ARS | Publication request: Comparison of ELISA and RT-PCR assays for the detection of Tomato spotted wilt virus in peanut

Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 16, 2009
Publication Date: July 2, 2009
Citation: Dang, P.M., Rowland, D., Faircloth, W.H. 2009. Comparison of ELISA and RT-PCR assays for the detection of Tomato spotted wilt virus in peanut. Peanut Sci. 36:133-137.

Interpretive Summary: Plants grown in the field can be naturally infected with viruses which can reduce plant health and result in yield loss. In the southeastern United States, Tomato spotted wilt virus (TSWV) is a major problem in peanut with estimated losses exceeding $40 million. Infected peanut plants show a wide range of visual symptoms including concentric ring spots, leaf chlorosis, stunting, deformity and discoloration of pods and kernels, even death of severely infected plants. Two independent detection methods for the presence of the virus in peanut plants have been used: one method utilizes antibody recognition of viral proteins and the other involves the detection of viral codes in plants. A direct comparison of the two techniques in evaluating infection rates of field grown peanut plants would help to determine if the results are comparable. Peanut roots from field grown plants were collected and subjected to both tests. No significant statistical difference between testing results for TSWV infection using these two methods were observed. This information suggests that both methods are comparable for detecting TSWV infection rates in field grown peanuts.

Technical Abstract: Peanut (Arachis hypogaea L.) plants infected with Tomato spotted wilt virus (TSWV) can display a wide range of disease incidence and severity depending on the year and location. Diagnosis of TSWV infection can be accomplished using enzyme-linked immunosorbent assay (ELISA) or reverse transcription polymerase chain reaction (RT-PCR) but there has been no report of a direct comparison of the success of the two techniques in evaluating infection rates of field grown peanut plants. We collected peanut roots from field grown plants, 76 in 2006 and 48 for 2007, and subjected these samples to both ELISA and RT-PCR to test for the presence of TSWV. Out of 124 samples, 50 (40%) vs. 57 (46%) of the samples were positive for TSWV infection by ELISA and RT-PCR respectively. In 13.7% of these samples, ELISA and RT-PCR differed in their testing results. However, statistical analysis showed no significant difference between testing results for TSWV infection between these two methods. This result supports the conclusion that ELISA and RT-PCR are comparable methods for detecting TSWV infection rates in field grown peanuts.