DOCSLIB.ORG

An Analysis of Viruses Associated with Cassava Mosaic Virus Disease in Three Angolan Provinces S

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
An Analysis of Viruses Associated with Cassava Mosaic Virus Disease in Three Angolan Provinces S An analysis of viruses associated with cassava mosaic virus disease in three Angolan provinces S. Matic, A.T. Pais da Cunha, Jeremy R. Thompson, Mark Tepfer To cite this version: S. Matic, A.T. Pais da Cunha, Jeremy R. Thompson, Mark Tepfer. An analysis of viruses associated with cassava mosaic virus disease in three Angolan provinces. Journal of Plant Pathology, Springer, 2012, 94 (2), pp.443-450. 10.4454/JPP.FA.2012.043. hal-01191289 HAL Id: hal-01191289 https://hal.archives-ouvertes.fr/hal-01191289 Submitted on 29 May 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution - ShareAlike| 4.0 International License 021_JPP1146SC(Matic)_443 20-07-2012 10:16 Pagina 443 Journal of Plant Pathology (2012), 94 (2), 443-450 Edizioni ETS Pisa, 2012 443 SHORT COMMUNICATION AN ANALYSIS OF VIRUSES ASSOCIATED WITH CASSAVA MOSAIC DISEASE IN THREE ANGOLAN PROVINCES S. Matic1,2*, A.T. Pais da Cunha3,4, J.R. Thompson1,5 and M. Tepfer1,6,7 1Plant Virology Group, ICGEB Biosafety Outstation, Via Piovega 23, 31056 Ca’Tron di Roncade, Italy 2Istituto di Virologia Vegetale, CNR, Strada delle Cacce 73, 10135 Torino, Italy 3Dipartimento Territorio e Sistemi Agro-Forestali - Patologia Vegetale, Università degli Studi di Padova, Agripolis, Viale dell’Università, 16, 35020 Legnaro (PD), Italy 4Departamento de Agronomia - Instituto Superior Politécnico do Kwanza sul, Rua 12 Novembro, Sumbe, Angola 5Department of Plant Pathology and Plant-Microbe Biology, 334 Plant Science Building, Cornell University, Ithaca, NY 14853, USA 6INRA, UMR1318, Institut Jean-Pierre Bourgin, INRA-Versailles 78026 Versailles cedex, France 7INRA, UR407, Station de Pathologie Végétale, INRA-Avignon, 84140 Montfavet cedex, France *Present address: Centre for Agro-Environmental Innovation (AGROINNOVA), Università degli Studi di Torino, Via Leonardo da Vinci 44, 10095 Grugliasco (TO), Italy SUMMARY (Briddon and Markham, 1995). The majority of bego- moviruses have bipartite genomes, termed DNA-A and Seventeen cassava plants showing strong cassava mo- DNA-B (Stanley et al., 2004). The most recent taxo- saic disease symptoms were sampled from three Angolan nomic approach recognises seven African cassava mosa- provinces. The DNA-A component of two isolates was ic geminivirus species: African cassava mosaic virus amplified by rolling circle amplification (RCA) and char- (ACMV), East African cassava mosaic virus (EACMV), acterized. The complete DNA-A of 2,778 nucleotides East African cassava mosaic Cameroon virus (EACMCV), from sample AOS showed very high similarity to African East African cassava mosaic Kenya virus (EACMKV), cassava mosaic virus (ACMV), and that of 2,799 nu- East African cassava mosaic Malawi virus (EACMMV), cleotides from sample AO7 showed high identity to East East African cassava mosaic Zanzibar virus (EACMZV), African cassava mosaic virus (EACMV), particularly to and South African cassava mosaic virus (SACMV) (Fau- EACMV-Uganda2 Severe strain. This represents the first quet et al., 2008). report of complete ACMV and EACMV DNA-A se- After the first report of the severe form of CMD in quences from Angola. PCR followed by direct sequenc- Uganda, a novel recombinant begomovirus named ing of PCR products of a portion of DNA-A and DNA-B EACMV-Uganda2 Severe, which we will abbreviate as detected ACMV or EACMV in all 17 cassava plants. EACMV-UG, has been associated with the severe CMD None of the five other cassava mosaic virus species were pandemic (Deng et al., 1997; Zhou et al., 1997). found. The presence of a mixed infection of ACMV and EACMV-UG was found either singly or in mixed infec- EACMV-Uganda2 Severe strain, associated with cassava tion