scholarly journals Construction and application of infectious citrus viroids for biological indexing

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
C Steyn ◽  
G Cook ◽  
J T Burger ◽  
H J Maree
Keyword(s):  
Biological Indexing ◽  
Citrus Viroids

scholarly journals Molecular Detection and Prevalence of Citrus Viroids in Texas

HortScience ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 600-604 ◽  
Author(s):  
Madhurababu Kunta ◽  
J.V. da Graça ◽  
Mani Skaria
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Rt Pcr ◽  
Lower Rio Grande Valley ◽  
Biological Indexing ◽  
Hop Stunt Viroid ◽  
Viroid Infection ◽  
Citrus Viroids ◽  
Commercially Important ◽  
Polymerase Chain ◽  
Alternative Detection

Viroids are graft- or mechanically transmissible agents, disseminated through budding. Biological indexing of commercially important citrus cultivars grown in the Lower Rio Grande Valley of Texas showed that many are infected with citrus viroids. Most of these trees carried more than one viroid. In most cases, the infected trees are asymptomatic carriers because sour orange, the predominant rootstock used in Texas, does not show symptoms of viroid infection. Detection of viroids through biological indexing on sensitive indicator plants followed by sequential polyacrylamide gel electrophoresis (sPAGE) is the gold standard but is time-consuming and requires plants to be kept at optimum conditions. A conditional use of reverse transcriptase–polymerase chain reaction (RT-PCR) provides an efficient and alternative detection of viroids for use in the Texas virus-free citrus budwood certification program. RT-PCR could be useful in Texas to help expedite the evaluation for the presence of viroids before conducting the final biologic indexing. Using RT-PCR, we could detect, clone, and sequence full-length viroids of Citrus exocortis viroid (CEVd), Hop stunt viroid (HSVd) (both cachexia and noncachexia variants), Citrus viroid-III (Citrus dwarfing viroid), and Citrus viroid-IV (Citrus bark cracking viroid) from a collection of viroid-inoculated grapefruit plants. The source plants were previously shown to be viroid-infected by biological indexing on Etrog citron plants. Based on our results, RT-PCR can be a conditional substitute for biological indexing of mother trees in foundation blocks and shoot tip-grafted trees in the virus-free budwood program. A positive RT-PCR result has a serendipitous value because those trees can be discarded from the pool before expensive biological indexing.

scholarly journals Interactions Between Citrus Viroids Affect Symptom Expression and Field Performance of Clementine Trees Grafted on Trifoliate Orange

2006 ◽  
Vol 96 (4) ◽  
pp. 356-368 ◽  
Author(s):  
C. Vernière ◽  
X. Perrier ◽  
C. Dubois ◽  
A. Dubois ◽  
L. Botella ◽  
...  
Keyword(s):  
Field Performance ◽  
Fruit Yield ◽  
Symptom Expression ◽  
Trifoliate Orange ◽  
Synergistic Interactions ◽  
Expression Tree ◽  
Mean Estimation ◽  
Hop Stunt Viroid ◽  
Citrus Viroids ◽  
Synergistic Relationships

Citrus exocortis viroid (CEVd), Citrus bent leaf viroid (CBLVd), a noncachexia variant of Hop stunt viroid (HSVd), Citrus viroid III (CVd-III), and Citrus viroid IV (CVd-IV) were co-inoculated as two-, three-, four-, and five-viroid mixtures to Clementine trees grafted on trifoliate orange to evaluate their effect on symptom expression, tree growth, and fruit yield. Most trees infected with CEVd-containing viroid mixtures developed exocortis scaling symptoms, as did CEVd alone, whereas most trees infected with HSVd- or CVd-IV-containing mixtures developed bark-cracking symptoms. Trees infected with mixtures containing both CEVd and CVd-IV revealed the existence of antagonism between these two viroids in terms of the expected bark-scaling and cracking symptoms. Synergistic interactions also were identified in trees infected with certain viroid combinations that, in spite of lacking CEVd, expressed exocortis-like scaling symptoms. Viroid interactions also affected the expected response of trees in terms of vegetative growth and fruit yield. Trees infected with viroid combinations containing CEVd or CVd-III were smaller and produced less fruit than trees infected with mixtures not containing these viroids. Viroid interactions on scion circumference and cumulative fruit yield, in terms of additivity of their effects, were statistically confirmed using a factorial analysis of variance model with two mean estimation approaches. In single-viroid infections, CEVd, CVd-III, and, to a lesser extent, CBLVd consistently and significantly reduced tree size and fruit yield. Conversely, HSVd and CVd-IV slightly increased fruit yield and reduced scion circumference. Rare and not consistent significant interactions were detected with the five-, four-, and three-viroid combinations. Antagonistic interactions between CEVd and CVd-III or CBLVd and CVd-III were revealed over the years with consistent significance. The antagonistic interaction between CEVd and CVd-IV was highly significant over the years when additional viroids were present; however, this antagonism appeared much later in the case of an exclusive interaction. HSVd and CVd-IV showed a consistent and significant synergistic interaction on yield only when both viroids were exclusively present. These results demonstrate antagonistic or synergistic relationships between citrus viroids depending on the viroid mixtures present in the host.

scholarly journals PCR Diagnosis of Some Citrus Viroids in Field Samples

1996 ◽  
Vol 13 (13) ◽  
Author(s):  
M. Tessitori ◽  
R. La Rosa ◽  
G. Albanese ◽  
A. Catara
Keyword(s):  
Pcr Diagnosis ◽  
Field Samples ◽  
Citrus Viroids

scholarly journals Sequence analysis of three citrus viroids infecting a single Tunisian citrus tree (Citrus, reticulata, Clementine)

2006 ◽  
Vol 29 (4) ◽  
pp. 705-710 ◽  
Author(s):  
Amine Elleuch ◽  
Fattouma Djilani Khouaja ◽  
Imen Hamdi ◽  
Nabiha Bsais ◽  
Jean-Pierre Perreault ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Citrus Reticulata ◽  
Citrus Tree ◽  
Citrus Viroids

scholarly journals IImproved Indexing of Citrus Viroids

1993 ◽  
Vol 12 (12) ◽  
Author(s):  
N. Duran-Vila ◽  
J. A. Pina ◽  
L. Navarro
Keyword(s):  
Citrus Viroids

scholarly journals Practical Field Detection of Citrus Viroids in Florida by RT-PCR

2002 ◽  
Vol 15 (15) ◽  
Author(s):  
S. M. Garnsey ◽  
D. L. Zies ◽  
M. Irey ◽  
P. J. Sieburth ◽  
JS S. Semancik ◽  
...  
Keyword(s):  
Rt Pcr ◽  
Field Detection ◽  
Citrus Viroids ◽  
Practical Field

scholarly journals Performance of Navelina Sweet Orange on Five Rootstocks Inoculated with Citrus Viroids

2005 ◽  
Vol 16 (16) ◽  
Author(s):  
Salvatore Davino ◽  
M. Davino ◽  
A. Caruso ◽  
G. Sorrentino ◽  
M. Guardo ◽  
...  
Keyword(s):  
Sweet Orange ◽  
Citrus Viroids
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