Detection and characterization of plant viruses on major food crops in togo (West Africa)
1. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO (WEST AFRICA). Y. Mawuena Dieudonné GUMEDZOE , Professor, Director of Research University of Lome/ Faculty of Agriculture/ Plant Virology & Biotechnology Lab (LVBV). B.P.1515 LOME TOGO FAX (228) 2218595 E-mail : [email_address] Member of the academies: AAS, TWAS
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12. 1. Coating ELISA plates with appropriate dilute antisera 2. Puting Antigens in place (Crushing samples in buffer and use the extracts) 3. Add conjugated antisera 4. Add susbtrat and stop the reaction when the yellow color appears III. DIAGNOSTIC TECHNIQUES(4) DIFFERENTS STEPS OF THE DAS-ELISA TEST Healthy Samples Infected Samples DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO
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14. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO. PLANT VIRUSES : DETECTION AND CHARACTERIZATION WHY ? FIRST STEPS FOR EPIDEMIOLOGICAL STUDIES IN ORDER TO DEVELOP STRATEGY TO CONTROL THEM. DIFFICULTIES : MORE DIFFICULT TO IDENTIFY AND CHARACTERIZE THAN OTHER PLANT PATHOGENS, REQUIRED ELABORATE AND EXPENSIVE EQUIPMENT AND REAGENTS , LACK OF EXPERTISE, INADEQUATE FUNDING AND FACILITIES IN SSA COUNTRIES. III. DIAGNOSTIC TECHNIQUES(6) WHY IS IT SO IMPORTANT TO DETECT AND CHARACTERIZE PLANT VIRUSES ? 1) They represent the first steps for epidemiological studies in order to develop control measures 2) During diseases surveys rapid diagnosis is needed 3) Important for plant quarantine and seed certification and also for plant breedimg programmes 4)Detection and characterization represent a vital task for plant virologists working in SSA countries.
15. DETECTION AND CHARACTERIZATION PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO. PLANT VIRUSES : DETECTION AND CHARACTERIZATION WHY ? FIRST STEPS FOR EPIDEMIOLOGICAL STUDIES IN ORDER TO DEVELOP STRATEGY TO CONTROL THEM. DIFFICULTIES : MORE DIFFICULT TO IDENTIFY AND CHARACTERIZE THAN OTHER PLANT PATHOGENS, REQUIRED ELABORATE AND EXPENSIVE EQUIPMENT AND REAGENTS , LACK OF EXPERTISE, INADEQUATE FUNDING AND FACILITIES IN SSA COUNTRIES. III.DIAGNOSTIC TECHNIQUES(5bis) DIFFICULTIES ENCOUNTERED DURING PLANT VIRUSES DETECTION / CHARACTERIZATION ? 1) Plants viruses are more difficult to identify than other plant pathogens 2) They require elaborate and expensive equipments and reagents 3) In most SSA countries there is a lack of critical scientific expertise 4) Inadequate research funding 5) Research facilities and other items (irregular power and water supplies) are not always available.
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17. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO IV. COLLABORATIVE PROJECTS(1) We are reporting here the results obtained during two collaborative projects: 1) A PILOT PROJECT ON COWPEA VIRUSES IDENTIFICATION WHICH HAVE INVOLVED SCIENTISTS FROM DEVELOPED AND DEVELOPING COUNTRIES AND ONE CENTRE OF CGIAR) (IITA).
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20. DETECTION AND CHARACTERIZATION PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO. IV COLLABORATIVE PROJECTS(4) B) ANTISERA AND PLANT MATERIALS USED DURING OUR STUDIES WERE FROM VRS OR IITA . C) METHODS 1)SURVEYS FOLIAR SAMPLES COLLECTED THROUGHOUT THE COUNTRY ON COWPEAS AND WEEDS (FARMERS’FIELDS/ EXPERIMENTAL PLOTS). 2) IDENTIFICATION OF VIRUSES SEROLOGY (DOUBLE DIFFUSION IN AGAROSE, ELISA AND PCR).
