Wine Industry Newsletter

Grapevine red blotch virus, a WA perspective

At the Department of Primary Industries and Regional Development's (DPIRD) Manjimup Horticulture Research Facility (MHRF) resides the state's grapevine Germplasm collection, consisting of over 140 varieties and 191 clones of wine, table, multipurpose, drying and rootstock material. The collection is managed by DPIRD and utilised by the WA Vine Improvement Association (WAVIA) to supply propagation material to industry. This partnership has been in place since WAVIA’s inception in 1993.

Other grapevines planted at the MHRF include an emerging variety trial block consisting of 18 emerging varieties which were assessed for their potential under WA growing conditions by DPIRD researchers for over a decade. This work has been completed, findings published and now serves as a source block for WAVIA. The other block of grapevines at this facility is a small planting of Chardonnay vines that is reserved for pathology research activities.

The Germplasm collection is one of very few collections in Australia that conducts regular grapevine virus testing through DPIRD’s Diagnostic and Laboratory Service (DDLS). Annually, a systematic sampling regime is conducted on one third of the vines independent of variety/clone within the block. Limited by resources to test all known viruses, it was concluded with industry engagement, that testing specifically for Grapevine leafroll associated virus (GLRaV) -1 and -3 as the two most potentially damaging viruses be prioritised. The consequence of this approach means that all vines in the collection are tested for these two viruses within a three-year period.

Wine Australia is working towards a National Grapevine Collection which includes an assessment of current grapevine germplasm collections across Australia. Part of this work is to identify existing collections to be developed into nationally significant nuclear collections. DPIRD’s Germplasm collection at the MHRF was identified as a potential candidate, based on its current health status and good management practices.

Funding was provided by Wine Australia to broaden the 2022 virus testing to include 13 viruses as listed below.

  • Grapevine leaf roll virus 1
  • Grapevine leaf roll virus 2
  • Grapevine leaf roll virus 3
  • Grapevine leaf roll virus 4
  • Grapevine leaf roll virus 4 strain 5
  • Grapevine leaf roll virus 4 strain 9
  • Grapevine virus A
  • Grapevine virus B
  • Grapevine Pinot Gris virus
  • Grapevine rupestris stem pitting virus
  • Grapevine rupestris vein feathering virus
  • Grapevine fleck virus
  • Grapevine red blotch Virus

The expanded testing this year led to a surprising outcome, with the detection of Grapevine red blotch virus (GRBV) for the first time in Australia at MHRF. Prior to the detection, there had been no indication GRBV was present in the collection, as visual symptoms were not observed.  In response to the detection, DPIRD tested all grapevines at MHRF and two blocks of grapevines situated at the WA College of Agriculture – Harvey (Wokalup), due to linkages with MHRF Germplasm collection. Over 2100 vines have now been tested with 39 vines positive for GRBV, consisting of 10 different varieties (Table 1).

On 28 June 2022, the WA Chief Plant Biosecurity Officer (CPBO) at DPIRD notified the Australian Chief Plant Protection Officer (ACPPO) of the detection.  On 30 June 2022, the CPBO notified key state industry representatives, from Agriculture Producer Commission’s (APC) Wine Producer’s Committee, APC Table Grape Producer’s Committee Chair and Chair of the WAVIA, of the detection and the requirement to not remove grapevine material from MHRF. WA industry representatives were briefed on the positive detection of GBRV at the MHRF on 14 July 2022.

A Pest Control Notice was issued on both DPIRD’s MHRF and the WA College of Agriculture - Harvey to prevent any movement of grapevine material from the sites while testing was carried out and to allow for DPIRD’s researchers to conduct trace back and trace forward of the material detected with the virus.

Thankfully the varieties and clones that have tested positive are not in high demand and only small volumes of material had been distributed. Those growers who have received material have been notified.

Since the initial detection of GRBV in WA, GRBV has also been detected in Victoria and South Australia. On 14 September 2022,  Australia Grape and Wine (AGW) released information noting that it is likely GRBV was introduced into Australia through infected grapevine material prior to 1985. Given the detections in multiple states, the Consultative Committee of Emergency Plant Pests (CCEPP) is determining if further action is required. AGW and the Australian Table Grape Association are the national industry representatives on the CCEPP. 

Table 1 Positive GRBV detections at MHRF and WA College of Agriculture Harvey (Wokalup) after recent testing by DDLS

Site

Variety (clone)

Manjimup Germplasm collection

Perle de Csaba (L6V13)

Manjimup Germplasm collection

Brachetto (H102)

Manjimup Germplasm collection

Harslevelu (LN-B)

Manjimup Germplasm collection

Malbec (Kalimna1)

Manjimup Germplasm collection

Pinot Noir (D2V5)

Manjimup Germplasm collection

Kadarka (F13V3)

Manjimup Variety Trial block

Savagnin Blanc (Galicia1989)

Manjimup Pathology block

Chardonnay (unknown)

Wokalup Variety Trial block

Savagnin Blanc (Galicia1989)

Wokalup Variety Trial block

Harslevelu (LN-B)

Wokalup Variety Trial block

Brachetto (H102)

Wokalup Variety Trial block

Kadarka (F13V3)

Wokalup multiplication block

Merlot (D3V5 HT81)

Wokalup multiplication block

Chardonnay (G9V7 HT90.1)

Further information on GRBV is available on the AWRI Factsheet which covers disease symptoms, transmission, management and diagnostics.  

WA wine producers are advised to be familiar with this newly detected virus, but not to be alarmed. It is believed this virus has been present for 37 years and only 39 vines have been detected in that time. Further information surrounding GRBV in Australia will be forthcoming as information on further testing in other states and the decision by the CCEPP is made. If growers wish to have testing conducted, samples can be submitted through DDLS, but it is best to contact prior to determine the best method for sampling.  

Key DPIRD contacts available to provide support are noted below:

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