Application of the Enzyme-Linked Immunosorbent Assay for Detecting Viruses in Soybean Seed and Plants.

Abstract

The enzyme-linked immunosorbent assay (ELISA) test procedure easily detected tobacco ringspot virus (TRSV) or soybean mosaic virus (SMV) in individual soybean [Glycine max] seed, to 1/2500 and 1/160 (wt/vol) dilutions, respectively, of seed extracts made in phosphate-buffered saline containing polyvinyl pyrrolidone (MW 40,000). Sensitivity for detection of the viruses in leaf extracts relative to seed extracts was similar for TRSV and about 4 times greater for SMV. Both viruses also would be detectable in extracts from seed batches containing low proportions of infected seed: less than 1% for TRSV and about 2-4% for SMV. Germination significantly improved the sensitivity of such tests with SMV. The ELISA tests may be widely applicable in testing seed for viruses, especially with large-seeded species such as legumes and cereals. Testing seedlings instead of seed could further broaden applicability to other systems.