New Disease Reports
New Disease Reports (2009) 19, 21.
Next > < Prev

Occurrence of East African cassava mosaic virus-Uganda (EACMV-UG) in Burkina Faso

F. Tiendrébéogo 1,2, P. Lefeuvre 2, M. Hoareau 2, V.S.E. Traoré 3, N. Barro 1, B. Reynaud 2, A.S. Traoré 1, G. Konaté 3, O. Traoré 3 and J.-M. Lett 2*

*lett@cirad.fr

Show affiliations

Accepted: 25 Mar 2009

Cassava (Manihot esculenta) is a major staple food crop cultivated throughout Africa, and is affected most severely by cassava mosaic disease (CMD) occurring at high incidence throughout the continent. CMD is caused by cassava mosaic geminiviruses (CMGs) belonging to the genus Begomovirus (family Geminiviridae). The complex of CMGs include seven African species; the three main species are: African cassava mosaic virus (ACMV), East African cassava mosaic virus (EACMV) and South African cassava mosaic virus (SACMV) (Bull et al., 2006). In Uganda, an extremely severe epidemic of CMD has developed since the 1990s and has progressed since then in Uganda’s neighbouring countries and Central Africa. The severe CMD phenotype is caused by the synergistic interaction between ACMV and a distinct recombinant strain EACMV-UG, commonly known as the Uganda variant. CMD is reported to be widespread in Burkina Faso (Konaté et al., 1995), but the molecular features of the causal agent have never been investigated.

In August/September 2008, leaves were collected from cultivars of local cassava presenting moderate to severe CMD symptoms from the central region around Ouagadougou. Ten leaf samples were tested and found to be positive for the presence of begomoviruses by PCR, using degenerate primers VD360 and CD1266 (Delatte et al., 2005). For two of these samples, complete DNA-A genomes were cloned using the Phi29 DNA polymerase-based rolling circle amplification strategy (Inoue-Nagata et al., 2004) and sequenced by Macrogen Inc (Korea). One sequence (EMBL-GenBank-DDBJ Accession No. FM877473) showed 97% highest nucleotide identity with ACMV-[Ivory Coast:1999] (AF259894) and ACMV-[Nigeria:Ogoroco:1990] (AJ427910). The second sequence (FM877474) showed 98% nucleotide identity with EACMV-UG [Uganda:Severe2:1997] (AF126806). These results show that both species ACMV and EACMV-UG affect cassava plantings in Burkina Faso, and suggest a potential risk of the occurrence of a severe epidemic of CMD as in East Africa. To our knowledge, this is the first report of the Uganda variant in West Africa.

Figure1+
Figure 1: Cassava mosaic disease symptoms observed on a cultivar of local cassava infected with EACMV-UG in Koubri locality, Burkina Faso
Figure 1: Cassava mosaic disease symptoms observed on a cultivar of local cassava infected with EACMV-UG in Koubri locality, Burkina Faso
Figure2+
Figure 2: Maximum likelihood tree based on the complete DNA-A sequences of Burkina Faso isolates of African cassava mosaic virus-[Burkina Faso:Kamboinse:2008] and East African cassava mosaic virus-Uganda [Burkina Faso:Koubri:2008] reported here (in bold), plus additional sequences from African CMGs and the monopartite TYLCV-Mld used as outgroup. The numbers associated with the nodes indicate the percentage of bootstrap support (1000 replicates). The GenBank accession numbers are indicated in parentheses.
Figure 2: Maximum likelihood tree based on the complete DNA-A sequences of Burkina Faso isolates of African cassava mosaic virus-[Burkina Faso:Kamboinse:2008] and East African cassava mosaic virus-Uganda [Burkina Faso:Koubri:2008] reported here (in bold), plus additional sequences from African CMGs and the monopartite TYLCV-Mld used as outgroup. The numbers associated with the nodes indicate the percentage of bootstrap support (1000 replicates). The GenBank accession numbers are indicated in parentheses.

Acknowledgements

This research was funded by the following institutions: CRSBAN/UFR-SVT (University of Ouagadougou), INERA (CNRST, Burkina Faso), Conseil Régional de

References

  1. Bull SE, Briddon RW, Sserubombwe WS, Ngugi K, Markham PG, Stanley J, 2006. Genetic diversity and phylogeography of cassava mosaic viruses in Kenya. Journal of General Virology 87, 3053-3065.
  2. Delatte H, Martin DP, Naze F, Golbach RW, Reynaud B, Peterschmitt M, Lett JM, 2005. South West Indian Ocean islands tomato begomovirus populations represent a new major monopartite begomovirus group. Journal of General Virology 86, 1533–1542.
  3. Inoue-NagataAK, Albuquerque LC, Rocha WB, Nagata T, 2004. A simple method for cloning the complete begomovirus genome using the bacteriophage φ29 DNA polymerase. Journal of Virological Methods 116, 209–211.
  4. Konaté G, Barro N, Fargette D, Swanson MM, Harrison BD, 1995. Occurrence of whitefly-transmitted geminiviruses in crops in Burkina Faso and their serological detection and differentiation. Annals of Applied Biology 126, 121-129.
This report was formally published in Plant Pathology

©2009 The Authors