with ACMV (Harrison et al., 1997; Pita et al., 2001; mosaic disease pandemic, highlights the need for stricter Ntawuruhunga et al., 2007). The EACMV-UG genome controls on the importation of infected cassava stem cut- is distinguished from that of other EACMV strains by tings from neighbouring countries and further investiga- the presence of a region in the coat protein (CP) AV1 tions on the sanitary status of cassava plants in the gene of ca. 500 bp with high sequence identity to the presently unsurveyed provinces of Angola. corresponding part of the ACMV genome. Angola is one of the biggest cassava producers in Key words: Begomovirus, RCA, DNA sequencing, southern Africa. Food security of the country is influ- phylogenetic analyses. enced by the success of cassava production, which is di- rectly related with the presence of CMD and crop pro- Cassava mosaic disease (CMD) is the most important tection programmes. To our knowledge, there are only viral disease affecting cassava (Manihot esculenta two reports on viruses associated with CMD in Angola. Crantz) in Africa (Thresh et al., 1994; Legg et al., 2006). The presence of EACMV from one cassava plant in CMD is caused by several whitefly-transmitted viruses southern Angola (Okavango region) was reported by belonging to the genus Begomovirus (family Geminiviri- Berry and Rey (2001). More recently, using ELISA and dae) which have circular, single-stranded DNA genomes species-specific PCR, ACMV was determined to be the predominant species, followed by EACMV and EACMV-UG from the Cuanza Norte, Malanje and Uige Corresponding author: S. Matic Fax: +39.011.6709307 provinces of Angola (Lava Kumar et al., 2008). Despite E-mail: [email protected]; [email protected] these studies, there is still a lack of data regarding the 021_JPP1146SC(Matic)_443 20-07-2012 10:16 Pagina 444 444 Viruses associated with cassava mosaic disease in Angola Journal of Plant Pathology (2012), 94 (2), 443-450 molecular characterization and genomic variability of EcoRI and BamHI (New England Biolabs, USA). A these viruses in the country, which would greatly assist fragment of approximately 2.8 kb was amplified from in the development of control strategies. The objective all Angolan samples, the size expected for the DNA-A of this study was to analyze the presence of viruses in of begomoviruses. The 2.8 kb-band from sample AOS cassava plants exhibiting CMD symptoms, and to esti- (obtained with EcoRI) and AO7 (obtained with BamHI) mate the genetic diversity among the virus isolates asso- was excised and purified using the QIAquick Gel Ex- ciated with the disease in three Angolan provinces. traction Kit (Qiagen, USA). Purified products were Seventeen cassava plants showing strong CMD symp- cloned into the EcoRI or BamHI site of a previously di- toms were sampled from farms in Cabo Ledo (Bengo gested pBluescript KS (+) vector (Stratagene, USA), province), Canjala (Benguela province), and Porto-Am- then transformed into Escherichia coli DH5α cells by boim, Sumbe and Uku Seles (Cuanza Sul province) dur- electroporation. Plasmids containing the desired inserts ing January 2009 (Table 1, Fig. 1). CMD symptoms were extracted by Jetprep Plasmid Miniprep Kit were observed in all surveyed orchards. Plants were (Genomed GmbH, Germany). DNA sequences of the stunted, and leaves were mottled, distorted, and smaller. selected recombinant plasmids were obtained by auto- Samples were taken from different native and imported matic sequencing at BMR (Padova, Italy). Multiple se- cultivars, such as Precose de Angola, Mundele Paço, quence alignment of nucleotide (nt) and amino acid (aa) Ngana rico, Thiti, TMS 30142, and TMS 40125. sequences and identification of open reading frames Total nucleic acid (TNA) was extracted from 100 mg (ORFs) were done using the program AlignX (Vector of tissue (leaf or phloem scrapings) according to Foissac NTI Suite V 5.5, InforMax, USA) with the Clustal W et al. (2001). Circular DNA was amplified using the Il- algorithm (Thompson et al., 1994). Detection of possi- lustra TempliPhi 100 Amplification Kit (GE Healthcare, ble recombinants was carried out using the RDP3 pro- USA) following the manufacturer’s instructions. RCA gram (Martin et al., 2010). Phylogenetic analysis was products were digested by the restriction endonucleases performed using PAUP 4.0 (Swofford, 2001), with the Fig. 1. A map of Angola showing the localities in Bengo, Cuanza Sul and Benguela provinces where cassava plants were sampled. 