by graft-transmissible pathogens such as viruses, viroids, bacteria, and phytoplasmas. In the United States, efforts to produce, maintain, and distribute pathogen-tested propagative material of specialty crops are spearheaded by centers of the National Clean Plant Network (NCPN). Agricultural economists collaborated with plant pathologists, extension educators, specialty crop growers, and regulators to investigate the impacts of select diseases caused by graft-transmissible pathogens and to estimate the return on investments in NCPN centers. Economic studies have proven valuable to the NCPN in (i) incentivizing the use of clean planting material derived from pathogen-tested foundation plant stocks; (ii) documenting benefits of clean plant centers, which can outweigh operating costs by 10:1 to 150:1; (iii) aiding the development of disease management solutions that are not only ecologically driven but also profit maximizing; and (iv) disseminating integrated disease management recommendations that resonate with growers. Together, economic studies have reinforced efforts to safeguard specialty crops in the United States through the production and use of clean planting material.

fruit breeding, 'Merton Thornless', semierect blackberry, small fruit, thornlessness, trailing blackberry 'Galaxy' is a thornless, semierect highquality blackberry (Rubus subg.Rubus Watson) that has firm, large, dark fruit suited for the fresh market and that ripen in the early season for this type of blackberry.'Galaxy' was released by the U.S.

Over the last decade, virologists have discovered an unprecedented number of viruses using high throughput sequencing (HTS), which led to the advancement of our knowledge on the diversity of viruses in nature, particularly unraveling the virome of many agricultural crops. However, these new virus discoveries have often widened the gaps in our understanding of virus biology; the forefront of which is the actual role of a new virus in disease, if any. Yet, when used critically in etiological studies, HTS is a powerful tool to establish disease causality between the virus and its host. Conversely, with globalization, movement of plant material is increasingly more common and often a point of dispute between countries. HTS could potentially resolve these issues given its capacity to detect and discover. Although many pipelines are available for plant virus discovery, all share a common backbone. A description of the process of plant virus detection and discovery from HTS data are presented, providing a summary of the different pipelines available for scientists' utility in their research.

Most studies involving determination of host range, symptom expression and mode of transmission are carried out using crdue virus obtained from an infected plant. Virus purification is undertaken with the objectives of obtaining virus preparations of both high quality and good yield. In identifying an unknown virus, the usual process involves the stepwise determination of as many characters as may be required to match the information about an unknown virus with that of a known, previously-described virus. Plant virologists recognize that there is no universally applicable set of characters for defining virus species. Some carlaviruses occur in relatively high concentrations in their natural or experimental host and have been readily purified. Accurate diagnosis often depends on a comparison of many distinct properties of the agent. Some of these properties can be determined using crude sap, but in general such properties are capable of providing only a tentative diagnosis, or of assigning the causal virus to a virus Family or Group.

‘Hall’s Beauty’ is a new, early-ripening, high-quality, firm, and sweet thornless trailing blackberry (Rubus subg. Rubus Watson) cultivar with extremely large and attractive double flowers from the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) breeding program in Corvallis, OR, released in cooperation with Oregon State University’s Agricultural Experiment Station. Mr. Harvey Hall (Shekinah Berries Ltd., Pyes Pa, New Zealand), with New Zealand HortResearch, the forerunner of The New Zealand Institute Plant & Food Research, originally incorporated the source of thornlessness used in ‘Hall’s Beauty’ into useful germplasm. The collaborative effort between him and USDA-ARS breeders in exchanging Rubus germplasm was critical to the current success of both programs; the name of the cultivar reflects gratitude for this relationship and Hall’s tremendous contributions, with his spouse Robyn Hall’s support, to blackberry breeding worldwide. ‘Hall’s Beauty’ is introduced as a machine harvestable, high-quality blackberry that has extremely large, attractive, and ornamental double flowers, which havemanymore petals than typical blackberries and that produce large, well-formed berries for the fresh or the processed fruit market. ‘Hall’s Beauty’ should be adapted to areas where other trailing blackberries can be grown successfully. AU.S. Plant Patent has been applied for (USPPAF 15/330,950).

new ornamental blueberry (Vaccinium hybrid) that is targeted toward the home gardener and ornamental landscape trade.