Comparison of Bioassay and Enzyme-Linked Immunosorbent Assay for Quantification of 'Spodoptera frugiperda' Nuclear Polyhedrosis Virus in Soil

摘要

Standard curves with known amounts of Spodoptera frugiperda nuclear polyhedrosis virus (NPV) in soil were established with a bioassay and with an enzyme-linked immunosorbent assay (ELISA). The bioassay detected as few as 4 x 10 to the 4th power polyhedral inclusion bodies (PIB)/g of sandy soil and < 10 PIB/g of soils with large amounts of silt or clay. The ELISA detected as few as 360 PIB/g in all three soil types, and absorbance values were inversely related to the amount of clay. Results of the bioassay and ELISA were significantly (P < 0.01) correlated for natural NPV from field samples of silt (R equal 0.961) and sandy soil (R=0.723). Soil samples from Louisiana pastures and corn fields contain up to 7.6 times 10 to the 4th power PIB/g, and 2 times 10 to the 4th power PIB/g are commonly present.