scholarly journals North American Grape ‘Norton’ is Resistant to Grapevine Vein Clearing Virus

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2051-2053
Author(s):  
Wenping Qiu ◽  
Sylvia M. Petersen ◽  
Susanne Howard
Keyword(s):  
Powdery Mildew ◽  
North American ◽  
Small Rnas ◽  
Vein Clearing ◽  
Genetic Mechanisms ◽  
Midwest Region ◽  
Vitis Aestivalis ◽  
The U.S ◽  
Vitis Spp ◽  
Grape Cultivars

Grapevines (Vitis spp.) host viruses belonging to 17 families. Virus-associated diseases are a constant challenge to grape production. Genetic resources for breeding virus-resistant grape cultivars are scarce. ‘Norton’ is a hybrid grape of North American Vitis aestivalis and is resistant to powdery mildew and downy mildew. In this study, we assessed resistance of ‘Norton’ to grapevine vein clearing virus (GVCV), which is prevalent in native, wild Vitaceae and in vineyards in the Midwest region of the U.S. We did not detect GVCV in ‘Norton’ as either the scion or the rootstock up to 3 years after it was grafted with a GVCV-infected ‘Chardonel’ grapevine. Upon sequencing of small RNAs, we were able to assemble the GVCV genome from virus small RNAs in GVCV-infected ‘Chardonel’ scion or rootstock, but not from grafted ‘Norton’ scion and rootstock. This study unveils a new trait of ‘Norton’ that can be used in breeding GVCV-resistant grape cultivars, and to investigate genetic mechanisms of ‘Norton’ resistance to GVCV.

scholarly journals Association of a Novel DNA Virus with the Grapevine Vein-Clearing and Vine Decline Syndrome

2011 ◽  
Vol 101 (9) ◽  
pp. 1081-1090 ◽  
Author(s):  
Yu Zhang ◽  
Kashmir Singh ◽  
Ravneet Kaur ◽  
Wenping Qiu
Keyword(s):  
United States ◽  
Small Rnas ◽  
The United States ◽  
Wide Distribution ◽  
Whole Genome Sequence ◽  
Cdna Libraries ◽  
Dna Virus ◽  
Vein Clearing ◽  
Vine Decline ◽  
Midwest Region

A severe vein-clearing and vine decline syndrome has emerged on grapevines (Vitis vinifera) and hybrid grape cultivars in the Midwest region of the United States. The typical symptoms are translucent vein-clearing on young leaves, short internodes and decline of vine vigor. Known viral pathogens of grapevines were not closely associated with the syndrome. To obtain a comprehensive profile of viruses in a diseased grapevine, small RNAs were enriched and two cDNA libraries were constructed from a symptomatic grapevine and a symptomless grapevine, respectively. Deep sequencing of the two cDNA libraries showed that the most abundant viral small RNAs align with the genomes of viruses in the genus Badnavirus, the family Caulimoviridae. Amplification of the viral DNA by polymerase chain reaction allowed the assembly of the whole genome sequence of a grapevine DNA virus, which shared the highest homology with the Badnavirus sequences. This is the first report of a DNA virus in grapevines. The new DNA virus is closely associated with the vein-clearing symptom, and thus has been given a provisional name Grapevine vein clearing virus (GVCV). GVCV was detected in six grapevine cultivars showing vein-clearing and vine decline syndrome in Missouri, Illinois, and Indiana, suggesting its wide distribution in the Midwest region of the United States. Discovery of DNA viruses in grapevines merits further studies on their epidemics and economic impact on grape production worldwide.

