scholarly journals Effect of Imidacloprid on Incidence of Tomato yellow leaf curl virus

Plant Disease ◽  
2001 ◽  
Vol 85 (1) ◽  
pp. 84-87 ◽  
Author(s):  
N. E. Ahmed ◽  
H. O. Kanan ◽  
Y. Sugimoto ◽  
Y. Q. Ma ◽  
S. Inanaga
Keyword(s):  
Disease Incidence ◽  
Field Trials ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Tomato Plants ◽  
Stages Of Growth ◽  
Tomato Yield ◽  
The Mean ◽  
Leaf Curl Virus ◽  
Leaf Curl

Confidor, an imidacloprid insecticide, was used in two applications at four rates (47.6, 71.4, 95.2, and 119 g a.i./ha) for indirectly controlling Tomato yellow leaf curl virus (TYLCV) in field plantings of tomato. This spray regimen was compared with standard applications of cypermethrins at 10- to 15-day intervals throughout the growing season. In three field trials, a combination of integrated pest management (IPM) practices and two applications of Confidor at the two highest rates immediately after planting and 6 weeks later, protected tomato plants against the disease until 12 weeks after sowing. All rates of Confidor reduced disease incidence compared with standard chemical control applied in an integrated strategy, and quantitative efficacy increased with increase of insecticide rate. In the three seasons, the mean incidence of TYLCV 12 weeks after sowing was 42.7% in plots not adopting IPM compared with 15.7% in those that did. Disease incidence was reduced by Confidor treatments to 2.2 to 17%. Confidor-treated plots consistently had higher yields than control plots, and the yields decreased with the decrease in the rate of Confidor application. Confidor offers several advantages over standard applications of cypermethrins to control TYLCV. When applied immediately after planting, its long-lasting systemic activity protected the crop against the disease during early stages of growth. In addition, it reduced the number of sprays and increased tomato yield.

scholarly journals First Report of Tomato yellow leaf curl virus on Tomato Crops in Greece

Plant Disease ◽  
2001 ◽  
Vol 85 (6) ◽  
pp. 678-678 ◽  
Author(s):  
A. D. Avgelis ◽  
N. Roditakis ◽  
C. I. Dovas ◽  
N. I. Katis ◽  
C. Varveri ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Rflp Analysis ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Degenerate Primers ◽  
Sequence Comparisons ◽  
Tomato Plants ◽  
First Report ◽  
Leaf Curl Virus ◽  
Leaf Curl

In late summer 2000, tomato (Lycopersicon esculentum Mill.) grown in greenhouses in Ierapetra, Tympaki, and Chania (Crete) showed leaf curling, reduced leaf size, yellowing, shortened internodes, and a bushy appearance. More than 30 ha of tomato greenhouses were affected and the disease incidence ranged from 15 to 60% with estimated crop losses of over $500,000. Similar symptoms were observed in tomato samples from Marathon (Attiki) and Southern Peloponnese. All greenhouses with infected plants were infested with high populations of Bemisia tabaci (Gennadius), which were also observed outside the greenhouses on several weeds. Tomato symptoms were similar to those caused by Tomato yellow leaf curl virus (TYLCV). The assumed virus could not be transmitted mechanically but successful transmission was obtained by grafting onto healthy tomato plants. Over 100 samples of symptomatic tomato plants collected from Crete and southern Peloponnese gave positive reactions when tested by ELISA using monoclonal antibodies to TYLCV-European (Adgen Ltd). The serological results were confirmed by PCR using two pairs of primers, universal degenerate (1) and MA 13 and MA 17 (2), amplifying different parts of the virus genome. The restriction fragment length polymorphism (RFLP) analysis (AluI, HaeIII, and TaqI) of the 541 bp amplicon obtained with the degenerate primers showed patterns similar to TYLCV-Is (Israeli species). The second pair of primers gave the expected 348 bp product, which was sequenced. Sequence comparisons revealed 99% identity with TYLCV-Is (EMBL no. X15656, X76319). The resulting sequence was at least 97.7% identical to sequences of TYLCV isolates from the Dominician Republic (EMBL no. AF024715), Cuba (EMBL no. AJ223505), Portugal (EMBL no. AF105975), Iran (EMBL no. AJ13271), and Spain (EMBL no. AF071228). The disease appeared for the first time in 1992 in Tymbaki, but was limited to very few plants in one glasshouse. However, the cause was not determined. To our knowledge, this is the first report of TYLCV of the Begomovirus genus in Greece. References: (1) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (2) J. Navas-Castillo et al. J. Virol. Methods 75:195, 1998.

