Comparison of TAS-ELISA, dot and tissue blot, ISEM and immunocapture RT-PCR assays for the detection of Yam mosaic virus in yam tissues

The performance of five techniques for detecting Yam mosaic virus (YMV), genus Potyvirus, in Dioscorea rotundata was evaluated. Triple antibody sandwich (TAS) enzyme-linked immunosorbent assay (ELISA), dot (DBI) and direct tissue blot immunoassays (DTBI), immunosorbent electron microscopy (ISEM) and immunocapture reverse transcriptase polymerase chain reaction (IC-RT-PCR) detected YMV in stems, leaf petioles, leaves and tubers. Younger leaves were more suitable for the detection of YMV using TAS-ELISA and DBI. DBI was as sensitive as TAS-ELISA when the detecting antibody was YMV-M24. The IC-RT-PCR technique was five times more sensitive than the purely protein-based serological detection methods. TAS-ELISA, DTBI and symptomatology were more suitable in detecting YMV in yam tubers than IC-RT-PCR and ISEM because of their sensitivity and reliability. The DTBI assays were very useful for the detection of YMV in yam tubers and tuber sprouts.