title: Molecular characterization of begomoviruses and DNA satellites associated with okra leaf curl disease in Cameroon.
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, Mue1 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 other African isolates of CLCuGeB. The alphasatellites, herein named Alpha-1 and Alpha-2, shared 97.3% 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.
authors.affiliation: Institute of Agricultural Research for Development (IRAD), Bambui, P.O. Box 80, Bamenda, Cameroon.
authors.forename: Walter N
authors.initials: WN
authors.lastname: Leke
authors.forename: Muhammad N
authors.initials: MN
authors.lastname: Sattar
authors.forename: Emilia B
authors.initials: EB
authors.lastname: Ngane
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Ngeve
authors.forename: Anders
authors.initials: A
authors.lastname: Kvarnheden
authors.forename: Judith K
authors.initials: JK
authors.lastname: Brown
mesh_terms: D028483:Abelmoschus / Q000821:virology*; D053839:Begomovirus / Q000235:genetics* / Q000302:isolation & purification*; D002163:Cameroon; D016000:Cluster Analysis; D004276:DNA, Satellite / Q000235:genetics* / Q000302:isolation & purification*; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology*; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D004276:DNA, Satellite; D004279:DNA, Viral