Separation of Citrus Tristeza Virus (CTV) Serotypes Through Aphid Transmission

Abstract

Twenty different subcultures of citrus tristeza virus (CTV) were obtained from 15 different original field sources by transmission with the aphid Toxoptera citricidus (Kirk). The 20 aphid-transmitted subcultures (ATS), and 15 field sources were tested by double sandwich indiret ELISA using two monoclonal antibodies (MAb), MCA13 and 3DF1, and by double sandwich ELISA using polyclonal antibodies (PAb). Four ATS isolates derived from two field source (FS) isolates showed reactions different from their parent FS. For example, a mild CTV from one FS, M27, reacted strongly to MCA13, 3DF1 and PAb, while three ATS isolates from M27 reacted with PAb, but not with either MAb. These results indicate that at least two different serotypes can infect one citrus plant, and that separation of certain serotypes can occur through aphid transmission.