scholarly journals Characterization of Beet curly top virus Strains Circulating in Beet Leafhoppers (Hemiptera: Cicadellidae) in Northeastern Oregon

Plant Disease ◽  
2016 ◽  
Vol 100 (8) ◽  
pp. 1586-1590 ◽  
Author(s):  
Silvia I. Rondon ◽  
Mary Sue Roster ◽  
Launa L. Hamlin ◽  
Kelsie J. Green ◽  
Alexander V. Karasev ◽  
...  
Keyword(s):  
Genomic Sequence ◽  
Beet Leafhopper ◽  
Beet Curly Top Virus ◽  
Circulifer Tenellus ◽  
Virus Incidence ◽  
Important Pest ◽  
Important Field ◽  
Virus Genomes ◽  
Virus Strains

The beet leafhopper, Circulifer tenellus, is an agriculturally important pest, particularly in the western United States. This insect transmits the Beet curly top virus (BCTV) to multiple crops, including bean, tomato, and pepper. In this study, we investigated the incidence of BCTV in individual leafhoppers collected at several sites in northeastern Oregon during the growing season in 2007, 2008, and 2009. Of the 800 insects tested, 151 (18.9%) were found positive for the virus. Percentage of virus incidence varied from 0% at one location in 2009 to a high of 55.6% for a location sampled in 2008. The complete virus genomes from one virus-positive insect collected in each of the 3 years were determined. BLAST analysis of the BCTV whole-genome sequences from 2007, 2008, and 2009 insects showed 98, 94, and 96% identities with the BCTV-Worland sequence (AY134867), respectively. The BCTV_2008 sequence showed the greatest identity (96%) with another BCTV genomic sequence (JN817383), and was found to be a recombinant between the BCTV-Worland type, representing the majority of the genome (approximately 2.2 kb), and the BCTV-CFH type that provided an approximately 0.8-kb fragment spanning replication-related genes C1 and C2. This area of the BCTV genome, between the C1 and C2 genes, was previously found to carry symptom determinants of the virus, and the data may suggest more severe effects of BCTV during the 2008 season. Results indicate that BCTV is common and widespread in C. tenellus in eastern Oregon and that there is substantial genetic diversity among the virus strains present in this important field and vegetable crop-growing region.

scholarly journals Prediction of Early Season Beet Leafhopper Populations in Southern New Mexico

2020 ◽  
Vol 21 (1) ◽  
pp. 71-76
Author(s):  
Erik Lehnhoff ◽  
Rebecca Creamer
Keyword(s):  
New Mexico ◽  
Weed Management ◽  
Broad Host Range ◽  
Insect Vector ◽  
Early Season ◽  
Beet Leafhopper ◽  
Beet Curly Top Virus ◽  
Circulifer Tenellus ◽  
Sisymbrium Irio ◽  
The Relationship

Curly top is an important widespread disease in semiarid regions that can be caused by several Curtovirus and Becurtovirus species. The strains of beet curly top virus (BCTV) have been some of the most widely reported to be associated with curly top. The viruses causing curly top are phloem limited and transmitted by the beet leafhopper (BLH), Circulifer tenellus Baker (Hemiptera: Cicadellidae). The BLH can also transmit other important pathogens such as phytoplasmas. Both the virus and insect vector have a broad host range of crops and weeds, including the winter annual weed London rocket (Sisymbrium irio L.). Prior prediction of disease would allow growers a window of opportunity to make informed management choices. A prediction model of BLH abundance was developed for southern New Mexico based on fall precipitation, which corresponds with London rocket emergence, and BLH sticky trap catch data for 2001 to 2018. Regression analyses showed positive associations between BLH numbers and October + November rainfall (P < 0.001) for two areas within southern New Mexico. A third area, where good weed management was used, had lower BLH numbers, and the relationship with precipitation was not significant (P = 0.190). Cumulative-season BLH abundance was correlated with BLH abundance in late April (r = 0.43) and late May (r = 0.56), indicating that early season knowledge of BLH abundance is useful for planning later season management. Although models based on October + November precipitation are good predictors of BLH abundance through June, they may not predict year-long BLH abundance because other environmental and biological factors contribute to subsequent BLH success and movement.

scholarly journals Systemic Insecticides and Plant Age Affect Beet Curly Top Virus Transmission to Selected Host Plants