021_JPP1146SC(Matic)_443 20-07-2012 10:16 Pagina 445 Journal of Plant Pathology (2012), 94 (2), 443-450 Matic et al. 445 Table 1. Angolan cassava isolates used for molecular characterization by RCA and PCR. ACMV EACMV Isolate Accession No. Accession No. Accession No. Accession No. Province code DNA-A DNA-B DNA-A DNA-B (AC2/AC1) (BV1/BC1) (AC2/AC1) (BC1) AO1 Bengo GU580899 AO2 Bengo GU580900 GU580925 AO3 Bengo GU580901 GU580915 GU580926 AO4 Bengo GU580911 AO5 Bengo GU580902 GU580916 GU580927 AO7 Bengo GU580903 JN941177* AO9 Bengo GU580904 AO10 Bengo GU580905 AOUN Benguela GU580910 GU580934 AOA Cuanza Sul GU580906 GU580917 GU580928 AOE Cuanza Sul GU580918 GU580912 GU580929 AOH Cuanza Sul GU580907 GU580919 GU580930 AOJ Cuanza Sul GU580908 GU580920 AOK Cuanza Sul GU580921 GU580913 GU580931 AON Cuanza Sul GU580909 GU580922 GU580932 AOO Cuanza Sul GU580923 GU580914 GU580933 AOS Cuanza Sul GU580897* GU580924 *Sequences in bold were obtained by RCA and subsequent cloning, all other sequences were obtained by PCR. best model being selected by qModeltest (Posada, AOS clone (accession No. GU580897) revealed a very 2009). high identity to ACMV DNA-A, showing the highest nt A set of primers (ACMV21for and ACMV21rev) was identity (96%) with an ACMV isolate from Uganda designed for the detection of all known African cassava (ACMV-[UG:Mpi:56:02], accession No. AM502339).
Load more

Recommended publications
  • Novel Ampeloviruses Infecting Cassava in Central Africa and the South-West Indian Ocean Islands
    viruses Article Novel Ampeloviruses Infecting Cassava in Central Africa and the South-West Indian Ocean Islands Yves Kwibuka 1,2,* , Espoir Bisimwa 2, Arnaud G. Blouin 1, Claude Bragard 3 , Thierry Candresse 4 , Chantal Faure 4, Denis Filloux 5,6, Jean-Michel Lett 7 , François Maclot 1, Armelle Marais 4, Santatra Ravelomanantsoa 8 , Sara Shakir 9 , Hervé Vanderschuren 9,10 and Sébastien Massart 1,* 1 Plant Pathology Laboratory, TERRA-Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés, 2, 5030 Gembloux, Belgium; [email protected] (A.G.B.); [email protected] (F.M.) 2 Faculté des Sciences Agronomiques, Université Catholique de Bukavu, BP 285 Bukavu, Democratic Republic of the Congo; [email protected] 3 Earth and Life Institute, Applied Microbiology-Phytopathology, UCLouvain, 1348 Louvain-la-Neuve, Belgium; [email protected] 4 Université Bordeaux, INRAE, UMR BFP, CS20032, CEDEX, 33882 Villenave d’Ornon, France; [email protected] (T.C.); [email protected] (C.F.); [email protected] (A.M.) 5 CIRAD, UMR PHIM, 34090 Montpellier, France; denis.fi[email protected] 6 PHIM Plant Health Institute, Université Montpellier, CIRAD, INRAE, Institut Agro, IRD, 34000 Montpellier, France 7 CIRAD, UMR PVBMT, Pôle de Protection des Plantes, Saint-Pierre, F-97410 Ile de la Reunion, France; [email protected] 8 FOFIFA-CENRADERU, Laboratoire de Pathologie Végétale, BP 1444 Ambatobe, Madagascar; [email protected] 9 Plant Genetics Laboratory, TERRA-Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés, 2, Citation: Kwibuka, Y.; Bisimwa, E.; 5030 Gembloux, Belgium; [email protected] (S.S.); [email protected] (H.V.) Blouin, A.G.; Bragard, C.; Candresse, 10 Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, Biosystems Department, T.; Faure, C.; Filloux, D.; Lett, J.-M.; KU Leuven, 3000 Leuven, Belgium Maclot, F.; Marais, A.; et al.
