Invasive Species Compendium

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Abstract

Leonotis nepetaefolia: an important plant virus reservoir in Central Mexico.

Abstract

The presence of viruses in the weed Leonotis nepetaefolia in central México is reported from two field surveys. L. nepetaefolia, with viral-like symptoms such as mosaic, leaf deformation and calico, was observed growing next to cultivated fields in the Valley of Atlixco, Puebla, an important agricultural region in Mexico. The viruses harbored by this plant were characterized biologically, serologically and by molecular methods. The viruses detected were Alfalfa mosaic virus (AMV), Cucumber mosaic virus (CMV), a satellite RNA of CMV (CMV satRNA) and Tobacco mosaic virus (TMV). This last one was detected only during the first survey. CMV was the predominant virus found in both surveys, and was associated mostly to mosaic symptom. Phylogenetic analysis based on the coat protein gene sequence of CMV indicated that this isolate belongs to subgroup IA and confirmed that it is a mosaic-inducing isolate, whereas AMV belongs to subgroup II. Finally, CMV satRNA was found to be a non-necrogenic ameliorative variant, both by symptomatology and by phylogenetic analysis. Our results suggest that L. nepetaefolia is a reservoir for several viruses in central Mexico, and given its wide distribution in several parts of the world, its role as a virus reservoir could be more general.