Grapevine vein clearing virus is prevalent and genetically variable in grape aphid (Aphis illinoisensis Shimer) populations

Plant Disease ◽  
2020 ◽  
Author(s):  
Adam Uhls ◽  
Sylvia Petersen ◽  
Cory Von Keith ◽  
Susanne Howard ◽  
Xiaokai Bao ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Plant Virus ◽  
The State ◽  
Genetic Composition ◽  
Severe Stunting ◽  
Vein Clearing ◽  
The Usa ◽  
Quantitative Analyses ◽  
Midwest Region ◽  
Vitis Spp

Grapevine vein clearing virus (GVCV) causes severe stunting and death of cultivated grapevines and is prevalent in native Vitis spp. and Ampelopsis cordata in the Midwest region of the USA. GVCV can be transmitted from wild A. cordata to Vitis spp. by grape aphid (Aphis illinoisensis) under greenhouse conditions, but its prevalence, genetic composition and genome number in native grape aphids are unknown. In this study, we collected grape aphids from native Vitaceae across the state of Missouri in 2018 and 2019, and conducted diagnostic, genetic and quantitative analyses. GVCV was detected in 91 (87%) of the 105 randomly sampled communities on 71 Vitaceae plants. It was present in 211 (40%) of 525 single grape aphids. Diverse GVCV variants from aphids were present on both GVCV-negative and -positive plants. Identical GVCV variants were found in grape aphids sampled from wild and cultivated Vitaceae, indicating that viruliferous aphids likely migrate and disperse GVCV variants among wild and cultivated Vitaceae. In addition, we found that the number of GVCV genomes varies largely in the stylet and body of individual aphids. Our study provides a snapshot of GVCV epidemics and genetic structure in its mobile vector and sessile hosts. This presents a good model for studying epidemiology, ecology and evolution of a plant virus.

Too Close for Comfort: Canada, the U.S. Civil Rights Movement, and the North American Colo(u)r Line

2019 ◽  
Vol 3 (3) ◽  
Author(s):  
Asa McKercher
Keyword(s):  
Civil Rights ◽  
Civil Rights Movement ◽  
North American ◽  
The North ◽  
The U.S

Too Close for Comfort: Canada, the U.S. Civil Rights Movement, and the North American Colo(u)r Line

scholarly journals Genetic diversity of table grape based on morphoagronomic traits

2011 ◽  
Vol 68 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Patrícia Coelho de Souza Leão ◽  
Cosme Damião Cruz ◽  
Sérgio Yoshimitsu Motoike
Keyword(s):  
Genetic Diversity ◽  
Clustering Analysis ◽  
Germplasm Collection ◽  
Table Grape ◽  
Cluster Method ◽  
Breeding Programs ◽  
Method Analysis ◽  
Vitis Spp ◽  
Grape Cultivars

The conservation and characterization of grape (Vitis spp) genetic resources in germplasm banks have been the basis of its use in breeding programs that result in development of new cultivars. There are at least 10,000 grape cultivars kept in germplasm collection. The genetic diversity in 136 table grape accessions from the state of Bahia, Brazil, was evaluated. Continuous and discrete morphoagronomic traits were assessed. The clustering analysis by the Tocher otimization method resulted in 30 clusters (considering continuous morphoagronomic traits), and 9 clusters (taking into consideration multicategorical traits). There was no agreement between clusters obtained by both, continuous or discrete phenotypic descriptors, independent of the cluster method analysis used. A satisfactory genetic variability among the table grape accessions was observed.

Gender Gaps in North American Research Productivity: Examining Faculty Publication Rates in Mexico, Canada, and the U.S.

2011 ◽  
Vol 41 (5) ◽  
pp. 649-668 ◽  
Author(s):  
Laura Padilla-Gonzalez ◽  
Amy Scott Metcalfe ◽  
Jesús F. Galaz-Fontes ◽  
Donald Fisher ◽  
Iain Snee
Keyword(s):  
North American ◽  
Research Productivity ◽  
Gender Gaps ◽  
Publication Rates ◽  
American Research ◽  
The U.S

Identification of Resistance to Powdery Mildew in Publicly Available Male Hop Germplasm

2018 ◽  
Vol 19 (3) ◽  
pp. 258-264
Author(s):  
David H. Gent ◽  
Briana J. Claassen ◽  
Megan C. Twomey ◽  
Sierra N. Wolfenbarger
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
Pacific Northwest ◽  
Western United States ◽  
R Genes ◽  
Sources Of Resistance ◽  
Department Of Agriculture ◽  
Breeding Programs ◽  
The Pacific ◽  
The U.S

