Development and validation of diagnostic protocols for the detection of endemic and exotic pathogens of grapevines (formerly ‘Understanding virus management for vine improvement’)
Abstract
A suite of molecular based diagnostic tests have been developed and validated that will enhance the plant health status and biosecurity of the Australian grapevine industry. Specifically we have developed:
* Reliable sampling strategies for sensitive virus detection
* A high throughput nucleic acid extraction procedure using green tissue that should reduce the cost of RT-PCR for grapevine virus detection. This capability will also improve Australia's responsiveness to an exotic pathogen incursion.
* Validated molecular protocols for ten endemic viruses, 16 exotic viruses and bacterial blight (Xylophilus ampelinus).
The survey indicated that Australian grapevines appear to be free of some of the significant grapevine viruses and X. ampelinus.
Summary
Vine health impacts the viticultural industry at various levels, including the cost and quality of planting material, the sustainability and productivity of vineyards, the quality of the end product (wine, table grapes, dried fruit and ornamental grapevines) and export capabilities. Although Australian viticulture is not affected by some of the serious diseases or pathogens that occur in other countries, some important diseases, and associated pathogens, were introduced to Australian viticulture including leafroll and rugose wood diseases.
In Australia and other countries quarantine and certification programs exist to prevent the introduction and spread of pathogens into viticulture. These programs support the improved productivity and sustainability of the viticulture industry by the provision of high health planting material in which disease-associated pathogens such as viruses and bacteria have not been detected.
Recent literature suggests that there are approximately 60 viruses that can infect grapevine. Many of these are associated with serious diseases of grapevine and are controlled through quarantine and certification programs. There are also 15 significant bacteria, including 10 phytoplasmas, Xylophilus ampelinus, Xylella fastidiosa, Agrobacterium sp (A. rubi and A.vitis) and Xanthomonas campestris pv viticola, that can infect grapevines and which are controlled through quarantine and certification programs.
Of the 60 viruses that infect grapevines worldwide 10 viruses are endemic in Australia and these include Grapevine virus A (GVA), Grapevine virus B (GVB), Rupestris stem pitting associated virus (RSPaV), Grapevine fleck virus (GFKV), Grapevine leafroll associated viruses (GLRaV)-1, GLRaV-2, GLRaV-3, GLRaV-4, GLRaV-5 and GLRaV-9. Grapevine viruses of quarantineable significance to Australia include: GVB (strains associated with corky bark), Grapevine virus D (GVD), Secoviridae species (16 in total) and two tombusviruses (Grapevine Algerian latent virus and Petunia asteroid mosaic virus). Bacteria of quarantine significance to Australia include, Xylella fastidiosa, Xylophilus ampelinus and Flavescence dorée and Bois noir phytoplasmas.