Comparison between Indirect ELISA and TBIA for Detection of Some Viruses in Naturally Infected Faba Bean Plants

Abstract

Aims: The main objective of the present study is to compare between indirect ELISA and TBIA for detecting some faba bean (Vicia faba L) viruses in naturally infected faba bean plants. Methodology: Fifty four samples with different mosaic and mottle symptoms were separately collected from faba bean plants of different regions of the open fields of Alexandria governorate during the growing season of 2013/2014. Stems of samples showing such symptoms were taken from each sample and indexed by indirect ELISA and TBIA for infection with Broad bean mottle virus (BBMV), Broad bean true mosaic virus (BBTMV), Broad bean stain virus (BBSV), Bean yellow mosaic virus (BYMV) and Pea seed borne mosaic virus (PSbMV). The incidence of these viruses and the single and mixed infections in samples were determined by both tests. Also, comparison between the sensitivity of indirect ELISA and TBIA for detection of faba bean viruses in samples was assessed. Results: Both indirect ELISA and TBIA revealed that BYMV was the most common spread virus followed by BBTMV, PSbMV, BBMV and BBSV. However TBIA proved to be relatively more sensitive than indirect ELISA. BYMV, BBMV, and BBSV were detected by TBIA and indirect ELISA in 77.78 and 74.07%; 33.33 and 29.63%; 31.48 and 29.63% of the tested samples, respectively. The other two viruses, BBTMV and PSbMV viruses were detected by both tests with the same frequency, 40.74 and 35.19%, respectively. Single, double, triple and other multiple infections were detected by TBIA and indirect ELISA. Conclusion: The study suggests that, not all infected samples with a particular virus (es) detected by TBIA were observed with indirect ELISA. TBIA was more sensitive, more practical and cheaper and does not require sophisticated facilities than indirect ELISA.