ABSTRACT
The conditions of soil and climate in the northeast of Brazil are favorable to cultivation of melon (Cucumis melo). However, there are various sanitary problems that affect productivity, especially diseases caused by viruses. This research had the objective of carrying out the biological and serological characterisation of an isolate of the Squash mosaic virus (SqMV), obtained in the State of Ceará, Brazil. In studies into host range, the virus infected systemically only five species of Cucurbitaceae family, and caused local lesions in Chenopodium amaranticolor and C. quinoa. Mixed-infection studies of SqMV with a virus specie from the genus Potyvirus demonstrated a synergistic effect between the viruses. Chemical purification of SqMV was possible using melon plants, and immunisation of rabbits with the purified preparation enabled the production of a specific polyclonal antiserum. The antiserum produced presented titers of 1:10,000 when evaluated by plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA), 1:160,000 by immunoprecipitation ELISA (IP-PTA-ELISA) and 1:1,024 by agar double diffusion. Studies by agar double diffusion of the serological relationship between SqMV and the Cowpea severe mosaic virus (CPSMV), of the genus Comovirus, demonstrated a unilateral relationship against their homologous and heterologous antisera.
Key words:
Comovirus; Mixed infection; IP-PTA-ELISA; Serological relationship
