Complete genome sequence of a new bipartite begomovirus infecting fluted pumpkin (Telfairia occidentalis) plants in Cameroon.

The complete genome sequence was determined and characterized for a previously unreported bipartite begomovirus from fluted pumpkin (Telfairia occidentalis, family Cucurbitaceae) plants displaying mosaic symptoms in Cameroon. The DNA-A and DNA-B components were ~2.7 kb and ~2.6 kb in size, and the arrangement of viral coding regions on the genomic components was like those characteristic of other known bipartite begomoviruses originating in the Old World. While the DNA-A component was more closely related to that of chayote yellow mosaic virus (ChaYMV), at 78 %, the DNA-B component was more closely related to that of soybean chlorotic blotch virus (SbCBV), at 64 %. This newly discovered bipartite Old World virus is herein named telfairia mosaic virus (TelMV).

Complete genome sequence of a new bipartite begomovirus infecting cotton in the Republic of Benin in West Africa.

Here, we report the complete genome sequence of a novel bipartite begomovirus isolated from cotton plants (Gossypium raimondii, Malvaceae) exhibiting light yellow mosaic symptoms. The genome sequence was determined by Illumina DNA sequencing and confirmed by Sanger sequencing of RCA-enriched, cloned circular genomic components. The DNA-A and DNA-B components were each ~2.7 kb in size, and their genome arrangement was characteristic of other Old World bipartite begomoviruses. While the DNA-A component was most closely related to tobacco leaf curl Comoros virus (TbLCKMV) at 80 %, the DNA-B component had as its closet relative soybean chlorotic blotch virus (SbCBV) at 66 %. This previously undescribed begomovirus is herein named "cotton yellow mosaic virus" (CYMV).

Mixed infection by two West African tomato-infecting begomoviruses and ageratum leaf curl Cameroon betasatellite in tomato in Cameroon.

Begomovirus isolates ToF3B2 and ToF3B17 and betasatellite isolate SatBToF3 were obtained from the same infected tomato plant showing begomovirus disease symptoms in Fontem, Cameroon. The full-length nucleotide sequences of ToF3B2, ToF3B17 and SatBToF3 were cloned and sequenced and were determined to be 2,797 nt, 2,794 and 1,373 nt long respectively. When compared with other begomovirus and betasatellite sequences, ToF3B2 was 93.5 % identical to Tomato leaf curl Togo virus, ToF3B17 was 95 % identical to Tomato leaf curl Cameroon virus and SatBToF3 was 92 % identical to Ageratum leaf curl Cameroon betasatellite (ALCCMB), respectively. The identification of ALCCMB in Ageratum and now in tomato strongly suggests Ageratum may be an alternative host to these viruses and that ALCCMB is non host specific and may cause severe diseases when transmitted to other crops.

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

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.

Ageratum conyzoides: a host to a unique begomovirus disease complex in Cameroon.

Ageratum conyzoides (goat weed) is a widespread uncultivated species in Cameroon that exhibits leaf curl disease (LCD) symptoms suggestive of begomovirus infection. In Asia, different begomovirus-satellite complexes have been identified in A. conyzoides. The objective of this study was to determine the identity of the suspect begomoviruses and their associated satellites in A. conyzoides in Cameroon. The results indicated that all three symptomatic A. conyzoides plants examined were infected with a new begomovirus species, herein named Ageratum leaf curl Cameroon virus (ALCCMV). The ALCCMV genome sequences shared their highest identity, at 84.3-88.5%, with a group of tomato-infecting begomoviruses from West Africa. In addition, a betasatellite and an alphasatellite were cloned from the same symptomatic A. conyzoides plants. The betasatellite sequences shared limited sequence identity at 37% or less with the betasatellite Cotton leaf curl Gezira betasatellite, and the new betasatellite species is herein named Ageratum leaf curl Cameroon betasatellite (ALCCMB). The alphasatellite shared 80% nt identity with Tomato leaf curl Cameroon alphasatellite (ToLCCMA), and the new alphasatellite species is herein named Ageratum leaf curl Cameroon alphasatellite (ALCCMA). In addition, two fragments containing begomovirus-alphasatellite sequences were cloned from sample AGLI4, and they were related to the defecting interfering molecule (Y14167) associated with Ageratum yellow vein virus from Asia. These results suggest that the begomoviral-satellite complexes infecting A. conyzoides in Cameroon may be as complex or more so, to species and strains reported thus far from Asia.