Detection of Rice Viruses in Plants and Individual Insect Vectors by Latex Flocculation Test

Abstract

The latex flocculation test (LF) was employed to detect virus antigens in infected rice plants and viruliferous insects. Reciprocal of dilution end points for infected plants tested 40 days after inoculation were 160, 40, 5120, 5120, 10,240, 40 and 80 for rice gall dwarf (RGDV), rice ragged stunt (RRSV), rice dwarf (RDV), rice grassy stunt (RGSV), rice stripe (RSV), rice tungro bacilliform (RTBV), and rice tungro spherical (RTSV) viruses, respectively. Virus antigens were detected in the following individual insects: Nephotettix nigropictus viruliferous for RGDV or RDV. Nilaparvata lugens viruliferous for RGSV, and Laodelphax striatellus viruliferous for RSV. The inability to detect RRSV in viruliferous N. lugens was caused by interference by an insect-host component. Sensitivity of LF for detecting RGDV was compared with the agar gel diffusion test and enzyme-linked immunosorbent assay.