BIOLOGICAL, PHYSICAL-CHEMICAL AND IMMUNOLOGICAL PROPERTIES EXHIBITED BY THE LETTUCE MOTTLE VIRUS, A POSSIBLE SEQUIVIRIDAE

ABSTRACT

Plants of lettuce (Lactuca sativa) cv ‘Verônica’ showing mottle symptoms were submitted to biological, serological and physicochemical tests and to electron microscopy observations to determine a possible association of a virus to that symptomatology. All the purification methods yielded virus isolates in low concentration, as observed by the low number of isometric particles in electron microscopy exam and in accordance to local lesion assay on Chenopodium quinoa. The host range was restricted to a few species of Asteraceae, Chenopodiaceae and Solanaceae, and most commercial lettuce cultivars developed mottle when mechanically inoculated with the virus. Helichrysum bracteatum, a spontaneous Asteraceae, was found to be as a potencial differential host since it is susceptible to this virus and not to Lettuce mosaic virus (Potyvirus). A serological relationship with the Dandelion yellow mosaic virus (Sequivirus) was demonstrated by PTA-ELISA.

KEY WORDS:
Differential host; Lactuca sativa; Lettuce mottle virus (LeMoV); Sequivirus.