Indigenous and introduced species of the Bemisia tabaci complex in sweet potato crops from Argentina

La batata (Ipomoea batatas (L.) Lam) es uno de los cultivos más importantes en el mundo. Recientemente se observó una severa sintomatología viral en cultivos de la región pampeana argentina, en la que están identificados begomovirus y crinivirus, ambos transmitidos exclusivamente por mosca blanca. El objetivo de este estudio fue identificar las especies de B. tabaci en cultivos de batata en Colonia Caroya, mediante el análisis de secuencias mitocondriales de la citocromo oxidasa subunidad I (mtCOI). Se identificaron dos haplotipos (especies crípticas) ya descriptos en el mundo: New World2 (especie nativa) y MEAM1 (especie introducida). Los resultados indican la presencia de ambas especies, las cuales son potenciales vectores de begomovirus y crinivirus en batata en Argentina.Sweet potato (Ipomoea batatas (L.) Lam) is one of the most important crops worldwide. Recently, the appearance of severe viral symptoms has been observed in sweet potato crops in the pampas region of Argentina and both begomovirus and crinivirus, exclusively transmitted by whiteflies, have been identified. The aim of this study was to identify B. tabaci species from sweet potato crops in Colonia Caroya by analysing mitochondrial cytochrome c oxidase subunit I (mtCOI) sequences. Two previously described haplotypes were identified: New World2 (indigenous species) and MEAM1 (introduced species). The results indicate the presence of both species, which are potential vectors of begomovirus and crinivirus in Argentina.Fil: Alemandri, V.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Martino, Julia Andrea. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Feo, Liliana del Valle. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Truol, G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentin

Temporal and spatial study of the Bemisia tabaci- geminivirus complex using a Geographical Information System (GIS)

Abstracts del XXIV Annual Scientific Meeting, celebrado del 8-10 de noviembre 2007, en Tafí del Valle, Tucumán, Argentina.Currently, GIS are being used in different research fields such as plant pathology as key tools for the study of diseases. The purpose of this study was the temporal and spatial analysis of the Bemisia tabaci -geminivirus complex, using a geographical information system. Data were used on 54 location points where B. tabaci and/ or geminivirus were found in soybean and bean in 2007. The data were incorporated into the GIS Floramap 1.02. A map with the probability surface was thus obtained of the potential locations where B. tabaci-geminivirus might be found, bearing in mind climate features, and using 2007 data. This layer of information was superposed on the probability surface obtained from the data of the previous 2004-2006 period, showing an increase of potential locations, mainly in the provinces of Córdoba, Santa Fe, Entre Ríos, San Luis and Buenos Aires. It may be concluded that the implementation of technology such as GIS in spatial and temporal studies of plant diseases produced by vector-transported viruses is highly useful.Peer reviewe

Species within the Bemisia tabaci (Hemiptera: Aleyrodidae) Complex in Soybean and Bean Crops in Argentina

The White fly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex that contains some of the most damaging pests in tropical and subtropical regions. Recent studies suggested that this complex is composed of at least 24 distinct species. We use the approach from these studies to consider the identity of B. tabaci in Argentina. Previous studies have suggested the presence of a B. tabaci presumably indigenous to the Americas and referred to as the BR biotype in Argentina. We placed the entity referred to as the BR biotype within the B. tabaci cryptic species complex using whiteflies collected in soybean and bean crops in northern and central Argentina. The whiteflies were assigned using the mitochondrial cytochrome oxidase (mtCOI) gene. Four unknown haplotypes plus two Argentina sequences from GenBank formed a cluster that was basal to the rest of theNewWorld sequences. These sequences diverged from the consensus sequence across the range of 3.6 to 4.3%. Applying the species assignment rules of recent studies suggests that the individuals from Argentina form a separate species. A unknown haplotype fell within the New World putative species and formed a distinct cluster with haplotypes from Panama. These results suggest that Argentina has two indigenous species belonging to the B. tabaci cryptic species complex. Rather tan using mtCOI sequencing for all B. tabaci collected, a simple random amplifed polymorphic DNApolymerase chain reaction diagnostic was used and tested along with previously published primers designed to work specially with the BR biotype from Brazil. These primers were either unable to distinguish between the two indigenous members of the complex in Argentina or indicated a difference when none was evident on the basis of mtCOI sequence comparison.Fil: Alemandri, V.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; ArgentinaFil: De Barro, P.. No especifíca;Fil: Bejerman, N.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; ArgentinaFil: Argüello Caro, Evangelina Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Dumón, A. D.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; ArgentinaFil: Mattio, Maria Fernanda. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Rodríguez, S. M.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; ArgentinaFil: Truol G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; Argentin

Identification and biological characterization of Barley yellow striate mosaic virus (BYSMV): a new wheat disease in Argentina

