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dc.rights.licenseAtribución-NoComercial 4.0 Internacional
dc.contributor.advisorMarón Montoya, Mauricio (Thesis advisor)
dc.contributor.authorOsorio Giraldo, Inés Elvira
dc.date.accessioned2019-06-24T21:10:59Z
dc.date.available2019-06-24T21:10:59Z
dc.date.issued2012
dc.identifier.urihttps://repositorio.unal.edu.co/handle/unal/9820
dc.description.abstractEl cultivo de papa es uno de los renglones agrícolas de mayor importancia en Colombia; se extiende a 128.701 ha y genera una producción anual de 2.3 millones de ton año-1. Desde el punto vista fitosanitario, la papa se ve afectada por diversos problemas, destacándose en los últimos años la reemergencia de la Sarna polvosa causada por el protozoario del suelo Spongospora subterranea f.sp. subterranea (Sss). El efecto de esta enfermedad se refleja en el deterioro de la calidad del tubérculo y en la reducción de la producción, al afectar el sistema radicular de las plantas. Además, Sss es el vector natural del Potato mop-top virus (PMTV), uno de los virus prevalentes en la región Andina y que presenta carácter cuarenteneario en diferentes países del mundo. En este trabajo se evaluaron los niveles de variabilidad genética de aislamientos Sss y PMTV obtenidos en cultivos de papa de los departamentos de Antioquia, Boyacá, Cundinamarca y Nariño. En el caso de Sss se estudiaron los niveles de variación de 127 aislamientos, a partir de la secuenciaciación de las regiones ITS del ADN ribosomal (ADNr), encontrándose la presencia de tres variantes principales, dos de las cuales (Tipos I y II) han sido reportadas en otros países del mundo, mientras que el Tipo III hasta ahora solo se ha encontrado en Colombia. Con base en esta información se diseñó una prueba de PCR-RFLPs que permite identificar los ribotipos del patógeno responsables de la Sarna polvosa en una región determinada. Para PMTV se evaluaron los niveles de identidad de 38 aislamientos de los cuatro departamentos bajo estudio, a partir de la secuenciación de los genes de la cápside viral (CP) y del segundo gen del triple bloque de genes (TGB2), encontrándose la presencia de dos variantes del virus, una que representa el genotipo mundialmente reportado para este virus y la otra, que hasta ahora sólo se ha encontrado en Colombia y que dado el bajo nivel de identidad (76%) con respecto al primer grupo, posiblemente representa una nueva especie de pomovirus. Finalmente, dos de las cepas de PMTV de Antioquia y Boyacá fueron secuenciadas para sus ARN 2 y 3, lográndose un 83% del segmento genómico de ARN 2 y 87% para el ARN 3 y encontrándose que comparten niveles de identidad superiores al 97% con respecto a otros aislamientos previamente caracterizados en el Norte de Europa. Se espera que los resultados de esta investigación sean utilizados para el diseño de herramientas ddiagnóstico que apoyen los esquemas de certificación de tubérculo semilla y los programas de mejoramiento genético de papa que se adelantan en Colombia./Abstract. Powdery scab (Spongospora subterranea f.sp. subterranea – Sss) is one of the most important re-emerging diseases of potato crops in Colombia. Sss can cause severe root damage and compromise the quality of tubers. Moreover, Sss zoospores can also serve as vector of Potato mop-top virus (PMTV, Pomovirus). Sss can survive in the soil for decades due to the formation of resistance structures or cystosori. For this reason, the disease can only be efficiently controlled by using resistant potato varieties and certified seed tubers. In this work, the level of variation of 127 Sss isolates from the Colombian provinces of Antioquia, Boyacá, Cundinamarca and Nariño was evaluated. This information is of great value for genetic improvement programs of potato and can also be used in the design of asymptomatic detection tests. Phylogenetic analysis of ITS rDNA sequences revealed the existence of three Sss variants. Types I and II have been reported in other countries while type III has only been found in Colombia. This information was used to design a PCR-RLFP test to discriminate different powdery scab ribotypes. The other hand, Sss is a vector for Potato mop-top virus (PMTV), a prevalent virus in the Andean region and quarentenary in several countries. However little is known about its biology, pathogenicity and diversity. In order to fill these gaps in knowledge, genes encoding for the viral coat protein (CP) and the triple gene block (TGB2) were sequenced from PMTV isolates obtained in the top four potato-producing provinces in Colombia. Additionaly, RNA2 and RNA3 from two isolates were almost sequenced to completion (83%). Phylogenetic analysis based on the CP sequence revealed the presences of two clades. The first clade included reference strains from all over the world and 19 Colombian PMTV isolates. The second clade shared less than 76% identity with clade 1, suggesting a new pomovirus species. Complete genome sequencing is required to confirm this hypothesis. Phylogenetic analysis using the TGB2 gene grouped all sequences in a single clade. Sequence analysis of segments 2 and 3 of the viral genomes revealed 94% sequence identity with PMTV isolates from Czech Republic and Sweden. These findings will be helpful in the development of diagnostic tools for PMTV in the Andes and will support tuber-seed certification and genetic improvement programs.
