IDENTIFICATION, PARTIAL CHARACTERIZATION, AND DISTRIBUTION OF VIRUSES INFECTING ALLIUM CROPS IN SOUTH AND SOUTHEAST ASIA
In attempts to improve the characterization of viruses infecting Allium species, several pure isolates of poty- and carlaviruses and filamentous miteborne viruses were obtained and antisera (AS) and monoclonal antibodies (MAB) specific to these isolates were produced. Using a panel of six AS and five MAB prepared in Braunschweig and five AS produced by other researchers to viruses infecting Allium species, the whole range of hitherto known allium viruses with elongated particles was detected, chiefly by ELISA but also by immunoelectron microscopy (IEM). These antibodies were used for analyzing about 200 samples from European and other countries as well as approximately 500 allium samples collected during virus surveys in South and Southeast Asia. Results showed that virus incidence was highest in vegetatively propagated garlic and shallot cultivars. The number of viruses detected in individual samples varied considerably with Allium species and geographical origin. The range of antibodies used permitted a clear serological differentiation among poty- and carlaviruses and among miteborne filamentous viruses which have erroneously been assigned recently to the genus rymovirus of the Potyviridae. In total at least six potyviruses, two carlaviruses of which shallot-latent virus comprises at least four serologically distinct types, and five types of miteborne filamentous viruses appeared to be present in the allium samples studied. Additionally, isometric particles resembling cryptic viruses were often detected in onion, Welsh onion, and leek. In one instance, Welsh onion was shown to be infected with tobacco necrosis virus. By determining particle morphology, cytology, and coat protein size, garlic common latent and shallot latent carlaviruses and some of the miteborne filamentous viruses were partially characterized.
Barg, E., Lesemann, D.-E., Vetten, H.J. and Green, S.K. (1994). IDENTIFICATION, PARTIAL CHARACTERIZATION, AND DISTRIBUTION OF VIRUSES INFECTING ALLIUM CROPS IN SOUTH AND SOUTHEAST ASIA. Acta Hortic. 358, 251-258