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Research article - Peer-reviewed, 2013

Molecular characterization of begomoviruses and DNA satellites associated with okra leaf curl disease in Cameroon

Leke, Walter Nkeabeng; Sattar, Muhammad Naeem; Ngane, E B; Ngeve, JM; Kvarnheden, Anders; Brown, Judith K

Abstract

Okra leaf curl disease (OLCD) is the most important viral disease of okra in West Africa. In this study, a complex of begomoviruses and associated DNA satellites were identified in symptomatic okra plants from southwestern Cameroon. Sequence analyses showed that two of the plants (Lik1 and Njo5) were infected with a begomovirus being a recombinant of cotton leaf curl Gezira virus (CLCuGeV) and okra yellow crinkle virus (OYCrV). The recombinant genome shared highest nucleotide identity with isolates of CLCuGeV at 87.8% and is therefore considered to be member of a new begomovirus species, Okra leaf curl Cameroon virus (OLCuCMV). One plant (Mue5) was infected by a begomovirus with 95.8% nucleotide identy to CLCuGeV, while in the plants Lik1, Muel and Njo5, a begomovirus was identified showing highest nucleotide identity at 93.7% with OYCrV. The nucleotide comparisons and phylogenetic analyses suggest that these isolates represent new Cameroonian strains of CLCuGeV and OYCrV (CLCuGeV-CM and OYCrV-CM). Mixed infection of OLCuCMV and OYCrV-CM was found in two of the plants. A betasatellite and two divergent alphasatellites were also associated with the begomoviruses. The betasatellite was identified as cotton leaf curl Gezira betasatellite (CLCuGeB) with the highest nucleotide identity at 93.3% to othei African isolates of CLCuGeB. The alphasatellites, herein named Alpha-1 and Alpha-2, shared 973% and 95.2% identity, respectively, with cotton leaf curl Gezira alphasatellite (CLCuGeA) and okra leaf curl Burkina Faso alphasatellite (OLCuBFA). These collective results emphasize the extent of diversity among okra-infecting begomovirus-satellite complexes in western Africa. (C) 2013 Elsevier B.V. All rights reserved.

Keywords

Abelmoschus esculentus; Alphasatellite; Begomovirus ecology; Betasatellite; Geminivirus

Published in

Virus Research
2013, Volume: 174, number: 1-2, pages: 116-125
Publisher: ELSEVIER SCIENCE BV