Geminiviruses Infecting Tomato Crops in Nicaragua.

Geminiviruses transmitted by whiteflies are believed to be responsible for the devastating epidemic in tomato crops in Nicaragua, as well as in other Central American countries. Polymerase chain reaction with degenerate primers was used to amplify partial sequences of the geminivirus coat protein gene from samples of diseased tomato plants collected from the major tomato-growing areas of Nicaragua. The data indicated the presence of geminiviruses in all tested regions of the country. DNA sequence analysis and phylogenetic analysis of the amplified sequences showed that they corresponded to four different geminiviruses related to the other begomoviruses native to the Americas. One of the viruses, which was detected in three regions of Nicaragua, is probably Sinaloa tomato leaf curl virus. The sequences of two of the other detected viruses showed close relationships with several geminiviruses, including Tomato mottle virus, Tomato leaf crumple virus, and Sida golden mosaic virus, all of which previously have been reported from Central America. The fourth virus is closely related at sequence level to a tomato-infecting geminivirus from Honduras, putatively designated Tomato mild mottle virus. This virus seems to be different from the other known American begomoviruses because it groups separately in the phylogenetic analysis.