    [Show full text]
  • Controlling Cassava Mosaic Virus and Cassava Mealybug in Sub-Saharan Africa
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Research Papers in Economics IFPRI Discussion Paper 00912 November 2009 Controlling Cassava Mosaic Virus and Cassava Mealybug in Sub-Saharan Africa Felix Nweke 2020 Vision Initiative This paper has been prepared for the project on Millions Fed: Proven Successes in Agricultural Development (www.ifpri.org/millionsfed) INTERNATIONAL FOOD POLICY RESEARCH INSTITUTE The International Food Policy Research Institute (IFPRI) was established in 1975. IFPRI is one of 15 agricultural research centers that receive principal funding from governments, private foundations, and international and regional organizations, most of which are members of the Consultative Group on International Agricultural Research (CGIAR). FINANCIAL CONTRIBUTORS AND PARTNERS IFPRI’s research, capacity strengthening, and communications work is made possible by its financial contributors and partners. IFPRI receives its principal funding from governments, private foundations, and international and regional organizations, most of which are members of the Consultative Group on International Agricultural Research (CGIAR). IFPRI gratefully acknowledges the generous unrestricted funding from Australia, Canada, China, Finland, France, Germany, India, Ireland, Italy, Japan, Netherlands, Norway, South Africa, Sweden, Switzerland, United Kingdom, United States, and World Bank. MILLIONS FED “Millions Fed: Proven Successes in Agricultural Development” is a project led by IFPRI and its 2020 Vision Initiative to identify interventions in agricultural development that have substantially reduced hunger and poverty; to document evidence about where, when, and why these interventions succeeded; to learn about the key drivers and factors underlying success; and to share lessons to help inform better policy and investment decisions in the future.
    [Show full text]
  • Some Aspects of the Epidemiology of African Cassava Mosaic Virus in Ivory Coast
    I r-1 j. _. TROPICAL PEST MANAGEMENT 1988 34flI 92-96 h:cIyfImi:'ms__- - 5cn,-- 'll'll. .- , - 'h . IS 5 - t" Some aspects of the epiaemiology of African cassava mosaic virus in Ivory Coast l (Keywords: Cassava. vws. whitefly, ACMV, epidemiology. Africa) 0 I ARGETTE, and L. C. HOUVENEL Laboratoire dP Virolope Vegetale. Institut1 Francars de Recherche Scientifique pour le Developpement en Cooperation P. (ORSTOM) B. V51. Abidjan, Ivory Coast Abstract. Re-infection of healthy cassava plants by African cassava epidemiological features and the overall ecology of ACMV in mosaic virus (ACMV) was followed in different varieties and tor different situations: several years at various locations in two regions of Ivory Coast. Whitefly populations on cassava and virus incidence varied widely between sites. even amongst those close to one another. However, for each location and in every year. the spread of ACMV showed the same general trend Little spread occurred at Toumodi ín the Savannah region which IS outside the main cassava production area. Much greater spread occurred at a nearby site and at all sites in the forest region except one alongside the Ocean where there were no cassava plantings upwind. Among sites there was no direct relation between virus incidence and the total number of adult whitefly, whereas there was a relationship between spread and the occuir- ence of .nfected cassava upwind although not necessarily close by. Introduction African cassava mosaic disease is one of the most important factors limiting the production of cassava (Manihot esculenla Crantz) in Africa. The disease is caused by a gentnivirus (ACMV), which aflects nearly all the cassava plants grown.
