Single and Mixed Infections of Plant RNA and DNA Viruses are Prevalent in Commercial Sweet Potato in Honduras and Guatemala

Persistent Link:
http://hdl.handle.net/10150/578609
Title:
Single and Mixed Infections of Plant RNA and DNA Viruses are Prevalent in Commercial Sweet Potato in Honduras and Guatemala
Author:
Avelar, Ana Sofia
Issue Date:
2015
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Sweet potato is one of the 15 most important food crops worldwide. At least 30 different virus species, belonging to different taxonomic groups affect sweet potato. Little is known about the viruses present in sweet potato crops in Central America, which is the primary origin of sweet potato. The objective of this study was to design and implement primers for use in polymerase chain reaction (PCR) and Reverse transcription-PCR (RT-PCR) to identify and survey the diversity of plant viruses infecting sweet potato in Honduras and Guatemala. Primers were designed and used to amplify, clone, and sequence a taxonomically informative fragment of the coat protein (CP) gene for whitefly-transmitted geminiviruses (herein, sweepoviruses) and potyviruses, and of the heat shock protein 70 (HSP70) for the Crinivirus, Sweet potato chlorotic stunt virus (SPCSV). The partial genome sequences were used for identification based on phylogenetic relationships with reference sequences available in the GenBank database. All three of the plant virus groups identified in this study were found to occur either in single or in multiple infections. Results of the sequence analyses indicated that the genomic regions amplified in this study were capable of discriminating among potyvirus species, and strains of SPCSV. With respect to potyvirus, all isolates were identified as Sweet potato feathery mottle virus (SPFMV) species, except for two, which grouped phylogenetically with Sweet potato virus G (SPVG) and Sweet potato virus C (SPVC). All sweepoviruses detected in sweet potato plants belonged to a single phylogenetically, well-supported group that contains all other previously described geminiviruses (sweepoviruses) associated with sweet potato or closely related host species. These results demonstrate that the primers designed for amplification of plant virus species commonly recognized to infect sweet potato, effectively detected the viruses singly and in mixtures from symptomatic plants, and that the resultant fragment, when subjected to cloning and DNA sequenced, was phylogenetically informative at the species and/or strain levels, depending on the virus group.
Type:
text; Electronic Thesis
Keywords:
heat shock protein; potyvirus; sweepovirus; Sweet potato chlorotic stunt virus; Plant Pathology; coat protein
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Graduate College; Plant Pathology
Degree Grantor:
University of Arizona
Advisor:
Brown, Judith K.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titleSingle and Mixed Infections of Plant RNA and DNA Viruses are Prevalent in Commercial Sweet Potato in Honduras and Guatemalaen_US
dc.creatorAvelar, Ana Sofiaen
dc.contributor.authorAvelar, Ana Sofiaen
dc.date.issued2015en
dc.publisherThe University of Arizona.en
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en
dc.description.abstractSweet potato is one of the 15 most important food crops worldwide. At least 30 different virus species, belonging to different taxonomic groups affect sweet potato. Little is known about the viruses present in sweet potato crops in Central America, which is the primary origin of sweet potato. The objective of this study was to design and implement primers for use in polymerase chain reaction (PCR) and Reverse transcription-PCR (RT-PCR) to identify and survey the diversity of plant viruses infecting sweet potato in Honduras and Guatemala. Primers were designed and used to amplify, clone, and sequence a taxonomically informative fragment of the coat protein (CP) gene for whitefly-transmitted geminiviruses (herein, sweepoviruses) and potyviruses, and of the heat shock protein 70 (HSP70) for the Crinivirus, Sweet potato chlorotic stunt virus (SPCSV). The partial genome sequences were used for identification based on phylogenetic relationships with reference sequences available in the GenBank database. All three of the plant virus groups identified in this study were found to occur either in single or in multiple infections. Results of the sequence analyses indicated that the genomic regions amplified in this study were capable of discriminating among potyvirus species, and strains of SPCSV. With respect to potyvirus, all isolates were identified as Sweet potato feathery mottle virus (SPFMV) species, except for two, which grouped phylogenetically with Sweet potato virus G (SPVG) and Sweet potato virus C (SPVC). All sweepoviruses detected in sweet potato plants belonged to a single phylogenetically, well-supported group that contains all other previously described geminiviruses (sweepoviruses) associated with sweet potato or closely related host species. These results demonstrate that the primers designed for amplification of plant virus species commonly recognized to infect sweet potato, effectively detected the viruses singly and in mixtures from symptomatic plants, and that the resultant fragment, when subjected to cloning and DNA sequenced, was phylogenetically informative at the species and/or strain levels, depending on the virus group.en
dc.typetexten
dc.typeElectronic Thesisen
dc.subjectheat shock proteinen
dc.subjectpotyvirusen
dc.subjectsweepovirusen
dc.subjectSweet potato chlorotic stunt virusen
dc.subjectPlant Pathologyen
dc.subjectcoat proteinen
thesis.degree.nameM.S.en
thesis.degree.levelmastersen
thesis.degree.disciplineGraduate Collegeen
thesis.degree.disciplinePlant Pathologyen
thesis.degree.grantorUniversity of Arizonaen
dc.contributor.advisorBrown, Judith K.en
dc.contributor.committeememberBrown, Judith K.en
dc.contributor.committeememberPryor, Barryen
dc.contributor.committeememberXiong, Zhongguoen
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