Wheat (Triticum aestivum L.) is the most important winter grain in Argentina. Its production is limited by several factors, including viral diseases. The aim of this study was to identify and characterize a recently detected disease of wheat crops in Argentina. Symptomatic plants were collected from different locations from the wheat production area, Miramar and Balcarce (Buenos Aires), Río Cuarto, Rosales and Marcos Juarez (Córdoba), Paraná (Entre Ríos) and General Pico (La Pampa). Samples were characterized by: electron microscopy (leaf-dip and ultrathin sections), serological tests (with antiserum reacting against different wheat viruses by DAS-ELISA and indirect ELISA), mechanical, seed and vector transmission assays, differential host range, and susceptibility of different wheat cultivars in natural infections. The results showed that this new disease is caused by Barley yellow striate mosaic virus (BYSMV) (Rhabdoviridae-Cytorhabdovirus), a widely distributed virus that can be transmitted to other crops such as barley, oat and triticale. This work representsthe first report of BYSMV in Argentina.El cultivo de trigo (Triticum aestivum L.), es el cereal de invierno de mayor importancia económica en Argentina. Su producción se halla limitada por diversos factores, entre ellos las enfermedades virales. El objetivo del presente trabajo fue identificar y caracterizar biológicamente una enfermedad viral detectada recientemente en el cultivo de trigo en Argentina, que ha presentado elevada incidencia en los últimos años. Para ello, se recolectaron plantas con síntomas en localidades de: Miramar y Balcarce (Buenos Aires), Río Cuarto, Rosales y Marcos Juárez (Córdoba), Paraná (Entre Ríos) y General Pico (La Pampa) de la región triguera Argentina. Las muestras fueron caracterizadas a través de: microscopia electrónica ("leaf-dip" y cortes ultrafinos), serología (con antisueros para diferentes virosis del trigo por DAS-ELISA y ELISA indirecto), transmisión mecánica, por semilla y por vectores (delfácidos), rango de hospedantes diferenciales y susceptibilidad diferencial de diferentes cultivares de trigo en infecciones naturales. Los resultados obtenidos evidenciaron que esta nueva enfermedad es causada por el Barley yellow striate mosaic virus (BYSMV) (Rhabdoviridae-Cytorhabdovirus), un virus ampliamente distribuido a nivel mundial y que representa un riesgo potencial para otros cultivos como cebada, avena y triticale. Este trabajo representa el primer reporte del BYSMV en Argentina.Fil: Dumón, Analía Delina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: Argüello Caro, Evangelina Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Alemandri, María V.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Bainotti, Carlos Tomas. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Mattio, María F.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Rodríguez, Sandra M.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: del Vas, Mariana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Truol, Graciela Ana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentin

African ancestry of New World, Bemisia tabaci-whitefly species

Bemisia tabaci whitefly species are some of the world’s most devastating agricultural pests and plant-virus disease vectors. Elucidation of the phylogenetic relationships in the group is the basis for understanding their evolution, biogeography, gene-functions and development of novel control technologies. We report here the discovery of five new Sub-Saharan Africa (SSA) B. tabaci putative species, using the partial mitochondrial cytochrome oxidase 1 gene: SSA9, SSA10, SSA11, SSA12 and SSA13. Two of them, SSA10 and SSA11 clustered with the New World species and shared 84.8‒86.5% sequence identities. SSA10 and SSA11 provide new evidence for a close evolutionary link between the Old and New World species. Re-analysis of the evolutionary history of B. tabaci species group indicates that the new African species (SSA10 and SSA11) diverged from the New World clade c. 25 million years ago. The new putative species enable us to: (i) re-evaluate current models of B. tabaci evolution, (ii) recognise increased diversity within this cryptic species group and (iii) re-estimate divergence dates in evolutionary time

An integrative approach to discovering cryptic species within the Bemisia tabaci whitefly species complex

Bemisia tabaci is a cryptic whitefly-species complex that includes some of the most damaging pests and plant-virus vectors of a diverse range of food and fibre crops worldwide. We combine experimental evidence of: (i) differences in reproductive compatibility, (ii) hybrid verification using a specific nuclear DNA marker and hybrid fertility confirmation and (iii) high-throughput sequencing-derived mitogenomes, to show that the “Mediterranean” (MED) B. tabaci comprises at least two distinct biological species; the globally invasive MED from the Mediterranean Basin and the “African silver-leafing” (ASL) from sub-Saharan Africa, which has no associated invasion records. We demonstrate that, contrary to its common name, the “ASL” does not induce squash silver-leafing symptoms and show that species delimitation based on the widely applied 3.5% partial mtCOI gene sequence divergence threshold produces discordant results, depending on the mtCOI region selected. Of the 292 published mtCOI sequences from MED/ASL groups, 158 (54%) are low quality and/or potential pseudogenes. We demonstrate fundamental deficiencies in delimiting cryptic B. tabaci species, based solely on partial sequences of a mitochondrial barcoding gene. We advocate an integrative approach to reveal the true species richness within cryptic species complexes, which is integral to the deployment of effective pest and disease management strategies