Integrated Management of Tomato Yellow Leaf Curl Virus and its Whitefly Vector in Tomato

2019 ◽  
Vol 112 (4) ◽  
pp. 1526-1540 ◽  
Author(s):  
David G Riley ◽  
Rajagopalbabu Srinivasan
Keyword(s):  
Symptom Severity ◽  
Virus Disease ◽  
Disease Incidence ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Virus Family ◽  
Tomato Yield ◽  
Tomato Cultivars ◽  
Leaf Curl Virus ◽  
Leaf Curl

AbstractWhitefly-transmitted Tomato yellow leaf curl virus (Family Geminiviridae; Genus Begomovirus) severely restricts tomato production in the Southeastern United States. Whitefly and tomato yellow leaf curl virus management studies typically investigate control tactics individually, but successful management of this pest complex more often relies on a combination of tactics. This study examined the individual and combined effects of tomato yellow leaf curl virus-resistant cultivars, insecticides, and metallic reflective mulch on whiteflies, tomato yellow leaf curl virus disease incidence, and marketable tomato yields using split-split plot trials over 3 yr. Reflective mulch significantly reduced whitefly adults and nymphs and tomato yellow leaf curl virus symptom severity in all 3 yr of the study. Reflective mulch treatments also provided greater marketable tomato yield in 2 out of 3 yr. Imidacloprid and cyantraniliprole treatments reduced whitefly adults and nymphs’ establishment and marginally increased yields, but there was no significant insecticide effect on tomato yellow leaf curl virus incidence/symptom severity compared with the non-treated check. Virus-resistant tomato cultivars did not influence whitefly populations, but provided consistent reduction in virus disease incidence. Interactions between host plant resistance and insecticide treatments ranged from strongly additive in the standard white plastic mulch treatment to only marginally additive in the reflective mulch treatments in terms of enhancing tomato yields. tomato yellow leaf curl virus-resistant tomato cultivars and reflective mulch provided the bulk of the protection against tomato yellow leaf curl virus disease incidence. However, it was the combination of all the best tactics (reflective mulch, cyantraniliprole, ‘Security’ hyb. tomato yellow leaf curl virus-resistant) that provided the maximum increase in marketable tomato yield (2.8-fold) over the least effective combination (white mulch, no whitefly insecticide, ‘FL47’ hyb. tomato yellow leaf curl virus-susceptible).

scholarly journals First Report of Tomato yellow leaf curl virus in South Carolina

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 379-379 ◽  
Author(s):  
K. S. Ling ◽  
A. M. Simmons ◽  
R. L. Hassell ◽  
A. P. Keinath ◽  
J. E. Polston
Keyword(s):  
South Carolina ◽  
The United States ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Tomato Plants ◽  
First Report ◽  
Pcr Products ◽  
Primer Sequence ◽  
Leaf Curl Virus ◽  
Leaf Curl

Tomato yellow leaf curl virus (TYLCV), a begomovirus in the family Geminiviridae, causes yield losses in tomato (Lycopersicon esculentum Mill.) around the world. During 2005, tomato plants exhibiting TYLCV symptoms were found in several locations in the Charleston, SC area. These locations included a whitefly research greenhouse at the United States Vegetable Laboratory, two commercial tomato fields, and various garden centers. Symptoms included stunting, mottling, and yellowing of leaves. Utilizing the polymerase chain reaction (PCR) and begomovirus degenerate primer set prV324 and prC889 (1), the expected 579-bp amplification product was generated from DNA isolated from symptomatic tomato leaves. Another primer set (KL04-06_TYLCV CP F: 5′GCCGCCG AATTCAAGCTTACTATGTCGAAG; KL04-07_TYLCV CP R: 5′GCCG CCCTTAAGTTCGAAACTCATGATATA), homologous to the Florida isolate of TYLCV (GenBank Accession No. AY530931) was designed to amplify a sequence that contains the entire coat protein gene. These primers amplified the expected 842-bp PCR product from DNA isolated from symptomatic tomato tissues as well as viruliferous whitefly (Bemisia tabaci) adults. Expected PCR products were obtained from eight different samples, including three tomato samples from the greenhouse, two tomato plants from commercial fields, two plants from retail stores, and a sample of 50 whiteflies fed on symptomatic plants. For each primer combination, three PCR products amplified from DNA from symptomatic tomato plants after insect transmission were sequenced and analyzed. All sequences were identical and generated 806 nucleotides after primer sequence trimming (GenBank Accession No. DQ139329). This sequence had 99% nucleotide identity with TYLCV isolates from Florida, the Dominican Republic, Cuba, Guadeloupe, and Puerto Rico. In greenhouse tests with a total of 129 plants in two separate experiments, 100% of the tomato plants became symptomatic as early as 10 days after exposure to whiteflies previously fed on symptomatic plants. A low incidence (<1%) of symptomatic plants was observed in the two commercial tomato fields. In addition, two symptomatic tomato plants obtained from two different retail garden centers tested positive for TYLCV using PCR and both primer sets. Infected plants in both retail garden centers were produced by an out-of-state nursery; this form of “across-state” distribution may be one means of entry of TYLCV into South Carolina. To our knowledge, this is the first report of TYLCV in South Carolina. Reference: (1) S. D. Wyatt and J. K. Brown. Phytopathology 86:1288, 1996.