dc.description.abstractAbstract: Powdery scab (Spongospora subterranea f.sp. subterranea – Sss) is one of the most important re-emerging diseases of potato crops in Colombia. Sss can cause severe root damage and compromise the quality of tubers. Moreover, Sss zoospores can also serve as vector of Potato mop-top virus (PMTV, Pomovirus). Sss can survive in the soil for decades due to the formation of resistance structures or cystosori. For this reason, the disease can only be efficiently controlled by using resistant potato varieties and certified seed tubers. In this work, the level of variation of 127 Sss isolates from the Colombian provinces of Antioquia, Boyacá, Cundinamarca and Nariño was evaluated. This information is of great value for genetic improvement programs of potato and can also be used in the design of asymptomatic detection tests. Phylogenetic analysis of ITS rDNA sequences revealed the existence of three Sss variants. Types I and II have been reported in other countries while type III has only been found in Colombia. This information was used to design a PCRRLFP test to discriminate different powdery scab ribotypes. The other hand, Sss is a vector for Potato mop-top virus (PMTV), a prevalent virus in the Andean region and quarentenary in several countries. However little is known about its biology, pathogenicity and diversity. In order to fill these gaps in knowledge, genes xiii encoding for the viral coat protein (CP) and the triple gene block (TGB2) were sequenced from PMTV isolates obtained in the top four potato-producing provinces in Colombia. Additionaly, RNA2 and RNA3 from two isolates were almost sequenced to completion (83%). Phylogenetic analysis based on the CP sequence revealed the presences of two clades. The first clade included reference strains from all over the world and 19 Colombian PMTV isolates. The second clade shared less than 76% identity with clade 1, suggesting a new pomovirus species. Complete genome sequencing is required to confirm this hypothesis. Phylogenetic analysis using the TGB2 gene grouped all sequences in a single clade. Sequence analysis of segments 2 and 3 of the viral genomes revealed 94% sequence identity with PMTV isolates from Czech Republic and Sweden. These findings will be helpful in the development of diagnostic tools for PMTV in the Andes and will support tuber-seed certification and genetic improvement programs.
dc.format.mimetypeapplication/pdf
dc.language.isospa
dc.relation.ispartofUniversidad Nacional de Colombia Sede Medellín Facultad de Ciencias Escuela de Geociencias
dc.relation.ispartofEscuela de Geociencias
dc.rightsDerechos reservados - Universidad Nacional de Colombia
dc.rights.urihttp://creativecommons.org/licenses/by-nc/4.0/
dc.subject.ddc55 Ciencias de la tierra / Earth sciences and geology
dc.titleVariabilidad genética de spongospora subterranea y su virus asociado pmtv en Colombia
dc.typeTrabajo de grado - Maestría
dc.type.driverinfo:eu-repo/semantics/masterThesis
dc.type.versioninfo:eu-repo/semantics/acceptedVersion
dc.identifier.eprintshttp://bdigital.unal.edu.co/6845/
dc.description.degreelevelMaestría
dc.relation.referencesOsorio Giraldo, Inés Elvira (2012) Variabilidad genética de spongospora subterranea y su virus asociado pmtv en Colombia. Maestría thesis, Universidad Nacional de Colombia, Sede Medellín.
dc.rights.accessrightsinfo:eu-repo/semantics/openAccess
dc.subject.proposalSarna polvosa
dc.subject.proposalSolanum tuberosum
dc.subject.proposalPotato mop-top virus
dc.subject.proposalPowdery scab
dc.subject.proposalSolanum tuberosum
dc.subject.proposalPotato mop-top virus
dc.type.coarhttp://purl.org/coar/resource_type/c_bdcc
dc.type.coarversionhttp://purl.org/coar/version/c_ab4af688f83e57aa
dc.type.contentText
dc.type.redcolhttp://purl.org/redcol/resource_type/TM
oaire.accessrightshttp://purl.org/coar/access_right/c_abf2


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Atribución-NoComercial 4.0 InternacionalThis work is licensed under a Creative Commons Reconocimiento-NoComercial 4.0.This document has been deposited by the author (s) under the following certificate of deposit