    [Show full text]
  • A New Type of Satellite Associated with Cassava Mosaic Begomoviruses
    bioRxiv preprint doi: https://doi.org/10.1101/2021.03.11.434950; this version posted March 11, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Aimone et al. A New Type of Satellite associated with Cassava Mosaic Begomoviruses Catherine D. Aimone1*, Leandro De León2#, Mary M. Dallas1, Joseph Ndunguru3, José T. Ascencio-Ibáñez2, Linda Hanley-Bowdoin1* 1Department of Plant and Microbial Biology, North Carolina State University, Raleigh NC 27695 USA 2Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh NC 27695 USA 3 Tari Selian, Arusha, Tanzania Running Head: A novel begomovirus satellite #Current address: Department of Biochemistry, Microbiologyy, Cell Biology and Genetics, Universidad de La Laguna, S/C de Tenerife 38200 Spain *Address correspondence to Catherine D. Aimone, [email protected] 1 bioRxiv preprint doi: https://doi.org/10.1101/2021.03.11.434950; this version posted March 11, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Aimone et al. Abstract Cassava mosaic disease (CMD), which is caused by single-stranded DNA begomoviruses, severely limits cassava production across Africa. A previous study showed that CMD symptom severity and viral DNA accumulation increase in cassava in the presence of a DNA sequence designated as SEGS-2 (sequence enhancing geminivirus symptoms). We report here that when SEGS-2 is co-inoculated with African cassava mosaic virus (ACMV) onto Arabidopsis thaliana, viral symptoms increase.
    [Show full text]
  • Alternative Hosts of Cassava Viruses in Kaduna and Sokoto States, Nigeria
    Science World Journal Vol. 15(No 2) 2020 www.scienceworldjournal.org ISSN 1597-6343 Published by Faculty of Science, Kaduna State University ALTERNATIVE HOSTS OF CASSAVA VIRUSES IN KADUNA AND SOKOTO STATES, NIGERIA 1* 2 2 2 H. Badamasi , M. D. Alegbejo , B. D. Kashina and O. O. Banwo Full Length Research Article 1Pest Management Programme, Samaru College of Agriculture, Division of Agricultural Colleges, Ahmadu Bello University, Zaria 2Crop Protection Department, Faculty of Agriculture, Ahmadu Bello University, Zaria Corresponding Author’s Email Address: [email protected] Phone: +23481758383230 ABSTRACT Gemini-viruses (CMGs) (Legg et al., 1992) and they transmit at Field surveys were conducted in 2015 wet and 2016 dry seasons least 21 viruses in Nigeria (Alegbejo, 2000). In Nigeria, natural to determine the occurrence of alternative hosts of cassava host and weed hosts of CaMV have been reported with viruses in Kaduna and Sokoto States, Nigeria. Eighteen farms occurrence of Cassava mosaic disease (CMD) on originally from six local Government Areas namely; Lere, Chikun, Kajuru healthy cassava crop associated with weed hosts has been (Kaduna State), Tureta, Shagari and Tambuwal (Sokoto State) reported (Hillocks, 2003). No weed host(s) for Cassava Congo were surveyed. Fifty- four weed samples within and around the Sequivirus was reported. However, Secundina plant was used as farms were collected; Eighteen weeds were identified in wet an experimental host for members of family Sequiviridae (Wilmer season while 19 weeds were collected and 18 were identified et al., 2015). Therefore, the needs to detect the presence of during dry season. Three viruses were tested; African cassava ACMV, EACMV and Cassava Congo sequivirus on non-cassava mosaic virus (ACMV), East African cassava mosaic virus plants is necessary in order to fill the gap that exist.
    [Show full text]
  • The Viruses and Virus Diseases of Cassava
    Color profile: Disabled Composite Default screen Chapter 12 The Viruses and Virus Diseases of Cassava L.A. Calvert1 and J.M. Thresh2 1Centro Internacional de Agricultura Tropical (CIAT), A.A. 6713, Cali, Colombia; 2Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK Introduction A feature of cassava viruses is that they are of diverse taxonomic groups (Table 12.1). Crops that are propagated vegetatively are Another is that their known distribution is particularly prone to damage by viruses as largely or entirely restricted to only one of the infection tends to build up in successive cycles continents in which cassava is grown, or to an of propagation. Cassava is no exception to this even more localized geographic area. For this generalization and at least 16 different viruses reason the viruses and virus diseases of Africa, have been isolated from the crop. Moreover, South/Central America and the Indian sub- other as yet undescribed viruses are likely to continent are considered separately. occur and may even be prevalent in some areas. This is because cassava has received far less attention from virologists than it merits as one of the world’s most important and widely grown The Viruses and Virus Diseases food crops. of Cassava in South and A full list of the viruses that have been Central America isolated from cassava is presented in Table 12.1 and key references appear in the bibliography. Cassava originated in the Neotropics and was The viruses asterisked in the table have been not introduced to other regions until relatively detected somewhat fortuitously in studies under- recently.
