A crucial step in managing vineyard health is ensuring that all new propagation and planting material is free of deleterious viral pathogens. Sourcing virus-free planting material, however, is not always possible for certain grapevine varieties or clones. Affinity Labs offers a virus elimination service, which uses a combination of tissue culture, chemotherapy and thermotherapy to eliminate deleterious viruses from plant material.
The virus elimination process
There are multiple steps involved in the virus elimination process including several tissue culture steps, chemotherapy and thermotherapy treatment, PCR confirmation of virus elimination at multiple checkpoints and hardening-off of plantlets from tissue culture in the glasshouse. Due to the unpredictable nature of tissue culture, and the variation across different clones in response time to treatment, it is difficult to predict exactly how long the process will take. As an estimate, the time from receiving tissue for virus elimination to delivery of virus-free plantlets takes approximately 12-24 months. The plantlets then need to be grown in pots (within the client’s own facilities) for two dormancy periods before a final test is carried out to confirm the vine’s ‘virus-free’ status. It is only after this final test that their release into the field would be recommended.
Plants subjected to the virus elimination service will be provided ‘virus-free,’ with the possible exception of Grapevine rupestris stem pitting-associated virus (GRSPaV). GRSPaV is found in approximately 95% of all grapevines in Australia, is usually asymptomatic and is sometimes impossible to eliminate from vines. The ‘virus-free’ status is determined by a PCR-based screening method and is limited to the viruses within the Affinity Labs complete virus screen. Other unknown viruses may also be removed during treatment, but this is not guaranteed. In some instances, a virus titre may be present at very low levels that is below the detection threshold of PCR detection. Screening is therefore required at multiple points through the elimination process and after two dormancies before the vines can be confidently given a ‘virus-free’ status. Affinity Labs does not guarantee that the plants are ‘virus-free’ until this final testing is done.
Potted plants are preferred. Each pot should contain at least two actively growing vines which originated from the same vine. Woody canes or dormant rootlings are also accepted (approximately 30 cm in length), but please note that an extra two months are needed to grow these in the glasshouse prior to the virus elimination process.
Interstate samples and quarantine regulations
To submit samples from outside South Australia, the vines must be located within a Phylloxera Exclusion Zone (PEZ). Current maps of phylloxera management zones in Australia are available from the Vinehealth Australia website. Affinity Labs cannot receive material for virus elimination from phylloxera risk and infested zones (PRZ and PIZ).
Ten growing shoots (15 cm each) from a single actively growing vine are required, dipped in saturated floral foam. Samples should be accompanied by a plant virus elimination services agreement and a signed plant material movement declaration form (virus testing) and must be packaged in accordance with CA12 requirements (see form for details). Samples should be sent by overnight express post at the beginning of the week, to ensure no delays in transit, and when the temperature is below 30°C.
Request this service by completing the enquiry form.
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Affinity Labs’ NATA-accredited laboratories perform more than 100,000 analyses per year and have serviced the Australian wine industry since 1984. The laboratories deliver high-quality cost-effective routine, export or specialist analyses, whether it is for a single sample or a large batch of samples