Plant Disease ◽  
1999 ◽  
Vol 83 (4) ◽  
pp. 351-355 ◽  
Author(s):  
Heping Wang ◽  
P. de A. Gurusinghe ◽  
Bryce W. Falk
Keyword(s):  
Virus Transmission ◽  
Control Program ◽  
Field Studies ◽  
Plant Age ◽  
Sugar Beets ◽  
Susceptibility To Infection ◽  
Beet Leafhopper ◽  
Beet Curly Top Virus ◽  
Circulifer Tenellus ◽  
Systemic Insecticides

Greenhouse and field studies were conducted to assess the effects of systemic insecticides and plant age on beet curly top virus (BCTV) transmission to sugar beet, tomato, pepper, melon, and cowpea. Sugar beets were the most susceptible to BCTV infection. For all BCTV-susceptible plants tested, younger plants showed greater susceptibility to infection than did older plants, even when inoculations were delayed by only 1 week. Systemic insecticides applied to test plants resulted in increased beet leafhopper (Circulifer tenellus) mortality and decreased the percent BCTV transmission. Soil treatment with imidacloprid (250 g a.i./ha) gave significantly better reductions in BCTV transmission than did dimethoate foliar sprays (280 g a.i./ha). These data suggest that the use of specific systemic insecticides only when crop plants are most susceptible to BCTV infection could be an effective alternative component of the curly top disease control program.

Planting date affects phenology of London rocket (Sisymbrium irio) and interaction with beet leafhopper (Circulifer tenellus)

Weed Science ◽  
2006 ◽  
Vol 54 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Jarren Ray ◽  
Jill Schroeder ◽  
Rebecca Creamer ◽  
Leigh Murray
Keyword(s):  
New Mexico ◽  
Field Experiments ◽  
Insect Vector ◽  
Planting Dates ◽  
Beet Leafhopper ◽  
Beet Curly Top Virus ◽  
Circulifer Tenellus ◽  
Plant Emergence ◽  
Sisymbrium Irio ◽  
The Impact

London rocket is a common winter annual weed in southern New Mexico that can host beet curly top virus and its insect vector, the beet leafhopper. Experiments were conducted in southern New Mexico to determine if London rocket could serve as a host for overwintering beet leafhopper. Field experiments were carried out from 2002 to 2003 and from 2003 to 2004 to compare the impact of three London rocket planting dates on plant emergence and life history and leafhopper survival. Emergence was highest in October-planted London rocket, low in January/February plantings, and did not occur for August plantings. The life cycle was 185 d and 125 d for October- and January-planted London rocket, respectively, and growth of the plant (including height and rosette base diameter) was greater for London rocket that was planted in October. October-planted London rocket survived from late October through mid to late April, the period of time needed to serve as an overwintering host for beet leafhoppers. Caging the plants to assess beet leafhopper survival did not affect rate of plant growth, but it reduced the time to flowering for October-planted London rocket and increased the height and weight of plants. Beet leafhoppers were able to survive for approximately 2 mo in early winter or spring on caged London rocket plants.

Molecular characterization of Spiroplasma citri BR3 lines that differ in transmissibility by the leafhopper Circulifer tenellus

1996 ◽  
Vol 42 (2) ◽  
pp. 124-131 ◽  
Author(s):  
Jacqueline Fletcher ◽  
Mary E. Shaw ◽  
Ginger R. Baker ◽  
Karla J. Dugan ◽  
Fengchun Ye ◽  
...  
Keyword(s):  
Extrachromosomal Dna ◽  
Protein Patterns ◽  
Spiroplasma Citri ◽  
Dual Mobility ◽  
Beet Leafhopper ◽  
Circulifer Tenellus ◽  
Unique Restriction ◽  
Total Dna ◽  
Dna Profiles