    [Show full text]
  • Molecular Evidence for the Association of a Strain of Uganda Variant of East African Cassava Mosaic Virus to Symptom Severity In
    American Journal of Biochemistry and Biotechnology 5 (4): 196-201, 2009 ISSN 1553-3468 © 2009 Science Publications Molecular Evidence for the Association of a Strain of Uganda Variant of East African Cassava Mosaic Virus to Symptom Severity in Cassava (Manihot esculenta Crantz) Fields in Togo 1K.D. Adjata, 2E. Muller, 2M. Peterschmitt, 3O. Traoré and 1Y.M.D. Gumedzoe 1Laboratory of Plant Virology and Biotechnology, High School of Agronomy, University of Lome, B.P. 1515, Lomé, Togo 2Biology and Genetics of Plant-Pathogen Interactions for Integrated Protection, (CIRAD-UMR BGPI) TA 41/K, International Campus of Baillarguet, 34398 Montpellier Cedex 5, France 3Institute of Environment and Agricultural Research, 01 BP 476, Ouagadougou 01, Burkina Faso Abstract: Problem statement: This study was carried out to demonstrate that the severity of Cassava Mosaic Disease (CMD) in Togo, is not only influenced by synergism between cassava Begomoviruses in presence, but essentially by recombination between the different Begomoviruses infecting cassava. Approach: Foliar samples presenting typical biological features of Begomoviruses infection were collected from cassava and wild infected plants from different regions of Togo and analysed by PCR targeting the Coat Protein (CP). The PCR products obtained from different isolates of two major Begomoviruses species infecting cassava in Togo were then sequenced and compared with the sequenced of the African cassava mosaic Begomoviruses identified to date and available in NCBI GenBank database by phylogenetic analysis. Results: The results indicate that not only the two major Begomoviruses could be in synergistic interaction in infected cassava in Togo as it has been shown between African Cassava Mosaic Virus (ACMV) and East African Cassava Mosaic Virus (EACMV) elsewhere, but could also create recombinants which would be highly interfering in the development of symptom severity in the country.
    [Show full text]
  • Incidence and Severity of Cassava Mosaic Disease in the Republic of Congo
    African Crop Science Journal, Vol. 15, No. 1, pp. 1 - 9 ISSN 1021-9730/2007 $4.00 Printed in Uganda. All rights reserved ©2007, African Crop Science Society INCIDENCE AND SEVERITY OF CASSAVA MOSAIC DISEASE IN THE REPUBLIC OF CONGO P. NTAWURUHUNGA, G. OKAO-OKUJA, A. BEMBE1, M. OBAMBI2, J. C. ARMAND MVILA1 and J.P. LEGG3 International Institute of Tropical Agriculture-Uganda, Kampala, Uganda 1Ministère de l’Enseignement Primaire, Secondaire et Supérieur, chargé de Recherche Scientifique et Technologique / Délégation Générale de la Recherche Scientifique et Technologique (DGRST), Brazzaville, République du Congo 2Ministère de l’Agriculture de l’Elevage, de la Pêche et de la Promotion Feminine, Brazzaville, République du Congo 3Natural Resources Institute, Chatham Maritime, Kent, United Kingdom and International Institute of Tropical Agriculture-Tanzania, Dar es Salaam, Tanzania (Received 29 December, 2006; accepted 19 March, 2007) ABSTRACT Diagnostic surveys were conducted in 2002 and 2003 in order to provide a comprehensive and detailed assess- ment of the status of cassava mosaic disease (CMD) in the Republic of Congo (ROC) and to determine if the disease was spreading. In 2002, 105 farmers’ fields were assessed in the four major cassava-producing regions of the country. In 2003, 163 fields were sampled in nine regions and Brazzaville Commune. Incidence of cassava mosaic disease was generally high, averaging 80 and 86 % for 2002 and 2003, respectively; while damage was moderate to severe. In 2002, disease incidence was moderate in Pool (73%) but high in Brazzaville (81%), Cuvette Centrale (82%) and in Plateaux Region (84%). Pool region still had the lowest incidence (78%) in 2003, while Sangha (95%) had the highest incidence.