scholarly journals First Report of TYLCV-IS141, a Tomato Yellow Leaf Curl Virus Recombinant Infecting Tomato Plants Carrying the Ty-1 Resistance Gene in Sardinia (Italy)

Plant Disease ◽  
2019 ◽  
Vol 103 (6) ◽  
pp. 1437-1437 ◽  
Author(s):  
M. Granier ◽  
L. Tomassoli ◽  
A. Manglli ◽  
M. Nannini ◽  
M. Peterschmitt ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Tomato Plants ◽  
First Report ◽  
Virus Recombinant ◽  
Leaf Curl Virus ◽  
Leaf Curl

Whitefly-mediated transmission and subsequent acquisition of highly similar and naturally occurring Tomato yellow leaf curl virus variants

2021 ◽  
Author(s):  
Wendy Marchant ◽  
Saurabh Gautam ◽  
Bhabesh Dutta ◽  
Rajagopalbab Srinivasan
Keyword(s):  
Amino Acids ◽  
Mixed Infection ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Plant Interactions ◽  
Tomato Plants ◽  
Individual Host ◽  
Field Samples ◽  
Leaf Curl Virus ◽  
Leaf Curl

Begomoviruses are whitefly-transmitted viruses that infect many agricultural crops. Numerous reports exist on individual host plants harboring two or more begomoviruses. Mixed infection allows recombination events to occur among begomoviruses. However, very few studies have examined mixed infection of different isolates/variants/strains of a Begomovirus species in hosts. In this study, the frequency of mixed infection of tomato yellow leaf curl virus (TYLCV) variants in field-grown tomato was evaluated. At least 60% of symptomatic field samples were infected with more than one TYLCV variant. These variants differed by a few nucleotides and amino acids resembling a quasispecies. Subsequently, in the greenhouse, single and mixed infection of two TYLCV variants (“variant #2” and “variant #4”) that shared 99.5% nucleotide identity and differed by a few amino acids was examined. Plant-virus variant-whitefly interactions including transmission of one and/or two variants, variants’ concentrations, competition between variants in inoculated tomato plants, and whitefly acquisition of one and/or two variants were assessed. Whiteflies transmitted both variants to tomato plants at similar frequencies; however, the accumulation of variant #4 was greater than variant#2 in tomato plants. Despite differences in variants’ accumulation in inoculated tomato plants, whiteflies acquired variant #2 and variant #4 at similar frequencies. Also, whiteflies acquired greater amounts of TYLCV from singly-infected plants than from mixed-infected plants. These results demonstrated that even highly similar TYLCV variants could differentially influence component (whitefly-variant-plant) interactions.