Climatic characterization of the wheat streak mosaic virus (WSMV) pathology system and its vector Aceria tosichella Keifer using a Geographical Information System (GIS)

Abstracts del XXIV ANNUAL SCIENTIFIC MEETING, celebrado del 8-10 de noviembre 2007, en Tafí del Valle, Tucumán, Argentina.In Argentina, the Wheat streak mosaic virus (WSMV) disease has been present since 2003, when it was detected for the first time in the districts of Marcos Juárez and Jesús María, province of Córdoba. Since then, the disease has been rapidly expanding. This study was undertaken for the purpose of characterizing through a geographical information system (GIS) the areas where the disease was detected up to the present. Data were used for 28 sites where virosis was detected during the 2003-2006 period. FloraMap 1.02 software was used to characterize the sites. Maximum and minimum altitudes recorded were 1280 and 30 m above sea level respectively. Maximum and minimum average ambient temperatures (AAT) were 27.9ºC and 6.1ºC respectively. Maximum and minimum average environmental pressure (AEP) was 239 mm and 2 mm respectively. All sites had a dry season lasting from 6 to 11 months. These results will contribute to an epidemiological study by providing data on climatic features.Peer reviewe

Transmisión experimental de geminivirus por Bemisia tabaci a diferentes cultivares de poroto

Trabajo presentado al XXXII Congreso Argentino de Horticultura, celebrado del 23-26 de septiembre 2009, en Salta, Argentina.Peer reviewe

Especies nativas e introducidas del complejo Bemisia tabaci en cultivos de batata de Argentina

Sweet potato (Ipomoea batatas (L.) Lam) is one of the most important crops worldwide. Recently, the appearance of severe viral symptoms has been observed in sweet potato crops in the pampas region of Argentina and both begomovirus and crinivirus, exclusively transmitted by whiteflies, have been identified. The aim of this study was to identify B. tabaci species from sweet potato crops in Colonia Caroya by analysing mitochondrial cytochrome c oxidase subunit I (mtCOI) sequences. Two previously described haplotypes were identified: New World2 (indigenous species) and MEAM1 (introduced species). The results indicate the presence of both species, which are potential vectors of begomovirus and crinivirus in Argentina.La batata (Ipomoea batatas (L.) Lam) es uno de los cultivos más importantes en el mundo. Recientemente se observó una severa sintomatología viral en cultivos de la región pampeana argentina, en la que están identificados begomovirus y crinivirus, ambos transmitidos exclusivamente por mosca blanca. El objetivo de este estudio fue identificar las especies de B. tabaci en cultivos de batata en Colonia Caroya, mediante el análisis de secuencias mitocondriales de la citocromo oxidasa subunidad I (mtCOI). Se identificaron dos haplotipos (especies crípticas) ya descriptos en el mundo: New World2 (especie nativa) y MEAM1 (especie introducida). Los resultados indican la presencia de ambas especies, las cuales son potenciales vectores de begomovirus y crinivirus en batata en Argentina

Relative preliminary study to the caracterization of the resistance to Bemisia tabaci (Hemiptera: Aleyrodidae) in bean

Trabajo presentado al XL Annual Meeting of the Brazilian Phytopathological Society - XL Congresso Brasileiro de Fitopatologia, celebrado del 13-17 de agosto 2007, en Maringá, Brasil.La mosca blanca B. tabaci es una limitante en la producción de poroto, principal cultivo extensivo del noroeste argentino. Dentro del manejo integrado de plagas se destaca la resistencia de la planta hospedante, que brinda una solución práctica y de menor costo. Se intentó detectar y caracterizar preliminarmente los mecanismos de resistencia a B. tabaci en siete cultivares de poroto (Borlotti Bush, Borlotti Clio, Borlotti Lengua de Fuego, Cannellini, Light Red Kidney, Gateado y Alubia (control susceptible). Se empleó una población de moscas de la provincia de Corrientes-Argentina, caracterizadas molecularmente (RAPD) como biotipo B. Se determinaron variables indicadoras de antibiosis (tasa de mortalidad, número de huevos, ninfas y adultos) y de antixenosis (área total e intensidad de las manchas de las excreciones del insecto) bajo condiciones de no escogencia. La cuantifi cación de huevos, ninfas y adultos teniendo en cuenta la tasa de mortalidad, indican que el cultivar más susceptible para B. tabaci es Alubia y los más resistentes son B. Bush, B. Clio, L. R. K. En cuanto a la antixenosis, Cannellini y L. R. K. fueron los genotipos más susceptibles y B. Lengua de Fuego, el más resistente.Peer reviewe