    [Show full text]
  • 2011 Threats to Cassava Production.Pdf
    Editorial Manager(tm) for Food Security: The Science, Sociology and Economics of Food Production and Access to Food Manuscript Draft Manuscript Number: FOSE254R2 Title: Threats to cassava production: known and potential geographic distribution of four key biotic constraints Article Type: Original refereed paper Keywords: Cassava; whitefly; green mite; cassava mosaic disease; cassava brown streak disease; geographic distribution; ecological modeling Corresponding Author: Beatriz Vanessa Herrera Campo Corresponding Author's Institution: International Center for Tropical Agriculture First Author: Beatriz Vanessa Herrera Campo Order of Authors: Beatriz Vanessa Herrera Campo;Glenn Hyman;Anthony Bellotti Abstract: Insect pests and plant diseases reduce cassava yields substantially, posing a threat to food security throughout the developing world. While agricultural scientists have recognized these threats, few assessments of the geographic distribution of cassava pests and diseases have been made at the global scale. The goal of this study is to make such an evaluation for four key biotic constraints to cassava production in developing countries: whiteflies, cassava green mites, cassava mosaic disease and cassava brown streak disease. Occurrence records were obtained from laboratory and biodiversity databases and from the scientific literature. These records were then used in ecological niche models to predict the potential distribution of cassava pests and diseases. The distribution maps were cross- validated by holding back 20 percent of the occurrence records. Potential distribution maps were developed by combining the results of the best ecological niche models. Hotspots for potential cassava pest and disease outbreaks include the Mato Grosso in Brazil, northern South America, the African rift valley, the southern tip of India and much of Southeast Asia, where all four biotic constraints show high potential suitability.
    [Show full text]
  • MOLECULAR EVOLUTION and PHYLOGENETICS of CIRCULAR SINGLE-STRANDED DNA VIRUSES by YEE MEY SEAH a Dissertation Submitted To
    MOLECULAR EVOLUTION AND PHYLOGENETICS OF CIRCULAR SINGLE-STRANDED DNA VIRUSES By YEE MEY SEAH A dissertation submitted to the Graduate School-New Brunswick Rutgers, The State University of New Jersey And The Graduate School of Biomedical Sciences In partial fulfillment of the requirements For the degree of Doctor of Philosophy Graduate Program in Microbiology and Molecular Genetics Written under the direction of Siobain Duffy And approved by _____________________________________ _____________________________________ _____________________________________ _____________________________________ New Brunswick, New Jersey October, 2015 ABSTRACT OF THE DISSERTATION Molecular Evolution and Phylogenetics of Circular Single-stranded DNA Viruses by YEE MEY SEAH Dissertation Director: Siobain Duffy, Ph.D. Viruses infect a wide variety of hosts across all domains of life. Despite their ubiquity, and a long history of virus research, fundamental questions such as what constitutes a virus species, and how viruses evolve and are modeled, have yet to be adequately answered. We compared viral sequences across five genomic architectures (single- and double-stranded DNA and RNA) and demonstrate the presence of substitution bias, especially in single-stranded viruses. Most striking is a consistent pattern of over-represented cytosine-to- thymine substitutions in single-stranded DNA (ssDNA) viruses. This led us to question the validity of using time-reversible nucleotide substitution models in viral phylogenetic inference, as these models assume equal rates of forward and reverse substitutions. We found that an unrestricted substitution model fit the data better for most single- and double-stranded viral datasets, as measured by corrected Akaike Information Criterion, and hierarchical likelihood ratio test scores. We also approached the question of virus species identification by examining members of the most species-rich viral genus Begomovirus (Family ii Geminiviridae), which are circular single-stranded DNA (ssDNA) viral crop pathogens transmitted by whitefly vectors.
