GenUS GP 19-01
Department of Genetics, Stellenbosch University
Objectives and Rationale
Certification schemes rely on large-scale virus detection. Methods must be DALRDD approved prior to implementation. Here, four grapevine fleck virus ELISA kits were evaluated, along with optimal plant tissue, sample timing, extraction method and pooling potential. The virus genetic variability locally was determined, and detection of variants confirmed.
GFkV was identified by PCR. The specificity and sensitivity of four GFkV ELISAs determined. Optimal time and tissue for sampling was assessed. NGS analysis revealed GFkV variability. Determination of GFkV in selected mother blocks under inoculum pressure from grapevine leafroll associated virus 3 was conducted.
Little differences in sensitivity and specificity were observed amongst three ELISA kits. GFkV can be detected throughout the growing season, with the highest absorbance values obtained from March to June from phloem-rich tissue. NGS analysis revealed significant variability in 80 GFkV sources, all could be detected by ELISA.
Key Conclusion and Discussion
An entire protocol for the detection of GFkV by ELISA in the Vine improvement association certification scheme has been prepared, including ELISA kits to use, time of year and tissue to sample, the extraction method and the level of pooling. A selected kit was shown to detect all local variants.
Take Home message for Industry
A protocol for the detection of GFkV by ELISA in the Vine improvement association certification scheme has been prepared.