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

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.

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 252-258 ◽  
Author(s):  
Sh. Farzadfar ◽  
R. Pourrahim ◽  
A. R. Golnaraghi ◽  
A. Ahoonmanesh

The main areas for field-grown sugar beet (Beta vulgaris) production in Iran were surveyed to study the occurrence and incidence of Alfalfa mosaic virus (AlMV), Beet curly top virus (BCTV), Beet mosaic virus (BtMV), Beet western yellows virus (BWYV), Beet yellows virus (BYV), Chickpea chlorotic dwarf virus (CpCDV), Cucumber mosaic virus (CMV), and Turnip mosaic virus (TuMV) during the growing season of 2001. A total of 5,292 random leaf samples in addition to 1,294 symptomatic leaves were collected from nine commercial sugar beet growing provinces of Iran and tested by tissue-blot immunoassay (TBIA). Serological diagnoses were confirmed by electron microscopy and host range studies. The highest virus incidence among the surveyed provinces was recorded in Qazvin, followed by Fars, Esfahan, Azarbayejan-e-gharbi, Khorasan, Kermanshah, Semnan, and Hamedan. According to the TBIA results, viruses in decreasing order of incidence in sugar beet were BCTV (27.9%), followed by BWYV (17.4%), CpCDV (12.5%), BYV (10.6%), BtMV (7.4%), TuMV (2.9%), AlMV (1.3%), and CMV (1.2%). Nearly 35% of sugar beets in Iran were infected by one or both of the two leafhopper-transmitted viruses (BCTV and CpCDV). Moreover, about 28% were infected by at least one of the six aphid-transmitted viruses (AlMV, BWYV, BtMV, BYV, CMV, and TuMV). Overall, one or more of the eight viruses assayed were detected in 45.5% of the plants surveyed. Several plants (35%) displaying virus-like symptoms did not react with the virus antisera used, suggesting that more viruses or virus-like agents are infecting sugar beets in Iran. In reference to the earlier reports, this is the first report of AlMV and TuMV in sugar beet fields of Iran. Also, this is the first detection of CpCDV as a pathogen of sugar beet.


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 ◽  
...  

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.


2003 ◽  
Vol 93 (4) ◽  
pp. 478-484 ◽  
Author(s):  
Maria J. Soto ◽  
Robert L. Gilbertson

A polymerase chain reaction (PCR)-based method for the detection of the curtovirus Beet mild curly top virus (BMCTV, previously named the Worland strain of Beet curly top virus) was developed and used to investigate the BMCTV-beet leafhopper interaction. Using PCR and a BMCTV-specific primer pair, an ≈1.1-kb BMCTV DNA fragment was amplified from adult leafhoppers and from the organs involved in circulative transmission: the digestive tract, hemolymph, and salivary glands. The temporal distribution of BMCTV in the leafhopper was determined using insects given acquisition access periods (AAPs) ranging from 1 to 48 h on BMCTV-infected shepherd's purse plants. BMCTV was detected in the digestive tract after all AAPs, in the hemolymph after AAPs of 3 h or greater, and in the salivary glands after AAPs of 4 h or greater. The amount of virus detected in the hemolymph and salivary glands increased with AAP length. The virus persisted for up to 30 days in leafhoppers (given a 3-day AAP on BMCTV-infected plants) maintained on corn plants, a nonhost for BMCTV, but transovarial transmission was not detected. These results are consistent with a persistent but nonpropagative mode of circulative transmission.


Plant Disease ◽  
2013 ◽  
Vol 97 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Carl A. Strausbaugh ◽  
Imad A. Eujayl ◽  
Paul Foote

The Rhizoctonia-bacterial root rot complex continues to be a concerning problem in sugar beet production areas. To investigate resistance to this complex in 26 commercial sugar beet cultivars, field studies and greenhouse studies with mature roots from the field were conducted with Rhizoctonia solani anastomosis group 2-2 IIIB strains and Leuconostoc mesenteroides. Based on means for the 26 cultivars in the 2010 and 2011 field studies, fungal rot ranged from 0 to 8%, bacterial rot ranged from 0 to 37%, total internal rot ranged from 0 to 44%, and surface rot ranged from 0 to 52%. All four rot variables resulted in significant (P < 0.0001) cultivar differences. Based on regression analysis, strong positive relationships (r2 from 0.6628 to 0.9320; P < 0.0001) were present among the rot variables. When ranking cultivars, the most consistent rot variable was surface rot, because 12 of 13 variable–year combinations had significant (P ≤ 0.05) correlations. When cultivar ranking in greenhouse assays was compared, there was frequently a positive correlation with storage data but no relationship with field results. Thus, the greenhouse assays will identify storage rot resistance but field screening will be required to find resistance to this rot complex in the field.


