Progress 07/01/07 to 06/30/12
Outputs
OUTPUTS: The complete nucleotide sequences of the isolate of apple chlorotic leaf spot virus (ACLSV) and the isolate of Asian prunus virus (APV) infecting the oriental germplasm 'Ta Tao 5' have been determined. There are significant mismatches between the sequence of this isolate of ACLSV and other complete genomic sequences published for ACLSV. The sequence for APV is novel. Together this information has allowed us to explain inconsistencies in our ability to detect this particular isolate of ACLSV by PCR using published primers and has confirmed the presence of APV in Ta Tao 5. This latter finding has allowed us to eliminate APV from involvement in the bloom delay associated with graft-transmissible agents found in Ta Tao 5. The presence of two distinct apscaviroids (Apple fruit crinkle viroid and Citrus viroid VI) in persimmon growing at Musser Fruit Farm, Clemson University has been demonstrated using PCR. Preliminary evidence suggests that the presence of both is associated with the disease of persimmons (blackening of the veins and shoot death) that has been plaguing persimmon plantings in the southeastern US for the past 20 years. However, although additional samples obtained from Kentucky contained the same viroids (Apple fruit crinkle viroid and Citrus viroid VI ), they did not display the typical symptoms. Grafting experiments established in 2009 in an attempt to provide convincing biological evidence that the presence of viroids is associated with this disease have as yet provided inconclusive results. A second series of molecular tests completed on this material in the spring of 2012 also provided inconclusive results. Both series of plants will be retested for the presence of these viroids during the next growing season. Comparative tests to determine whether the presence of one or more viroids in Camellia japonica can be associated with symptoms of camellia yellow mottle disease continue but progress is limited as a reliable procedure for the extraction of viroid nucleic acid from camellias has yet to be achieved despite attempts involving a number of different procedures. Current problems appear to stem from the co-extraction of compounds (polyphenols) that inhibit/interfere with PCR tests delivering inconsistent amplification. A collaboration with USDA, Beltsville has allowed access to a multiple probe capable of detecting six apscaviroids in a single experiment. This has been used to detect the presence of at least one of the following viroids in camellia: Apple fruit crinkle viroid (previously detected and confirmed using PCR and sequencing of amplicons), Apple dimple fruit viroid, Peach latent mosaic viroid, Apple scar skin viroid, Hop stunt viroid and Pear blister canker viroid. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
This is the first complete genomic sequence for an isolate of ACLSV that infects peach. Because of the history of this isolate, and the mode of transmission of this virus, this may be the first complete sequence for an isolate of ACLSV from China. This is the first complete genomic sequence for an isolate of APV. The identification of Apple fruit crinkle viroid and Citrus Viroid VI provided the opportunity to confirm and prove their association with sudden death syndrome (SDS) of persimmon as it occurs at other locations. Identification of commercially significant cultivars of oriental persimmon (Diospyros kaki) in which viroids are not detected would allow comparisons between diseased and non-diseased trees that might provide information to growers on the effect of viroids on yield and growth of trees. Understanding and confirmation of the possible role of viroids in yellow mottle disease of camellia will allow steps to be taken to manage the disease. Detection of the presence of one or more viroids in camellia cultivars might explain the wide diversity of symptoms associated with camellia yellow mottle disease both in terms of leaf symptoms and variegation of blooms. Manipulation of the viroid content may also offer breeders even more means of altering flower breaking and variegation of foliage. The sequence data that we have obtained for some viroids in Camellia suggest that they are distantly related to other apscaviroids and may indeed be previously unreported viroids. Knowledge that these viroids are present in the US in symptomless or previously unrecognized hosts may require changes in quarantine regulations and management practices.. For example: Apple fruit crinkle viroid was not recognized as being present in North America in RSPM No. 35 Guidelines for the Movement of Stone and Pome Fruit Trees and Grapevines into a NAPPO Member Country (2009).
Publications
- Scott, S.W., Zimmerman, M.T. 2008. Partial nucleotide sequences of the RNA 1 and RNA 2 of lilac ring mottle confirm that this virus should be considered a member of subgroup 2 of the genus Ilarvirus. Archives of Virology 153: 2169-2172.
- Marini,D.B., Gibson,P.G. and Scott,S.W. 2008 The complete nucleotide sequence of an isolate of apple chlorotic leaf spot virus from peach (Prunus persica (L.) Batch). Archives of Virology 153: 1003-1005.
- Scott, S.W., Zimmerman, M.T. 2008. The complete sequence of ligustrum necrotic ringspot virus, a novel carlavirus. Archives of Virology 153: 393-396.
- Marini,D.B., Gibson,P.G. and Scott,S.W. 2009 The complete nucleotide sequence of an isolate of Asian prunus virus 1 from peach [Prunus persica (L) Batch]. Archives of Virology 154:1375-1377.
- Scott, S.W., Zimmerman, M.T. 2009. The nucleotide sequences of the RNA 1 and RNA 2 of asparagus virus 2 show a close relationship to citrus variegation virus. Archives of Virology 154:719-722.