Four lines of Spiroplasma citri strain BR3, derived from different maintenance conditions over several years and differing in their ability to be transmitted by the beet leafhopper Circulifer tenellus were characterized. The lines included BR3-T (transmissible), maintained in turnip by leafhopper transmission; BR3-G (now nontransmissible), maintained in plants by periodic graft transmission; BR3-P (now rarely transmissible), subcultured in artificial medium over 130 times; and BR3-M (transmissible), subcultured 43 times. Although all four lines had similar overall protein profiles, the two transmissible lines each contained two proteins missing in the non- or rarely transmitted lines. In addition, one protein was unique to BR3-M and another was unique to BR3-P. Spiralin, a major S. citri membrane protein, had dual mobility in line BR3-G only. Patterns of extrachromosomal DNA and restricted total DNA also were similar, although differences occurred among the four lines. The genome of line BR3-G was larger than those of the other lines and unique restriction bands occurred in this line. Protein and DNA profiles of six to eight individual clones of each line also were compared. Protein patterns within each clone were indistinguishable except for a difference in the migration rate of spiralin in clones of BR3-G. Restricted total DNA showed differential patterns among clones of each line, possibly reflecting differences in extrachromosomal DNA. Molecular differences among the spiroplasma lines may reflect the selection pressures of the different environments in which they were maintained and suggest genes and proteins that may be involved in the biological phenotypes of these lines.Key words: spiroplasma, Mollicutes, insect transmission.

scholarly journals Beet curly top virus Strains Associated with Sugar Beet in Idaho, Oregon, and a Western U.S. Collection

Plant Disease ◽  
2017 ◽  
Vol 101 (8) ◽  
pp. 1373-1382 ◽  
Author(s):  
Carl A. Strausbaugh ◽  
Imad A. Eujayl ◽  
William M. Wintermantel
Keyword(s):  
Sugar Beet ◽  
Mixed Infections ◽  
Beet Leafhopper ◽  
Beet Curly Top Virus ◽  
Primary Means ◽  
Commercial Sugar ◽  
Polymerase Chain ◽  
Production Areas ◽  
Virus Strains ◽  
Contingency Test

Curly top of sugar beet is a serious, yield-limiting disease in semiarid production areas caused by Beet curly top virus (BCTV) and transmitted by the beet leafhopper. One of the primary means of control for BCTV in sugar beet is host resistance but effectiveness of resistance can vary among BCTV strains. Strain prevalence among BCTV populations was last investigated in Idaho and Oregon during a 2006-to-2007 collection but changes in disease severity suggested a need for reevaluation. Therefore, 406 leaf samples symptomatic for curly top were collected from sugar beet plants in commercial sugar beet fields in Idaho and Oregon from 2012 to 2015. DNA was isolated and BCTV strain composition was investigated based on polymerase chain reaction assays with strain-specific primers for the Severe (Svr) and California/Logan (CA/Logan) strains and primers that amplified a group of Worland (Wor)-like strains. The BCTV strain distribution averaged 2% Svr, 30% CA/Logan, and 87% Wor-like (16% had mixed infections), which differed from the previously published 2006-to-2007 collection (87% Svr, 7% CA/Logan, and 60% Wor-like; 59% mixed infections) based on a contingency test (P < 0.0001). Whole-genome sequencing (GenBank accessions KT276895 to KT276920 and KX867015 to KX867057) with overlapping primers found that the Wor-like strains included Wor, Colorado and a previously undescribed strain designated Kimberly1. Results confirm a shift from Svr being one of the dominant BCTV strains in commercial sugar beet fields in 2006 to 2007 to becoming undetectable at times during recent years.

scholarly journals Complete Genome Sequences of Six Measles Virus Strains

2018 ◽  
Vol 6 (13) ◽  
Author(s):  
My V. T. Phan ◽  
Claudia M. E. Schapendonk ◽  
Bas B. Oude Munnink ◽  
Marion P. G. Koopmans ◽  
Rik L. de Swart ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Complete Genome ◽  
Measles Virus ◽  
Genetic Characterization ◽  
Critical Component ◽  
Wild Type ◽  
Genome Sequences ◽  
Virus Strains ◽  
Generation Sequencing

ABSTRACT Genetic characterization of wild-type measles virus (MV) strains is a critical component of measles surveillance and molecular epidemiology. We have obtained complete genome sequences of six MV strains belonging to different genotypes, using random-primed next generation sequencing.

Characterization of beet curly top virus subgenomic DNA localizes sequences required for replication

Virology ◽  
1992 ◽  
Vol 189 (2) ◽  
pp. 808-811 ◽  
Author(s):  
Thomas Frischmuth ◽  
John Stanley
Keyword(s):  
Beet Curly Top Virus
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