Epidemiology and Genetic Diversity of Grapevine Leafroll-Associated Viruses in British Columbia

Grapevine leafroll disease (GLD) is a complex associated with one or more virus species belonging to the family Closteroviridae. The majority of viruses in this complex are vectored by one or more species of mealybugs (Pseudococcidae) and/or scale insects (Coccidae). Grape-growing regions of British Columbia (BC), including Okanagan, Similkameen, and Fraser valleys and Kamloops (BC central interior), Vancouver, and Gulf islands, were surveyed during the 2014 and 2015 growing seasons for the presence of four major grapevine leafroll-associated viruses, including Grapevine leafroll-associated virus 1 (GLRaV-1), GLRaV-2, GLRaV-3, and GLRaV-4. In total, 3,056 composite five-vine samples were collected from 153 Vitis vinifera and three interspecific hybrid vineyard blocks. The results showed GLRaV-3 to be the most widespread, occurring in 16.7% of the composite samples, followed by GLRaV-4 (3.9%), GLRaV-1 (3.8%), and GLRaV-2 (3.0%). Mixed infections of two or more GLRaVs were found in 4.1% of the total samples. The relative incidence of GLRaVs differed among regions and vineyard blocks of a different age. Characterization of partial CO1 region from a total of 241 insect specimens revealed the presence of Pseudococcus maritimus, Parthenolecanium corni, and other Pulvinaria sp. in BC vineyards. Spatial patterns of GLRaV-3 infected grapevines in three vineyard blocks from three different regions in the Okanagan Valley showed variable degrees of increase in disease spread ranging from 0 to 19.4% over three growing seasons. Regional differences in the relative incidence and spread of GLD underline the need for region-based management programs for BC vineyards.

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Mealybug Transmission of Grapevine Leafroll Viruses: An Analysis of Virus–Vector Specificity

Phytopathology ◽

10.1094/phyto-100-8-0830 ◽

2010 ◽

Vol 100 (8) ◽

pp. 830-834 ◽

Cited By ~ 77

Author(s):

Chi-Wei Tsai ◽

Adib Rowhani ◽

Deborah A. Golino ◽

Kent M. Daane ◽

Rodrigo P. P. Almeida

Keyword(s):

Plant Pathogens ◽

Phylogenetic Analyses ◽

Virus Vector ◽

Disease Spread ◽

Virus Species ◽

Vector Species ◽

Vector Transmission ◽

Planococcus Ficus ◽

Grapevine Leafroll Disease ◽

Leafroll Disease

To understand ecological factors mediating the spread of insect-borne plant pathogens, vector species for these pathogens need to be identified. Grapevine leafroll disease is caused by a complex of phylogenetically related closteroviruses, some of which are transmitted by insect vectors; however, the specificities of these complex virus–vector interactions are poorly understood thus far. Through biological assays and phylogenetic analyses, we studied the role of vector-pathogen specificity in the transmission of several grapevine leafroll-associated viruses (GLRaVs) by their mealybug vectors. Using plants with multiple virus infections, several virus species were screened for vector transmission by the mealybug species Planococcus ficus and Pseudococcus longispinus. We report that two GLRaVs (-4 and -9), for which no vector transmission evidence was available, are mealybug-borne. The analyses performed indicated no evidence of mealybug–GLRaV specificity; for example, different vector species transmitted GLRaV-3 and one vector species, Planococcus ficus, transmitted five GLRaVs. Based on available data, there is no compelling evidence of vector–virus specificity in the mealybug transmission of GLRaVs. However, more studies aimed at increasing the number of mealybug species tested as vectors of different GLRaVs are necessary. This is especially important given the increasing importance of grapevine leafroll disease spread by mealybugs in vineyards worldwide.

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Identification of mealybugs, soft scale insects and their predators in vineyards across the savannah agro-ecological region of Nigeria

Zoologist (The) ◽

10.4314/tzool.v18i1.5 ◽

2021 ◽

Vol 18 (1) ◽

pp. 27-32

Author(s):

A.M. Zongoma ◽

D.B. Dangora ◽

M. Sétamou ◽

M.D. Alegbejo ◽

O.J. Alabi

Keyword(s):

