1 CIRAD, UMR PVBMT CIRAD-Université de La Réunion, Pôle de Protection des Plantes, Ligne Paradis, 97410 Saint-Pierre, La Réunion, France 2 INRAPE-DECVAS, BP1406, Moroni, Grande-Comore, Union des Comores
Accepted: 06 Jan 2006
In March 2004, within the Regional Program of Plant Protection, an
inventory of plant pathogens was organised in the Comoros Archipelago,
located in the northern part of the Mozambique Channel. Symptoms of leaf
curling and yellowing (Fig. 1) were observed on tobacco plants in the
Grande-Comore Island; the most northern Island of the Archipelago and
the closest to the African continent.
Leaf samples from tobacco plants
presenting the most severe symptoms, were collected from three different
locations: Foumboudzivouni (eastern region), Foumbouni (southeast
region) and Simboussa (southern region). Samples were conserved by
dehydration and tested for the presence of begomoviruses using
polymerase chain reaction (PCR) assays with two sets of degenerate
primers designed to amplify part of the coat protein (CP) gene of the
DNA A component. The first primer set used (AV494 and AC1048) amplify
the approximately 550bp core region of the CP gene (Wyatt & Brown,
1996). The second primer set used (VD360 and CD1266) amplify an
approximately 800bp fragment representing more than 90% of the CP gene
(Delatte et al., 2005). PCR products of the expected size were
obtained with both sets of primers. No PCR products were obtained with
degenerate primers designed for begomovirus DNA B or DNA β. PCR
products obtained with primers VD360 and CD1266 from one sample each
originating from Foumboudzivouni (EMBL accession no. AM156758),
Foumbouni (AM156760) and Simboussa (AM156759) were cloned and sequenced.
The three sequences showed 97% nucleotide sequence identity (DNAMAN,
Lynnon BioSoft). The most significant sequence alignments (NCBI, BLASTn)
were 95 to 96% with Tobacco leaf curl Zimbabwe virus (TbLCZV;
AF350330) and 83 to 85% with Chayotte yellow mosaic virus (ChaYMV; AJ223191). The 552bp core CP sequences, which are sometimes
used to provide provisional identification of begomoviruses (Brown et
al., 2001), showed 95 to 97% nucleotide sequence identity with
TbLCZV and 83 to 84% with ChaYMV (Fig. 2).
These results demonstrate the
presence of TbLCZV on tobacco in the Grande-Comore Island of the Comoros
Archipelago. Previous reports have identified the presence of distinct
indigenous begomoviruses on tomato in the south west islands of the
Indian Ocean (Delatte et al., 2005), but this is the first report
of TbLCZV.
++Figure 1: Severe symptoms of leaf curling and yellowing observed on tobacco plants in the field on the Grande Comore Island of the Comoros Archipelago
Figure 1: Severe symptoms of leaf curling and yellowing observed on tobacco plants in the field on the Grande Comore Island of the Comoros Archipelago
+Figure 2: Neighbour joining tree indicating the relationships between the 522 bp core region of the coat protein of three isolates of Tobacco leaf curl Zimbabwe virus (TbLCZV) from the Grande Comore Island and those of representative African and Mediterranean begomovirus sequences. The sequence alignment and the tree construction were conducted using DNAMAN software (Lynnon BioSoft, Quebec, Canada). The tree was rooted on Tobacco leaf curl Japan virus (TbLCJV, AB028604). Numbers associated with the nodes indicate the percentage support for those nodes in 1000 bootstrap replicates. Horizontal distances represent genetic distances, as indicated by the scale bar, whereas vertical distances are arbitrary. Nucleotide sequence database accession numbers of sequences used in this study: Tomato yellow leaf curl virus - Mild[Reunion] (TYLCV-Mld[RE]; AJ865337), TYLCV-Mld (X76319), TYLCV (X15656), Tomato leaf curl Madagascar virus - [Morondava] (ToLCMGV-[Mor], AJ865338), ToLCMGV-[Toliary] (ToLCMGV-[Tol], AJ865339), Tomato leaf curl Mayotte virus - [Dembeni] (ToLCMGV-[Dem], AJ865341), ToLCMGV-[Kahani] (ToLCMGV-[Kah], AJ865340), South African cassava mosaic virus - [M12] (SACMV-[M12], AJ422132), EastAfrican cassava mosaic virus - [Tanzania] (EACMV-[TZ], Z83256), African cassava mosaic virus - Uganda Severe (ACMV-UgSvr, AF26806), Tomato curly stunt virus - South Africa (ToCSV-SA, AF261885), Cotton leaf curl Gezira virus - [Sida] (CLCuGV-[Si], AY036007), Tobacco leaf curl Zimbabwe virus - [Simboussa] (TbLCZV-[Sim], AM156759), TbLCZV - [Foumbouni] (TbLCZV-[Fon], AM156760), TbLCZV - [Foumboudzivouni] (TbLCZV-[Fod], AM156758), TbLCZV - [B] (AF077026), TbLCZV - [H] (AF077747), TbLCZV - [M] (AF077748), TbLCZV - [S] (AF077749) and Chayotte yellow mosaic virus (ChaYMV, AJ223191).
