Population structure of Citrus tristeza virus from field Argentinean isolates

Iglesias, Néstor Gabriel; Gago‐Zachert, Selma; Robledo, Germán; Costa, N. B.; Plata, M. I.; Vera, Osmar Darío; Grau, Oscar; Semorile, Liliana

doi:10.1007/s11262-007-0169-x

Cited by 31 publications

(31 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The average heterozygosity value for our isolates was 0.63. This is almost twice the value calculated for Californian isolates (Kong et al 2000) and similar to the heterozygosity level of the Argentinean isolates (Iglesias et al 2008). High sequence variability among the latter is explained by the high frequency of vector-mediated re-infections and the presence of the most efficient vector Toxoptera citricida (Iglesias et al 2008).…”

supporting

confidence: 74%

“…This is almost twice the value calculated for Californian isolates (Kong et al 2000) and similar to the heterozygosity level of the Argentinean isolates (Iglesias et al 2008). High sequence variability among the latter is explained by the high frequency of vector-mediated re-infections and the presence of the most efficient vector Toxoptera citricida (Iglesias et al 2008). Since no significant rate of vector-mediated CTV transmission has been reported in the East Adriatic region, the only plausible explanation of such high sequence variability in this region may be the high variability among the CTV isolates initially introduced with infected plant material from different citrus-growing countries in the last century, mostly from Japan, former USSR, and Turkey (Gatin 1992;Stamo et al 2000).…”

supporting

confidence: 74%

See 1 more Smart Citation

East Adriatic—a reservoir region of severe Citrus tristeza virus strains

et al. 2009

View full text Add to dashboard Cite

Citrus tristeza virus (CTV) represents one of the major threats to citrus production worldwide. In the East Adriatic region, CTV symptoms are mostly absent due to traditional citrus grafting on trifoliate orange (Poncirus trifoliata), a CTV-tolerant rootstock. Therefore, the virus has been continuously spreading by the propagation of infected material. The genetic variability of CTV was studied on nineteen citrus samples, collected from orchards in the coastal region of Croatia, Montenegro and Albania, that previously tested positive by ELISA and immunocapture RT-PCR. Single-strand conformation polymorphism of the amplified coat protein gene demonstrated the presence of different CTV variants in each amplicon, while sequence analysis of cloned CP gene variants confirmed their clustering into six out of the seven phylogenetic groups so far delineated. Four of these groups include sequences of severe quick decline, seedling yellows and stem-pitting (SP) isolates, thought to be found only rarely in the Mediterranean region. Regardless of the lack of symptoms in the field, CTV isolates from the East Adriatic displayed high genetic variability and pathogenic potential, additionally confirmed by biological characterisation. The high percentage of mixed infections suggest the potential for further diversification and a greater risk of severe variants spreading into new areas.

show abstract

supporting

confidence: 74%

supporting

confidence: 74%

East Adriatic—a reservoir region of severe Citrus tristeza virus strains

et al. 2009

View full text Add to dashboard Cite

show abstract

“…In addition, clustering of the Jamaican isolates within group 1 was observed and is indicative of local virus spread. This was also recently reported with isolates in Cyprus and Argentina (Papayiannis et al 2007;Iglesias et al 2008). The high cp nucleotide similarities between the CTV isolates in Jamaica and other regions suggest a common ancestry (Rubio et al 2001).…”

supporting

confidence: 81%

Detection and characterization of Citrus tristeza virus stem pitting isolates in Jamaica

2009

View full text Add to dashboard Cite

An island wide survey for Citrus tristeza virus (CTV) in citrus orchards across Jamaica (13 regions) was conducted over 2 years. Trees (1, 885) showing virus-like symptoms as well as asymptomatic trees were randomly sampled for testing by ELISA and 55 samples from the 6 major citrus growing regions were graft inoculated on indicator plants. Most samples (74%) reacted to polyclonal antibodies against CTV in ELISA, while 20% were positive in tests using monoclonal antibodies specific to severe CTV strains. Samples collected from the 6 major citrus growing regions produced vein clearing and stem pitting symptoms on Mexican lime indicator plants (87%). In addition, stem pitting symptoms were induced on Duncan grapefruit, sweet orange, sour orange or sweet orange grafted on sour orange. Nucleotide sequencing of the coat protein gene sequences isolated from these samples indicated high identities (88 to 95.5%) among the Jamaican isolates and previously reported stem pitting strains from Central and North America and Eurasia (88 to 100%). The results suggest a shared ancestry with isolates from other geographical locations, rather than geographical speciation, and presumably separate CTV introductions into Jamaica.