Natural Enemies ◽

Integrated Management ◽

Scale Insects ◽

Disease Spread ◽

Universal Primers ◽

Grapevine Virus ◽

Maconellicoccus Hirsutus ◽

Anagyrus Kamali ◽

Leafroll Disease ◽

Ecological Region

Insect-vectored viruses are a major threat to grapevine production but there is a dearth of information on the occurrence and distribution of key grapevine pests in Nigeria. The recent detection of grapevine leafroll associated virus-1 (GLRaV-1), a known insect-vectored ampelovirus, in Nigeria elevates the importance of the identification of its potential vectors as a precursor to assessing the risk of grapevine leafroll disease spread. This study was conducted to determine the occurrence and diversity of potential vectors of grapevine viruses and their natural enemies in vineyards across the savannah agro-ecological region of Nigeria. Forty vineyard and nursery locations were surveyed during 2016 and 45 arthropod samples were collected. The samples were first morphologically identified, and DNA barcoding was conducted on a subset of 16 representative samples using universal primers specific to the Mitochondrial Cytochrome Oxidase subunit I (mtCOI) gene of most insects. The results indicated the presence of two species of scale insects (Parasaissetia nigra and Saissetia coffeae) and two mealybug species (Maconellicoccus hirsutus and Ferrisia virgata), some ofwhich are potential grapevine virus vectors, in Nigerian vineyards. In addition, the natural enemies of these insect species were detected which includes three species of parasitoids (Anagyrus kamali, Anagyrus pseudococci and Encarsia inaron) and one predator (Hyperaspidius mimus). While the detection of mealybugs and scale insects underscore the risk of vector-mediated virus spread in Nigerian vineyards, the identification of their natural enemies indicates presence of natural biological control agents to facilitate an integrated management of economically important grapevine virus diseases in the country. Keywords: Mealybugs; scale insects; parasitoids and predators; insect vectors; grapevine viruses.

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Characterization of Soybean yellow shoot virus, a New Member of the Family Potyviridae Infecting Soybean Plants in Brazil

Plant Disease ◽

10.1094/pdis-06-18-1067-re ◽

2019 ◽

Vol 103 (6) ◽

pp. 1172-1180 ◽

Cited By ~ 1

Author(s):

Antonia dos Reis Figueira ◽

Priscilla S. Geraldino-Duarte ◽

Andrés Mauricio Pinzón Nuñez ◽

Jan van Lent ◽

Suellen B. F. Galvino-Costa ◽

...

Keyword(s):

Amino Acid Sequence Identity ◽

Aphis Gossypii ◽

Seed Transmission ◽

Aphid Transmission ◽

Virus Species ◽

Cytoplasmic Inclusions ◽

Virus Particles ◽

The Family ◽

Soybean Plants

A new virus species, belonging to the family Potyviridae and capable of infecting most of the soybean cultivars grown in Brazil, was collected in Lavras, Minas Gerais, Brazil, and named Soybean yellow shoot virus (SoyYSV). In this study, the complete 9,052-nucleotide genome of SoyYSV was determined and the structural, biological, and molecular properties of the virus were investigated. The SoyYSV genome encoded a single polyprotein that could be subsequently cleaved, generating 11 proteins. The SoyYSV genome shared 49% nucleotide and 36% amino acid sequence identity with Blackberry virus Y. However, the P1 protein of SoyYSV was much smaller and lacked the ALK1 domain characteristic of the genus Brambyvirus. Electron microscopy revealed flexuous filamentous virus particles, 760 to 780 nm in length, and cytoplasmic inclusions typical of those found in plant cells infected with Potyviridae species. In addition to soybean, SoyYSV infected species in the Amaranthaceae, Caricaceae, Fabaceae, and Solanaceae families. Among the most common potyviruses present in Brazil, only SoyYSV induced local necrotic lesions in Carica papaya L. SoyYSV was transmissible by Myzus persicae and Aphis gossypii but lacked the HC-Pro domain required for aphid transmission in other potyviruses. No seed transmission in soybean was observed.

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Full genome characterization of Laem Singh virus (LSNV) in shrimp Penaeus monodon

10.1101/2020.07.25.221432 ◽

2020 ◽

Author(s):

Suparat Taengchaiyaphum ◽

Jiraporn Srisala ◽

Piyachat Sanguanrut ◽

Chalermporn Ongvarrasopone ◽

Timothy W. Flegel ◽

...