Interaction between ‘Candidatus Phytoplasma australasiae’ and Tomato yellow leaf curl virus in tomato plants

2020 ◽  
Vol 158 (3) ◽  
pp. 733-744
Author(s):  
Nazanin Ebadi ◽  
Gilda Najafipour ◽  
Mohammad Mehdi Faghihi ◽  
Kavous Ayazpour ◽  
Mohammad Salehi
Keyword(s):  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Tomato Plants ◽  
Leaf Curl Virus ◽  
Leaf Curl

scholarly journals Rate of Tomato yellow leaf curl virus Translocation in the Circulative Transmission Pathway of its Vector, the Whitefly Bemisia tabaci

2001 ◽  
Vol 91 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Murad Ghanim ◽  
Shai Morin ◽  
Henryk Czosnek
Keyword(s):  
Salivary Glands ◽  
Bemisia Tabaci ◽  
Virus Genome ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Tomato Plants ◽  
Hemolymph Sample ◽  
Infected Tomato ◽  
Leaf Curl Virus ◽  
Leaf Curl

Whiteflies (Bemisia tabaci, biotype B) were able to transmit Tomato yellow leaf curl virus (TYLCV) 8 h after they were caged with infected tomato plants. The spread of TYLCV during this latent period was followed in organs thought to be involved in the translocation of the virus in B. tabaci. After increasing acquisition access periods (AAPs) on infected tomato plants, the stylets, the head, the midgut, a hemolymph sample, and the salivary glands dissected from individual insects were subjected to polymerase chain reaction (PCR) without any treatment; the presence of TYLCV was assessed with virus-specific primers. TYLCV DNA was first detected in the head of B. tabaci after a 10-min AAP. The virus was present in the midgut after 40 min and was first detected in the hemolymph after 90 min. TYLCV was found in the salivary glands 5.5 h after it was first detected in the hemolymph. Subjecting the insect organs to immunocapture-PCR showed that the virus capsid protein was in the insect organs at the same time as the virus genome, suggesting that at least some TYLCV translocates as virions. Although females are more efficient as vectors than males, TYLCV was detected in the salivary glands of males and of females after approximately the same AAP.

scholarly journals Tomato curly stunt virus, a New Begomovirus of Tomato Within the Tomato yellow leaf curl virus-IS Cluster in South Africa

Plant Disease ◽  
2000 ◽  
Vol 84 (7) ◽  
pp. 810-810 ◽  
Author(s):  
G. Pietersen ◽  
A. M. Idris ◽  
K. Krüger ◽  
J. K. Brown
Keyword(s):  
South Africa ◽  
Sequence Analysis ◽  
Mosaic Virus ◽  
Tomato Yellow Leaf ◽  
African Cassava Mosaic Virus ◽  
Yellow Leaf ◽  
Tomato Plants ◽  
Leaf Curl Virus ◽  
Cassava Mosaic Virus ◽  
Leaf Curl

Tomato yellow leaf curl virus (TYLCV) causes a serious disease of tomato in many countries throughout the world. Preliminary reports suggested that TYLC disease was present in 1997 in South Africa. In 1998 140 ha of tomato fields in the Onderberg area were assessed for possible presence of TYLCV. Symptoms like those caused by TYLCV isolates in Israel were observed in most fields, and disease incidence ranged from <1 to 50%. Yield losses in individual plants ranged from negligible to 100% and appeared related to the age of the plants at time of infection. Two isolates of the suspect virus were experimentally transmitted from symptomatic tomato to virus-free, glasshouse-grown tomato seedlings by colony. Field and colony whiteflies were identified as the Bemisia tabaci based on mt COI sequence analysis (1). Attempts to transmit the suspect begomovirus by sap inoculation between tomato plants were unsuccessful. Polymerase chain reaction (PCR) amplification with degenerate PCR primers (2) that permit detection of the coat protein gene (AV1) and the common region (CR) of other begomoviruses yielded an amplicon of the expected size (2,100 bp), suggesting begomovirus association with diseased tomato plants. Nucleotide (nt) sequence analysis of AV1 for both tomato isolate AF261885 indicated that they were indistinguishable and shared less than 78% sequence identity with other well-studied begomoviruses, indicating a distinct, previously undescribed begomovirus species. AV1 sequence comparisons also revealed that its closest relatives were members of the TYLCV cluster, which includes South African cassava mosaic virus (77.4%) (AF11785), East African cassava mosaic virus (77.3%) (AJ006459), and TYLCV-IS (76.2%) (X15656). The theoretical Rep binding element in the CR, TCGGT, was identical to TYLCV-IS and Cotton leaf curl virus-Pakistan (AJ002448) (AJ002449). Here, we provisionally designate this new tomato-infecting begomoviral species, Tomato curly stunt virus from South Africa (ToCSV-SA). References: (1) D. R. Frohlich et al. Mol. Ecol. 8:1683, 1999. (2) A. M. Idris and J. K. Brown. Phytopathology 88:648, 1998.

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