show abstract

“…The genomic structure of CTV populations, and their alterations have been detected by the single strand conformational polymorphism (SSCP) technique (Rubio et al, 2000;D'urso et al, 2003;Davino et al, 2005). SSCP is also used in cross-protection studies to monitor the protective isolate in preimmunized plants (Souza et al, 2000a;Corazza-Nunes et al, 2001;Kim et al, 2006), and for virus identification and characterization (Vives et al, 2005;Iglesias et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Stability of Citrus tristeza virus protective isolates in field conditions

Costa

Nunes

Zanutto

et al. 2010

Pesq. agropec. bras.

View full text Add to dashboard Cite

-The objective of this work was to monitor the maintenance of Citrus tristeza virus (CTV) protective isolates stability in selected clones of 'Pêra' sweet orange (Citrus sinensis), preimmunized or naturally infected by the virus, after successive clonal propagations. The work was carried out in field conditions in the north of Paraná State, Brazil. Coat protein gene (CPG) analysis of 33 isolates collected from 16 clones of 'Pêra' sweet orange was performed using single strand conformational polymorphism (SSCP). Initially, the isolates were characterized by symptoms of stem pitting observed in clones. Then viral genome was extracted and used as template for the amplification of CPG by reverse transcription polimerase chain reaction (RTPCR). RTPCR products electrophoretic profiles were analyzed using the Jaccard coefficient and the UPGMA method. The majority of the clones had weak to moderate stem pitting symptoms and its CTV isolates showed alterations in the SSCP profiles. However, the stability of the protective complex has been maintained, except for isolates from two analised clones. Low genetic variability was observed within the isolates during the studied years.Index terms: Citrus sinensis, cross-protection, preimmunization, single strand conformational polymorphism, stem pitting symptoms. Estabilidade de isolados protetores contra Citrus tristeza virus em condições de campoResumo -O objetivo deste trabalho foi monitorar a manutenção da estabilidade de isolados protetores contra Citrus tristeza virus (CTV) em clones selecionados de laranja 'Pêra' (Citrus sinensis) pré-imunizados ou infectados naturalmente pelo vírus, após sucessivas propagações clonais. O trabalho foi realizado em condições de campo, no norte do Estado do Paraná. A análise do gene da capa protéica (GPC) de 33 isolados, coletados de 16 clones de laranjeira 'Pêra', foi realizada com o uso da técnica polimorfismo conformacional da fita simples (SSCP). Inicialmente, os isolados foram caracterizados por meio de sintomas de caneluras observados nos clones. Em seguida, o genoma viral foi extraído e utilizado como molde para a amplificação do GCP com uso da transcrição reversa da reação em cadeia da polimerase (RTPCR). Os perfis eletroforéticos dos produtos da RTPCR foram analisados com emprego do coeficiente de Jaccard e do método UPGMA. A maioria dos clones apresentou sintomas fracos a moderados de caneluras, bem como alterações nos perfis dos isolados de CTV. Contudo, a estabilidade dos complexos protetores foi mantida, com exceção dos isolados presentes em dois dos clones analisados. Foi observada baixa variabilidade genética nos isolados durante os anos avaliados.Termos para indexação: Citrus sinensis, proteção cruzada, pré-imunização, polimorfismo conformacional da fita simples, sintomas de caneluras.

show abstract

Population structure of Citrus tristeza virus from field Argentinean isolates

Cited by 31 publications

References 39 publications

East Adriatic—a reservoir region of severe Citrus tristeza virus strains

East Adriatic—a reservoir region of severe Citrus tristeza virus strains

Detection and characterization of Citrus tristeza virus stem pitting isolates in Jamaica

Stability of Citrus tristeza virus protective isolates in field conditions

Contact Info

Product

Resources

About