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Vector Relations

Infectivity Neutralization of Rice Tungro-Associated Viruses Acquired by Vector Leafhoppers. Hiroyuki Hibino, International Rice Research Institute, P.O. Box 933, Manila, Philippines; Pepito Q. Cabauatan, International Rice Research Institute, P.O. Box 933, Manila, Philippines. Phytopathology 77:473-476. Accepted for publication 22 September 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/Phyto-77-473.

Rice tungro bacilliform virus (RTBV) depends on rice tungro spherical virus (RTSV) for its transmission by the vector leafhopper Nephotettix virescens. Adult leafhoppers transmit RTBV and RTSV in a semipersistent manner. Leafhoppers that had access to plants infected with both RTBV and RTSV were fed through membranes on anti-RTSV or -RTBV immunoglobulin (IgG). When the leafhoppers fed for 16 hr on anti-RTBV IgG diluted 25 times, RTBV infectivity was neutralized and mostly RTSV was transmitted. When the leafhoppers fed for 16 hr on anti-RTSV IgG diluted 25 times, RTSV transmission was markedly reduced and mostly RTBV was transmitted. In two of six trials, however, RTSV infectivity was completely neutralized by the anti-RTSV IgG treatment. When the leafhoppers that had access to RTSV-infected plants were fed on anti-RTSV IgG, they lost most of their ability to transmit RTSV but retained the ability to acquire and transmit RTBV. When the leafhoppers that had access to plants infected with both viruses were fed on a mixture of the anti-viral IgGs and then transferred to plants infected with both viruses for reacquisition access, they reacquired both viruses. These results indicate that RTSV virions may not bear the helper function for RTBV transmission by leafhoppers.