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22. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO IV. COLLABORATIVE PROJECTS : COWPEA VIRUSES(6) D) RESULTS (continued) BlCMV/ CAMV and their serotypes were identified on cowpea/ weeds. Acanthospermum hispidum ( serotypes F, G / CAMV B / BlCMV) Cassia occidentalis ( serotypes A,B/ BlCMV ) Passiflora foetida ( serotypes C,D/ CAMV ) Desmodium tortuosum ( serotypes C,D/CAMV ) Abutilon mauritianum ( serotypes C, E/CAMV ) Centrosema pubescens (serotypes C,F,G/ CAMV) Pupalia lappacea (serotypes: C,D,E,F/CAMV ).
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28. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO IV. COLLABORATIVE PROJECTS/ CASSAVA VIRUSES(12) TABLEAU 2 LIST OF POSITIVE CONTROLS USED Reference number DSMZ Origin Description PV-0421 Kenya ACMV-NG, Cassava infected leaves PV-0423 Kenya EACMV, Cassava infected leaves PV-0424 Sri Lanka ICMV, cassava infected leaves PV-0872/Ca-161 Cameroun EACMV, Cassava infected leaves
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31. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO (WEST AFRICA) IV. COLLABORATIVE PROJECTS/CASSAVA VIRUSES(15) TABLEAU1 : SPECIFIC PRIMERS USED FOR THE IDENTIFICATION OF ACMV, EACMV, AND ICMV PRIMER SEQUENCE(5’ 3’) TARGET REGION JSP001 ATGTCGAAGCGACCAGGAGAT 5’ACMV/ EACMV CP JSP002 TGTTTATTAATTGCCAATACT 3’ACMV CP JSP003 CCTTTATTA ATT TGTCACTGC 3’EACMVCP JSP012 GTCCATATAGGTAARGTNATG 5’ICMV CP JSP013 CCTGCTCCTTGCTNGCYTART 3’ICMV CP
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37. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO IV. COLLABORATIVE PROJECTS /Cassava Viruses (21) C) RESULTS (CONTINUED) IDENTIFICATION OF ICMV BY PCR
38. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO. TABLE NUCLEOTIDE SEQUENCE OF PAIRWISE COMPARISON OF EACMV/ICMV FROM GENBANK AND EU155147, EU1551478,EU155149 (EACMV) AND EU152125 (ICMV)FROM TOGO . (22) 92 61 61 61 ICMV EU152125 67 80 81 81 EACMV EU155149 71 96 96 96 EACMV EU155148 72 93 93 93 EACMV EU155147 ICMV AJ314739 Sri Lanka EACMV AY562424 Kenya EACMV AJ717534 Kenya EACMV AF423178 Uganda EACMV/ ICMV-TG
39. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO `IV.COLLABORATIVE `PROJECTS (23)/ ``C) Results `(continued) `Cassava `Viruses `: Distribution `of `cassava/ `Begomoviruse``s in Togo.
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42. DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO IV. COLLABORATIVE PROJECTS D) LESSONS LEARNT FROM THESE PROJECTS(cont.)(26) 5) NETWORKING SCIENTISTS, CGIAR CENTRES, DEVELOPED,DEVELOPPING COUNTRIES. 6) KEY OF SUCCESS CGIAR centres NARS(universities, research centres in developing countries ) NARS (developed countries ) 7) OTHER COLLABORATIVE PROJECTS ON PLANT VIRUSES DETECTION / CHARACTERIZATION a) Cassava Begomoviruses (Fargette et al.1985, 1988) b) TSWV (CHO et al. 1989)
43. V. OTHER PLANT VIRUSES UNDER STUDIES IN OUR LAB 1) RICE RICE YELLOW MOTTLE VIRUS (RYMV) 2) TOMATOES TOMV, TSWV AND TYLCV 3) YAM POTYVIRUSES YAM MOSAIC VIRUS (YMV) AND YAM MILD MOSAIC VIRUS (YMMV) IDENTIFIED DETECTION AND CHARACTERIZATION OF PLANT VIRUSES ON MAJOR FOOD CROPS IN TOGO YMV RYMV