Plant Disease ◽  
2014 ◽  
Vol 98 (8) ◽  
pp. 1075-1080 ◽  
Author(s):  
Carl A. Strausbaugh ◽  
Erik J. Wenninger ◽  
Imad A. Eujayl

Curly top in sugar beet is a serious problem that is caused by Beet curly top virus and other closely related species and transmitted by the beet leafhopper. In order to find a means of reducing curly top in sugar beet, 15 combinations of insecticide seed (Poncho, Poncho Beta, and Poncho Votivo) and foliar (Asana, Cyazypyr, Lorsban, Mustang, Scorpion, and Sivanto) treatments were evaluated versus an untreated check during the 2012 and 2013 growing seasons. An epiphytotic was created by releasing viruliferous beet leafhoppers 58 to 59 days after planting. The foliar sprays were applied 6 to 7 days before and again 6 to 8 days after leafhopper release. Seed treatments (active ingredient: clothianidin) were able to reduce symptoms by 26 to 42% and increase recoverable sucrose by 16 to 21%. The pyrethroids Asana and Mustang also performed well by reducing symptoms 22 to 56% and increasing yields 13 to 20%. The neonicotinoid seed treatments should be an effective way of supplementing host resistance for early-season (at least 59 days after planting) curly top control in sugar beet. The pyrethroid foliar applications could be used to extend curly top control during the midseason period and provide resistance management.


2019 ◽  
pp. 89-92
Author(s):  
Martijn van Overveld ◽  
Martijn Leijdekkers ◽  
Noud van Swaaij

Different seed storage methods, varying in storage temperature, moisture and/or oxygen content, were applied to commercial sugar beet seed lots from four breeding companies. After storage for 10–11 months, germination of the seed was tested in the laboratory (cold test, 10°C). In addition, the contents of active ingredients (fungicides and insecticide) were analyzed and compared with the initial contents before storage. Based on these results, a selection of the most promising storage methods was made to test plant emergence in a field experiment. This research was performed in 2015/16 and in 2016/17. In both years, two storage treatments outperformed the others: these were storage in a closed jar with the addition of moisture absorber (i.e. silica gel) at room temperature and storage at –18°C in a closed plastic bag. Using these two storage methods, seed vigour and contents of active ingredients were comparable to those in seed that had not been stored for one year. Based on the results from this study, the advice to growers for a successful storage of residual sugar beet seed was adjusted in 2017, after including some practical guidelines and considerations.


2018 ◽  
pp. 639-647 ◽  
Author(s):  
Christa Hoffmann

Harvest quality of sugar beet varies according to soil conditions, harvester type and setting, and variety, too. Harvest quality may affect storage losses, in particular when injuries occur. To determine the harvest quality of commercial sugar beet and to quantify resulting storage losses, 92 commercial sugar beet clamps were sampled across Germany and information about harvest conditions were gathered. At IfZ, soil tare, leaf residues, topping diameter, root tip breakage and surface damage of the beets were determined. The beets were stored in 6 replicates in a climate container at 9°C for 10 weeks. The results demonstrate a rather good harvesting quality of sugar beet in Germany. Soil moisture at harvest did not affect harvest quality and storage losses. Very light, but also heavier soils lead to inferior harvest quality (soil tare, root tip breakage, damage) and slightly higher storage losses compared to the typical loam soils. Significant differences occurred between the three harvester types (companies). In general, high root tip breakage and severe surface damage of the beet was related to a high infestation with mould and rots, high invert sugar contents after storage and high sugar losses. Out of the five most planted varieties, in particular one turned out to be very susceptible to damage, resulting in high storage losses. The factor analysis suggests that the effect of harvester / harvester setting and of variety is more important for harvest quality and storage losses of sugar beet than soil conditions at harvest. Therefore, attention should be paid to optimize these conditions.


2021 ◽  
Vol 23 (2) ◽  
pp. 103-109
Author(s):  
Lynda M. Warren

In January 2021 the UK government granted an application for authorisation to use thiamethoxam, a neonicotinoid pesticide, to protect commercial sugar beet crops from attack by viruses transmitted by aphids. This was the first time such an authorisation had been granted in the United Kingdom (UK) and there were concerns that it signalled a weakening of environmental standards now that the UK was no longer part of the European Union. In fact, similar authorisations had been granted by several European Member States in the last 2 years, despite the ban on the use of neonicotinoids introduced in 2018. Nevertheless, the reasons for granting the authorisation do suggest that the balance between adopting a precautionary approach to environmental protection and taking emergency action to protect economic interests may have shifted. It was acknowledged that the proposed mitigation to safeguard bees and other wildlife was not entirely satisfactory. In the end, due to unforeseen weather conditions it meant that the pesticide is not necessary, which in itself demonstrates that short-term emergency measures are unsuitable for dealing with the problem. If the sugar beet industry is to continue to prosper in the UK, it will need to be managed in a way that provides resistance to virus infection without the use of controversial chemicals.


2004 ◽  
Vol 133 (1) ◽  
pp. 41-47 ◽  
Author(s):  
C. I. GALLIMORE ◽  
C. PIPKIN ◽  
H. SHRIMPTON ◽  
A. D. GREEN ◽  
Y. PICKFORD ◽  
...  

An outbreak of acute gastroenteritis of suspected viral aetiology occurred in April 2003 in the British Royal Fleet Auxillary ship (RFA) Argus deployed in the Northern Arabian Gulf. There were 37 cases amongst a crew of 400 personnel. Of 13 samples examined from cases amongst the crew, six enteric viruses were detected by reverse transcriptase polymerase chain reaction (RT–PCR). Five different viruses were identified including, three norovirus genotypes, a sapovirus and a rotavirus. No multiple infections were detected. A common food source was implicated in the outbreak and epidemiological analysis showed a statistically significant association with salad as the source of the outbreak, with a relative risk of 3·41 (95% confidence interval of 1·7–6·81) of eating salad on a particular date prior to the onset of symptoms. Faecal contamination of the salad at source was the most probable explanation for the diversity of viruses detected and characterized.


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