Determination of the temporal and spatial distribution of aster yellows phytoplasma in infected grapevine plants
Burger, J T
University of Stellenbosch. Faculty of AgriSciences. Department of Genetics
Maree, H J
Burger, J T
Highly specific PCR-based assays to detect aster yellows phytoplasma (AY) have been developed and are continuously being refined. The reliability and accuracy of these assays however, is still a concern due to the low titre and uneven spatial distribution of the pathogen in plants.
The aim with this project to determine the spatial distribution of aster yellows in grapevines at various time points during the growing season – both in vines displaying aster yellow symptoms, and vines displaying the ‘recovery phenotype’. The result from this study will assist in the development of reliable diagnostic assays since the optimal time and tissue type will be determined. By investigating the distribution of aster yellows in vines that were pruned back, and have seemingly recovered from phytoplasma infection (‘recovery phenotype’), a possible explanation for this phenomenon, as well as the longer term efficiency of this practice, can be put forward.