What if disease were to hit our vineyards and we lost New Zealand’s unique grape varieties?
Dr Jean Carlos Bettoni has a plan to make sure these, and other grape species from around the world, are protected.
The solution is cryopreservation. Jean started as a Postdoctoral Research Fellow at Lincoln University late last year working with Dr Olaf Schelezki and Associate Professor Amber Parker. He has extensive experience working in plant tissue culture and cryopreservation, having contributed to the creation of the world’s first grape species cryobank for the United States Department of Agriculture (USDA) at the National Laboratory for Genetic Resources Preservation in Fort Collins, Colorado back in 2019-2020.
He’s brought his expertise to New Zealand with the long-term goal of developing a cryopreservation facility at Lincoln. In the meantime, he is already applying tissue culture techniques and working on eradicating diseases using cryotherapy-based techniques.
Using careful science and liquid nitrogen, Jean and other cryopreservation scientists around the world could be key to saving species from extinction.
Why is this a concern?
Diseases can spread quickly across monocultured plants. It’s why the bananas we eat today are different from what was sold in stores in the early 1900s. Panama Disease, caused by a fungal infection, spread throughout Gros Michel banana plants in the 1950s. They became functionally extinct on a commercial level and had to be replaced with the modern Cavendish variety.
It’s the same with grapes and all other monocultures. The way many commercial growers operate puts singular species at greater risk of extinction.
Disease is not the only risk. An increase in extreme weather events is forecast due to climate change. With enough fluctuation, our plant species could seriously suffer.
Lincoln University has some unique grape varieties from around the world, which provide a rich genetic repository.
“We have a big mixture of different varieties” Jean says. “We have few plants of some varieties, and we don’t want to lose that biodiversity.
“The main goal of cryopreservation is to have a safe collection, in case anything happens.”
What are cryotherapy and cryopreservation?
Both of these techniques are achieved by carefully processing a tiny piece of grapevine, propagating it in a sterile environment called a tissue culture, and extracting just a single millimetre of material. It’s then dehydrated, locked in an airtight container and immersed in liquid nitrogen.
Provided the liquid is routinely topped up, the sample plant material can stay there indefinitely. Retaining samples like this is called cryopreservation.
When it’s time for them to come out, the tiny shoots can be propagated in the lab with a relatively high success rate. By preserving hundreds of shoots at a time, it’s almost guaranteed the species will be restorable.
The added bonus of this is cryotherapy, which works by exploiting which cells the viruses infect. It’s an exciting new option in the horticulture toolbox.
When the shoots are immersed in the liquid nitrogen, the freezing temperatures destroy all of the outer cells. Most grapevine viruses reside in this outer plant tissue and don’t infect the meristem cells, which exist at the growing tips of the plant.
That means Jean and other cryopreservation scientists can take shoots from a diseased grapevine, process it and freeze it, then create a perfectly healthy, virus-free clone.
“We’re 100% confident that we are able to remove the virus.
“It’s a very efficient tool at destroying anything that might be compromised, and, in the case of grapes, we can do it at the same time as cryopreservation.”
This methodology extends far beyond the vineyard. “We have successfully applied cryotherapy-based techniques to eradicate viruses and viroids in diverse crops, including apple, kiwifruit, potato, and quince.”
Where to next?
Creating a dedicated cryopreservation facility at Lincoln is a long-term goal, but Jean is confident it can happen.
“A more immediate and feasible aim is to establish a secure backup in tissue culture and then use cryopreservation as a tool to eradicate viruses.
“This does not require a full cryo-facility; we just need access to a basic tissue culture lab and a source of liquid nitrogen.”
There are labs all over the world working with and researching cryopreservation, but it isn’t enough to cover all of our biodiversity.
That is why Jean and 18 other cryopreservation researchers around the globe served as cryopreservation consultants for the Food and Agriculture Organization of the United Nations (FAO) to develop the Practical Guide for the Application of the Genebank Standards for Plant Genetic Resources for Food and Agriculture: Conservation through Cryopreservation.
To facilitate this technology transfer, Jean also collaborated with Colorado State University and the USDA to build an open-access eBook Training in Plant Genetic Resources: Cryopreservation of Clonal Propagules, outlining each step of cryopreservation. It contains protocols, videos, and photos designed to help laboratories develop their own cryopreservation tools and help preserve crops across the world.
“We wanted to make this technology as transferable as possible.
“Cryopreservation shouldn’t be a mystery. I’m confident these resources will be a go-to for researchers for years to come.”
You can find the open-access cryopreservation eBook here and the FAO cryopreservation guide here. If you’re in viticulture and want to help protect our grapes, check out our Bachelor of Viticulture and Oenology, Master of Wine and Viticulture, and Graduate Diploma in Viticulture and Oenology.
Source: Lincoln University