- Tzanetakis I, Martin RR, Scott, SW (2010)Genomic sequences of blackberry chlorotic ringspot virus and strawberry necrotic shock virus and the phylogenyof viruses in subgroup 1 of the genus Ilarvirus. Archives of Virology 155:557-561
- Kim BT, Gibson PG, Scott SW (2010)Expression of the coat protein genes of PNRSV and PDV in the synergistic disease peach stunt. Julius-Kuhn-Archiv 427:114-117.
- Gibson PG, Reighard G, Marini D, Scott, SW (2010)Effects associated with graft-transmissible agents found in the peach variety 'Ta Tao 5'.Julius-Kuhn-Archiv 427:284-288.
- Kirkpatrick, B.C., Pasquini, G., Scott, S., and Foissac, X. (2011) Economic Impact of Pome and Stone Fruit Phytoplasmas. In 'Virus and Virus-like Diseases of Pome and Stone Fruits' Eds Ahmed Hadidi, Marina Barba, Thierry Candresse, and Wilhelm Jelkmann. APS Press
- Howell, W.E., Thompson, D., and Scott, S. (2011) Virus-like Disorders of Fruit Trees with Undetermined Etiology. In 'Virus and Virus-like Diseases of Pome and Stone Fruits' Eds Ahmed Hadidi, Marina Barba, Thierry Candresse, and Wilhelm Jelkmann. APS Press
|
Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: The association between the presence of two distinct apscaviroids (Apple fruit crinkle viroid and Citrus viroid VI) in persimmon, and the disease of persimmons (blackening of the veins and shoot death- sudden death syndrome) that has been plaguing persimmon plantings in the southeastern US for the past 20 years continues to be investigated. Grafting experiments, established in fall 2009 to provide convincing biological evidence that the presence of these viroids is associated with this disease, have been allowed to grow and were analyzed using PCR but provided inconclusive results. A second series of molecular tests will be completed on this material in the spring of 2012. Seedlings of oriental persimmon from 5 cultivars have been produced to allow a repeat/and expansion of the grafting experiments established in 2009. Research attempting to associate the symptoms of camellia yellow mottle disease with the presence of viroids continues. Collaborations continue with the America Camellia Society Gardens, Marshallville, GA, and Cam-too Nursery, Greensboro, NC. The contributions of the late Hulyn Smith, Valdosta, GA have been replaced by those of a colleague, Mark Crawford, Valdosta. All three collaborators willingly supply material and information to help with the research. Reliable, reproducible PCR tests that identify the viroids unambiguously are the goal of the project. Current problems appear to stem from the co-extraction of compounds (polyphenols) that inhibit/interfere with PCR test delivering inconsistent amplification. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Understanding and confirmation of the possible role of viroids in both sudden death syndrome of persimmon and yellow mottle disease of camellia will allow steps to be taken to manage both diseases. Knowledge that these viroids are present in the US in symptomless or previously unrecognized hosts may require changes in quarantine regulations and management practices. The sequence data that we have obtained for some viroids in Camellia suggest that they are distantly related to other apscaviroids but may indeed be previously unreported viroid species.
Publications
- No publications reported this period
|
Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: The association between the presence of two distinct apscaviroids (Apple fruit crinkle viroid and Citrus viroid VI)in persimmon growing at Musser Fruit Farm, Clemson University and the disease of persimmons (blackening of the veins and shoot death - sudden death syndrome) that has been plaguing persimmon plantings in the southeastern US for the past 20 years continues to be investigated. Grafting experiments established in fall 2009 to provide convincing biological evidence that the presence of viroids is associated with this disease have been allowed to grow and will be analyzed in 2011. Comparative tests to determine whether the presence of one or more viroids in Camellia japonica can be associated with symptoms of camellia yellow mottle disease are underway. Collaborations have been established with the America Camellia Society Gardens, Marshallville, GA, Cam-too Nursery, Greensboro, NC and Mr Hulyn Smith, Valdosta, GA to supply material for testing. A collaboration with USDA, Beltsville has allowed access to a multiple probe capable of detecting six apscaviroids in a single experiment. This has been used to detect the presence of at least one of the following viroids, Apple fruit crinkle viroid (previously detected and confirmed using PCR and sequencing of amplicons), Apple dimple fruit viroid, Peach latent mosaic viroid, Apple scar skin viroid, Hop stunt viroid and Pear blister canker viroid. PARTICIPANTS: Collaborations have been established with the America Camellia Society Gardens, Marshallville, GA. Cam-too Nursery, Greensboro, NC.and Mr Hulyn Smith, Valdosta, GA. USDA,Beltsville, MD. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Understanding and confirmation of the possible role of viroids in both sudden death syndrome of persimmon and yellow mottle disease of camellia will allow steps to be taken to manage both diseases. Knowledge that these viroids are present in the US may lead to revision of quarantine regulations. For example: Apple fruit crinkle viroid was not recognized as being present in North America in RSPM No. 35 Guidelines for the Movement of Stone and Pome Fruit Trees and Grapevines into a NAPPO Member Country (2009). That the viroid is present in symptomless or previously unrecognized hosts may require changes in regulations and management practices.
