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 curldisease (LCD) symptoms suggestive of begomovirus infection. In Asia, different begomovirus-satellitecomplexes have been identified in A. conyzoides. The objective of this study was to determine the identityof the suspect begomoviruses and their associated satellites in A. conyzoides in Cameroon. The resultsindicated that all three symptomatic A. conyzoides plants examined were infected with a new begomovirusspecies, herein named Ageratum leaf curl Cameroon virus (ALCCMV). The ALCCMV genomesequences shared their highest identity, at 84.3-88.5%, with a group of tomato-infecting begomovirusesfrom West Africa. In addition, a betasatellite and an alphasatellite were cloned from the same symptomaticA. conyzoides plants. The betasatellite sequences shared limited sequence identity at 37% orless with the betasatellite Cotton leaf curl Gezira betasatellite, and the new betasatellite species is hereinnamed Ageratum leaf curl Cameroon betasatellite (ALCCMB). The alphasatellite shared 80% nt identitywith Tomato leaf curl Cameroon alphasatellite (ToLCCMA), and the new alphasatellite species is hereinnamed Ageratum leaf curl Cameroon alphasatellite (ALCCMA). In addition, two fragments containingbegomovirus-alphasatellite sequences were cloned from sample AGLI4, and they were related to thedefecting interfering molecule (Y14167) associated with Ageratum yellow vein virus from Asia. Theseresults suggest that the begomoviral-satellite complexes infecting A. conyzoides in Cameroon may be ascomplex or more so, to species and strains reported thus far from Asia.