    [Show full text]
  • Gates Open Research Gates Open Research 2018, 1:16 Last Updated: 15 MAY 2019
    Gates Open Research Gates Open Research 2018, 1:16 Last updated: 15 MAY 2019 RESEARCH ARTICLE The first transcriptomes from field-collected individual whiteflies (Bemisia tabaci, Hemiptera: Aleyrodidae) [version 2; peer review: 1 approved, 1 approved with reservations] Peter Sseruwagi1*, James Wainaina2*, Joseph Ndunguru1, Robooni Tumuhimbise 3, Fred Tairo1, Jian-Yang Guo4,5, Alice Vrielink2, Amanda Blythe 2, Tonny Kinene 2, Bruno De Marchi 2,6, Monica A. Kehoe7, Sandra Tanz 2, Laura M. Boykin 2 1Mikocheni Agriculture Research Institute (MARI), Dar es Salaam, P.O. Box 6226, Tanzania 2School of Molecular Sciences and Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Perth, WA, 6009, Australia 3National Agricultural Research Laboratories, P.O. Box 7065, Kampala Kawanda - Senge Rd, Kampala, Uganda 4Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, 310058, China 5State Key Laboratory for the Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China 6Faculdade de Ciências Agronômicas, Universidade Estadual Paulista , Botucatu, Brazil 7Department of Primary Industries and Regional Development, DPIRD Diagnostic Laboratory Services, South Perth, WA, Australia * Equal contributors First published: 28 Dec 2017, 1:16 ( Open Peer Review v2 https://doi.org/10.12688/gatesopenres.12783.1) Second version: 13 Feb 2018, 1:16 ( https://doi.org/10.12688/gatesopenres.12783.2) Reviewer Status Latest published: 08 Mar 2018, 1:16 ( https://doi.org/10.12688/gatesopenres.12783.3) Invited Reviewers 1 2 Abstract Background: Bemisia tabaci species (B. tabaci), or whiteflies, are the world’s most devastating insect pests.
    [Show full text]
  • Identifying New Resistance to Cassava Mosaic Disease and Validating Markers for the CMD2 Locus
    agriculture Article Identifying New Resistance to Cassava Mosaic Disease and Validating Markers for the CMD2 Locus Cu Thi Le Thuy 1, Luis Augusto Becerra Lopez-Lavalle 2 , Nguyen Anh Vu 3, Nguyen Huu Hy 4, Pham Thi Nhan 4, Hernan Ceballos 2,† , Jonathan Newby 5 , Nguyen Ba Tung 4, Nguyen Trong Hien 6, Le Ngoc Tuan 3, Nguyen Hung 3, Nguyen Thi Hanh 3, Do Thi Trang 3, Pham Thi Thu Ha 6, Le Huy Ham 3,7, Xuan Hoi Pham 3, Do Thi Nhu Quynh 3, Ismail Y. Rabbi 8, Peter A. Kulakow 8 and Xiaofei Zhang 2,* 1 International Center for Tropical Agricultural (CIAT), Hanoi 100000, Vietnam; [email protected] 2 CGIAR Research Program on Roots Tubers and Bananas (RTB), International Center for Tropical Agriculture (CIAT), Cali 763537, Colombia; [email protected] (L.A.B.L.-L.); [email protected] (H.C.) 3 National Key Laboratory for Plant Cell Biotechnology, Agricultural Genetics Institute (AGI), Hanoi 100000, Vietnam; [email protected] (N.A.V.); [email protected] (L.N.T.); [email protected] (N.H.); [email protected] (N.T.H.); [email protected] (D.T.T.); [email protected] (L.H.H.); [email protected] (X.H.P.); [email protected] (D.T.N.Q.) 4 Hung Loc Agricultural Research Center (HLARC), Thong Nhat 810000, Vietnam; [email protected] (N.H.H.); [email protected] (P.T.N.); [email protected] (N.B.T.) 5 International Center for Tropical Agricultural (CIAT), Vientiane 1000, Laos; [email protected] 6 Root Crops Research and Development Center (RCRDC), Hanoi 100000, Vietnam; [email protected] (N.T.H.); [email protected] (P.T.T.H.) 7 Faculty of Agricultural Technology, University of Engineering and Technology, Hanoi 100000, Vietnam Citation: Thuy, C.T.L.; 8 International Institute for Tropical Agriculture (IITA), Ibadan 200001, Nigeria; [email protected] (I.Y.R.); Lopez-Lavalle, L.A.B.; Vu, N.A.; Hy, [email protected] (P.A.K.) N.H.; Nhan, P.T.; Ceballos, H.; Newby, * Correspondence: [email protected] † Former cassava breeders at the International Center for Tropical Agriculture (CIAT).
    [Show full text]