Nicotiana glauca L. is a reservoir weed of plant viruses

摘要

A great number of factors are involved in the beginning and further development of plant viral epiphytotics, thus the study of each one is of great complexity. An important factor in the ecology of any disease is the presence of hosts which in many instances are weeds present within the crop or in adyacent areas and that may harbor pathogens or their vectors. Nicotiana glauca is a perennial solanaceae plant of wide distribution in Mexico in which it is common to observe viral symptoms. Given the importance of this host as possible reservoir of important viruses of cultivated plants, our study focused to determine the etiology of the symptoms observed in the field. N. glauca samples with viral symptoms were collected from strategic points of the central part of Mexico. The following viruses were detected: Cucumber mosaic virus (CMV), Tobacco mosaic virus (TMV) and Potato virus Y (PVY); the presence of viral mixtures was not a common phenomenon. Sixteen isolations of TMV were obtained, nine of CMV and three of PVY No geminiviruses or viroids were detected.