Publications
- Tzanetakis I, Martin RR, Scott, SW (2010)Genomic sequences of blackberry chlorotic ringspot virus and strawberry necrotic shock virus and the phylogenyof viruses in subgroup 1 of the genus Ilarvirus. Archives of Virology 155:557-561
- Kim BT, Gibson PG, Scott SW (2010)Expression of the coat protein genes of PNRSV and PDV in the synergistic disease peach stunt. Julius-Kuhn-Archiv 427:114-117.
- Gibson PG, Reighard G, Marini D, Scott, SW (2010)Effects associated with graft-transmissible agents found in the peach variety 'Ta Tao 5'.Julius-Kuhn-Archiv 427:284-288.
|
Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: The association between the presence of two distinct apscaviroids in persimmon growing at Musser Fruit Farm, Clemson University and the disease of persimmons (blackening of the veins and shoot death - sudden death syndrome) that has been plaguing persimmon plantings in the south eastern US for the past 20 years continues to be investigated. Additional samples obtained from Kentucky contained the same viroids but did not display the typical symptoms. Grafting experiments have been established in an attempt to provide convincing biological evidence that the presence of viroids is associated with this disease. Other work has detected the presence of several apscaviroids in Camellia japonica. Comparative tests to determine whether the presence of one or more of these viroids can be associated with symptoms of camellia yellow mottle disease are under way. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: This information will be of value to people who propagate persimmon and who develop new cultivars of camellia PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Understanding and confirmation of the possible role of viroids in both sudden death syndrome of persimmon and yellow mottle disease of camellia will allow steps to be taken to manage both diseases. For example identification of commercially significant cultivars of oriental persimmon (Diospyros kaki)in which viroids are not detected would allow comparisons between diseased and non-diseased trees that would provide information to growers on the effect of viroids on yield and growth of trees. Detecting the presence of one or more viroids in camellia cultivars might explain the wide diversity of symptoms associated with camellia yellow mottle disease both in terms of leaf symptoms and variegation of blooms.
Publications
- Marini,D.B., Gibson,P.G. and Scott,S.W. 2009 The complete nucleotide sequence of an isolate of Asian prunus virus 1 from peach [Prunus persica (L) Batch]. Archives of Virology 154:1375-1377.
- Scott, S.W., Zimmerman, M.T. 2009. The nucleotide sequences of the RNA 1 and RNA 2 of asparagus virus 2 show a close relationship to citrus variegation virus. Archives of Virology 154:719-722.
|
Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: The complete nucleotide sequence of the isolate of Asian prunus virus (APV) infecting the oriental germplasm 'Ta Tao 5' has been determined. This information confirms the presence of APV and has allowed us to eliminate this virus from involvement in the bloom delay associated with graft-transmissible agents found in Ta Tao 5. The presence of two distinct apscaviroids in persimmon growing at Musser Fruit Farm, Clemson University has been demonstrated. Preliminary evidence suggest that the presence of both is associated with the disease of persimmons (blackening of the veins and shoot death) that has been plaguing persimmon plantings in the south eastern US for the past 20 years. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This is the first complete genomic sequence for an isolate of APV. The identification of these 2 apscaviroids provides the opportunity to confirm and prove their association with this disease as it occurs at other locations. Knowledge of the graft-transmissible agents now associated with this disease provides the opportunity either to select germplasm sources in which the viroids are not detectable or to use therapy to eliminate them and thus provide pathogen-tested stock for propagation.
Publications
- Scott, S.W., Zimmerman, M.T. 2008. Partial nucleotide sequences of the RNA 1 and RNA 2 of lilac ring mottle confirm that this virus should be considered a member of subgroup 2 of the genus Ilarvirus. Archives of Virology 153: 2169-2172.
- Marini,D.B., Gibson,P.G. and Scott,S.W. 2008 The complete nucleotide sequence of an isolate of apple chlorotic leaf spot virus from peach (Prunus persica (L.) Batch). Archives of Virology 153: 1003-1005.
- Scott, S.W., Zimmerman, M.T. 2008. The complete sequence of ligustrum necrotic ringspot virus, a novel carlavirus. Archives of Virology 153: 393-396.
|
Progress 01/01/07 to 12/31/07
Outputs
The complete nucleotide sequence of the isolate of ACLSV infecting the oriental germplasm 'Ta Tao 5' has been determined. This information has allowed us to explain inconsistencies in our ability to detect this particular isolate of ACLSV by PCR using published primers. There are significant mismatches between the sequence of this isolate of the virus and other complete genomic sequences published for ACLSV.
Impacts
This is the first complete genomic sequence for an isolate of ACLSV that infects peach. Because of the history of this isolate, and the mode of transmission of this virus, this may be the first complete sequence for and isolate of ACLSv from China.
Publications
- No publications reported this period
|
|