Figure 2: Neighbour joining tree indicating the relationships between the 522 bp core region of the coat protein of three isolates of Tobacco leaf curl Zimbabwe virus (TbLCZV) from the Grande Comore Island and those of representative African and Mediterranean begomovirus sequences. The sequence alignment and the tree construction were conducted using DNAMAN software (Lynnon BioSoft, Quebec, Canada). The tree was rooted on Tobacco leaf curl Japan virus (TbLCJV, AB028604). Numbers associated with the nodes indicate the percentage support for those nodes in 1000 bootstrap replicates. Horizontal distances represent genetic distances, as indicated by the scale bar, whereas vertical distances are arbitrary. Nucleotide sequence database accession numbers of sequences used in this study: Tomato yellow leaf curl virus - Mild[Reunion] (TYLCV-Mld[RE]; AJ865337), TYLCV-Mld (X76319), TYLCV (X15656), Tomato leaf curl Madagascar virus - [Morondava] (ToLCMGV-[Mor], AJ865338), ToLCMGV-[Toliary] (ToLCMGV-[Tol], AJ865339), Tomato leaf curl Mayotte virus - [Dembeni] (ToLCMGV-[Dem], AJ865341), ToLCMGV-[Kahani] (ToLCMGV-[Kah], AJ865340), South African cassava mosaic virus - [M12] (SACMV-[M12], AJ422132), EastAfrican cassava mosaic virus - [Tanzania] (EACMV-[TZ], Z83256), African cassava mosaic virus - Uganda Severe (ACMV-UgSvr, AF26806), Tomato curly stunt virus - South Africa (ToCSV-SA, AF261885), Cotton leaf curl Gezira virus - [Sida] (CLCuGV-[Si], AY036007), Tobacco leaf curl Zimbabwe virus - [Simboussa] (TbLCZV-[Sim], AM156759), TbLCZV - [Foumbouni] (TbLCZV-[Fon], AM156760), TbLCZV - [Foumboudzivouni] (TbLCZV-[Fod], AM156758), TbLCZV - [B] (AF077026), TbLCZV - [H] (AF077747), TbLCZV - [M] (AF077748), TbLCZV - [S] (AF077749) and Chayotte yellow mosaic virus (ChaYMV, AJ223191).
Brown JK, Idris AM, Torres-Jerez I, Banks GK, Wyatt SD, 2001. The
core region of the coat protein gene is highly useful for establishing
the provisional identification and classification of begomoviruses. Archives
of Virology146, 1581-1598.
Delatte H, Martin DP, Naze F, Goldbach R, 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 Virology86, 1533-1542.
Wyatt SD, Brown JK, 1996. Detection of subgroup III geminivirus
isolates in leaf extracts by degenerate primers and polymerase chain
reaction. Phytopathology86, 1288-1293.
This report was formally published in Plant Pathology