Seed lab using liquid nitrogen to save natives opens in Wellington

A seed lab has opened at Otari-Wilton's Bush, funded by Karori Lions Club, meaning Ms van der Walt can work on ensuring a future for some of our at-risk native trees every day.

"It's overwhelming but also very exciting to be able to contribute," the scientist said.

The science is ground-breaking for New Zealand.

The experiment uses liquid nitrogen to store fleshy seeds from the swamp maire, which is threatened by the potentially-fatal myrtle rust disease. The traditional drying and freezing method kills the seeds.

The pressure's also on to successfully store the seeds because climate change is expected to have an effect on plant diseases in New Zealand.

Ms van der Walt said the lab and opportunity to bring other staff to the lab to help with the experiment during the swamp maire's next seeding period means she'll be able to find the right method quicker.

"I'm really positive we'll have an answer, we will get survival by next year," she said.

Australia, the Pacific and Asia are set to benefit from the results of the experiment, as these areas all have syzygium species at risk from myrtle rust, Ms van der Walt said.

At the moment, none of the seeds in the lab have made it through the second liquid nitrogen application.

Other natives that can be stored traditionally will also benefit from cryopreservation as it's more effective at freezing metabolic activity inside the seed and means seeds can be stored for much longer than the traditional method, Ms van der Walt said.

Ms van der Walt is also experimenting with Bartlett's rata, which has been grown in the lab after hand-pollination between genetically diverse trees.

The lab is also working with Te Papa Museum to boost stock of the species, which is New Zealand's rarest and also at risk of myrtle rust.

There's now more seedlings in the lab then trees left in the wild.

"They won't recover in the wild, they will literally go extinct if we do no work like this," Otari-Wilton's Bush team manager Rewi Elliot said.

There's already been success in the lab for another project - improving the germination of the Hinau tree.

Wellington City Council's plant nursery has only had one seedling in a seven year period when seeds from the tree were planted.

But in the lab, soaking and drilling into the seeds has led to better results.

"In two months already... five seedlings germinating in our experiment so showing we're down the right track with that one," Ms van der Walt said.

Orchid species are the next natives on the list in need of a boost from science.

"The end goal would be that we don't have a need for the seed lab... we put ourselves out of business," Rewi Elliot said.