Powdery mildew (caused by Podosphaera macularis) is one of the most important diseases of hop in the western United States. Strains of the fungus virulent on cultivars possessing the resistance factor termed R6 and the cultivar Cascade have become widespread in the Pacific Northwestern United States, the primary hop producing region in the country, rendering most cultivars grown susceptible to the disease at some level. In an effort to identify potential sources of resistance in extant germplasm, 136 male accessions of hop contained in the U.S. Department of Agriculture collection were screened under controlled conditions. Iterative inoculations with three isolates of P. macularis with varying race identified 23 (16.9%) accessions with apparent resistance to all known races of the pathogen present in the Pacific Northwest. Of the 23 accessions, 12 were resistant when inoculated with three additional isolates obtained from Europe that possess novel virulences. The nature of resistance in these individuals is unclear but does not appear to be based on known R genes. Identification of possible novel sources of resistance to powdery mildew will be useful to hop breeding programs in the western United States and elsewhere.

scholarly journals First Report of Xylella fastidiosa on Catharanthus roseus in Brazil

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 712-712 ◽  
Author(s):  
B. Ueno ◽  
C. K. Funada ◽  
M. A. Yorinori ◽  
R. P. Leite
Keyword(s):  
Catharanthus Roseus ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Glass Slide ◽  
Bacterial Cells ◽  
First Report ◽  
Vein Clearing ◽  
The Media ◽  
Agar Media ◽  
The U.S

In 1998, plants of periwinkle (Catharanthus roseus L.) showing small leaves, short internodes, and dieback symptoms were observed in a garden at the Instituto Agronomico do Parana (IAPAR), Londrina, PR, Brazil. Stems of these plants were cut into short sections and the sap extracted from the tissue by squeezing with pliers. The sap was blotted onto a glass slide and examined for the presence of bacteria by light microscopy (×400). Microscopy observations revealed the presence of a large number of slender, rod-shaped bacterial cells. The bacteria present in the stems of periwinkle were isolated on buffered cysteine-yeast extract (BCYE) and periwinkle wilt (PW) agar media. Stems were disinfected in 70% alcohol and cut into short sections, and the sap extracted as described above. The sap was blotted directly onto the media and the plates were incubated at 28°C. Typical colonies of Xylella fastidiosa were observed 10 days after isolation on both media. Indirect immunofluorescence tests with antibody specific to X. fastidiosa and anti-IgG conjugated with tetrametylrhodamine isothiocyanate (TRITC) were carried out with xylem sap of periwinkle stem and the isolated bacteria. In both cases, immunofluorescence tests were positive for X. fastidiosa. These results confirm that periwinkle plants were infected with X. fastidiosa. This is the first report of the association of X. fastidiosa with periwinkle plants in Brazil. However, the symptoms observed for the X. fastidiosa-infected periwinkle plants differed from those described previously in the U.S. (1): those symptoms consisted of marginal chlorosis and occasional vein clearing of leaves and wilting of the plants. Reference: (1) R. E. McCoy et al. Plant Dis. Rep. 62:1022, 1978.

scholarly journals Trade Creation and Trade Diversion in the North American Free Trade Agreement: The Case of the Agricultural Sector

2007 ◽  
Vol 39 (1) ◽  
pp. 121-134 ◽  
Author(s):  
Dwi Susanto ◽  
C. Parr Rosson ◽  
Flynn J. Adcock
Keyword(s):  
Free Trade ◽  
North American ◽  
Free Trade Agreement ◽  
Agricultural Sector ◽  
Trade Agreement ◽  
Trade Diversion ◽  
The North ◽  
Tariff Rates ◽  
Agricultural Imports ◽  
The U.S

This paper examines the effect of the U.S.-Mexico trade agreement under the North American Free Trade Agreement (NAFTA). The results suggest that U.S. agricultural imports from Mexico have been responsive to tariff rate reductions applied to Mexican products. A one percentage point decrease in tariff rates is associated with an increase in U.S. agricultural imports from Mexico by 5.31% in the first 6 years of NAFTA and by 2.62% in the last 6 years of NAFTA. U.S. imports from Mexico have also been attributable to the pre-NAFTA tariff rates. Overall, the results indicate that the U.S-Mexico trade agreement under NAFTA has been trade creating rather than trade diverting.

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