Keyword(s):

Penaeus Monodon ◽

Plant Viruses ◽

Virus Species ◽

Full Genome ◽

Cloning And Sequencing ◽

Genome Characterization ◽

Sequence Identity ◽

The Family ◽

Shrimp Virus

ABSTRACTLaem Singh virus (LSNV) was discovered in 2006 and proposed as a necessary but insufficient cause of retarded growth in the giant tiger shrimp Penaeus monodon. Its closest relatives were plant viruses including an unassigned Sobemovirus and viruses in the family Luteoviridae. During succeeding years, attempts to obtain the full LSNV genome sequence by genome walking failed. However, recent publication of the full sequence of Wenzhou shrimp virus 9 (WZSV 9) at GenBank revealed that LSNV sequences in our database shared 99% sequence identity with it. Thus, we hypothesized that LSNV and WZSV 9 were different isolates of the same virus species. Here we confirm that hypothesis by cloning and sequencing of the full genome of LSNV from P. monodon and by showing that it consists of two fragments each with 99% identity to the matching fragments of WZSV.

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Heritability estimates for height for young interior spruce in British Columbia

Canadian Journal of Forest Research ◽

10.1139/x88-025 ◽

1988 ◽

Vol 18 (2) ◽

pp. 158-162 ◽

Cited By ~ 10

Author(s):

G. Kiss ◽

F.C. Yeh

Keyword(s):

British Columbia ◽

Major Influence ◽

Narrow Sense Heritability ◽

North Central ◽

Growing Seasons ◽

The Family ◽

Interior Spruce ◽

Good Site ◽

Heritability Estimates ◽

Brush Control

Height growth for interior spruce (Piceaglauca (Moench) Voss and P. engelmannii Parry) after 3, 6, and 10 growing seasons was assessed in a progeny test of 174 wind-pollinated families at three test sites in north central British Columbia. Test sites had a major influence on the juvenile growth of interior spruce, reflecting differences in potential site productivity as well as the importance of good site preparation and subsequent brush control for spruce seedlings. Mean heights within and across sites differed among families. The 3- and 6-year family performances correlated with family performances at age 10. Family–site interaction was significant at the 1% probability level, but accounted for no more than a quarter of the family variance at the three assessment years. Performance of the top and bottom 25% of families was consistent across the three sites. The narrow-sense heritability estimates after the third, sixth, and tenth growing seasons were 0.52, 0.36, and 0.29, respectively. The corresponding family heritability estimates were 0.82, 0.73, and 0.67, respectively.

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Processing and characterization of YBa2Cu3O7−x/Ag composites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173364 ◽

1990 ◽

Vol 48 (4) ◽

pp. 46-47

Author(s):

Jafar Javadpour ◽

Bradley L. Thiel ◽

Sarikaya Mehmet ◽

Ilhan A. Aksay

Keyword(s):

Composite System ◽

Precursor Solution ◽

Microstructural Development ◽

Superconducting Properties ◽

Practical Applications ◽

Nitrate Precursor ◽

Cold Pressed ◽

Tape Cast ◽

Composite Samples

Practical applications of bulk YBa2Cu3O7−x materials have been limited because of their inadequate critical current density (jc) and poor mechanical properties. Several recent reports have indicated that the addition of Ag to the YBa2Cu3O7−x system is beneficial in improving both mechanical and superconducting properties. However, detailed studies concerning the effect of Ag on the microstructural development of the cermet system have been lacking. Here, we present some observations on the microstructural evolution in the YBa2Cu3O7−x/Ag composite system.The composite samples were prepared by mixing various amounts (2.5 - 50 wt%) AgNO3 in the YBa2Cu3O7−x nitrate precursor solution. These solutions were then spray dried and the resulting powders were either cold pressed or tape cast. The microstructures of the sintered samples were analyzed using SEM (Philips 515) and an analytical TEM (Philips 430T).The SEM micrographs of the compacts with 2.5 and 50 wt% Ag addition sintered at 915°C (below the melting point of Ag) for 1 h in air are displayed in Figs. 1 and 2, respectively.

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Prothrombin Metz : Purification and Characterization of a Variant of Human Prothrombin

10.1055/s-0038-1665670 ◽

1979 ◽

Author(s):

M Ribieto ◽

J Elion ◽

D Labie ◽

F Josso

Keyword(s):

Molecular Weight ◽

Gel Electrophoresis ◽

Polyacrylamide Gel Electrophoresis ◽

Factor Xa ◽

Polyacrylamide Gel ◽

Cleavage Pattern ◽

Purification And Characterization ◽

Double Immunodiffusion ◽

The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.

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