The Australian PlantBank

This story about seeds could have started anywhere on earth, at any time. It could have started on my grandfather’s farm in the 1960s when my young uncle accidentally fed some wheat seeds that had won first prize at the Sydney Royal Easter Show in 1931 to the chooks; in the early 2000s with my mum standing on the back of a ute collecting seed from locally endemic eucalypts for her propagation nursery; or even 32,000 years ago when the seeds of a small Siberian plant (Silene stenophyllaz) were buried by an ice age squirrel. Genetic material from the seeds was extracted in 2012 and used to germinate new plants – making it the oldest plant ever to be regenerated.

Seeds have been collected formally and informally by humans and animals since the beginning of time. But let’s start somewhere closer to home – The PlantBank at the Australian Botanic Garden in Mount Annan. PlantBank is a horticultural research facility housing a seed bank and research laboratories specialising in the conservation of Australian native plant species. I recently visited the facility and had a fascinating chat with the Principal Research Scientist, Cathy Offord.

‘The aim of the PlantBank project is to conserve, in some form or other, all the plant species of NSW,’ Cathy tells me. ‘There are some 6,000 known species and we want to conserve them either in the garden, the seed bank, in tissue culture, or in a closed storage facility.’

The PlantBank facility is relatively new. It was designed by architecture firm BVN, with landscape architecture by 360 Degrees, and was opened in 2013. Positioned on a rise in the landscape and framed by native meadow planting, it’s got serious street presence. Wandering into the building, past the (very brilliant) lichen garden, the mirrored façade reflects the surrounding landscape planted with locally endemic plant species. Once inside the building itself it’s clear PlantBank is as much about science as it is about education. Visitors are encouraged to interact with the scientists and watch them at work through the glass windows.

The building was designed to engender the cross-pollination of sciences and education,’ says Cathy.

‘People are amazed by what they see here. The facility is very scientific but it’s also alive. All the spaces in PlantBank were designed so visitors can see into the labs where scientists are working. The staff love it!’ Whilst the scientists aren’t obliged to talk to visitors, Cathy tells me the level of interaction is enjoyed by staff, simply because they’re really proud of their work. ‘It feels more relevant to them if people can see what they’re doing,’ she says.

The interactive 'Diversity' wall display at PlantBank
A notebook used by the PlantBank seed collectors.
Protecting Persoonia spp. fruits from hungry mouths!

Seeds have traditionally been saved for two primary reasons – for agriculture and conservation. Like my grandfather with his prize-winning wheat seed from 1931, farmers the world over have traditionally kept seed from good crops and used it the following year, repeating the process over and over. By doing this, the farmer ends up with a plant that is best suited to the local environment and growing conditions. It also means genetic diversity – each farmer’s wheat crop will be slightly different to the next. And diversity is the spice of life, as someone once said!

Saving seed for conservation, rather than agriculture, is the focus at PlantBank, and Cathy and her team are all over it.

The processes that just one seed goes through at PlantBank are amazing – seed is collected, cleaned, tested for viability, entered into a big database, packed, and then finally placed in the seed vault, a super-sized cool room or freezer room, depending on the seed.

It’s hard to fathom the web of information required for each single species in order to conserve it successfully. Every little thing about the plant has got to be understood by the scientists – like what the best temperature is for the seed to germinate, exactly what conditions the seed needs for germinating, what the best way to store the seed is, how it interacts within an ecosystem, and more. It’s mind-blowing, time consuming, and hugely important work.

On the day of my visit I chatted to a scientist working on Persoonia acerosa. ‘There’s a very high proportion of Persoonia species that are on the threatened species list,’ she says. ‘Persoonia acerosa is important as it has big fruits – not many other species provide that much food mass so for bigger mammals and birds they’re an important food source. Ecologically, they’re really important.’ Yet, they’re tricky to propagate from seed. The scientists are testing all sorts of things – like feeding the seeds to emus to see whether that will help break down the endocarp, or outer seed casing. The only downside of this process is the sorting through emu poo to find the seeds!

‘The questions we’re trying to answer are; what does it take to break the endocarp down, how long will they survive in the seedbank, and what stimulates germination. There’s a whole bunch of questions, and the answers will likely vary between different Persoonia species. It’s endlessly fascinating,’ Cathy says. These are questions that need to be answered for every single species studied at PlantBank!

Once they’re answered, the seeds are packaged in collections of around 10,000 seeds and taken to the drying chamber. ‘The critical thing about seed banking is to get the seeds dry enough so that they don’t explode like a bottle of beer in the freezer,’ says Cathy. Once sufficiently dry (and of course, some seeds don’t like being as dry as others, so the scientists need to understand this as well!), the seeds are then stored in the vault. Each plant has a certain amount of time it will survive in the freezer, so the scientists need to manage this variable as well, so they know when to replenish the collection.

Seed banks, like the one at PlantBank, are a botanical and ecological insurance policy. Clearly it’s best to conserve plants in their natural environment, but we don’t have a particularly good track record at that. Collecting and storing seed in seed banks means it can then be used for research, restoring habitats, and even reintroducing threatened species back into the environment. It’s really important work yet sometimes it’s hard to see the links between it and our every day lives. How does conserving one obscure native plant species restricted to a small area of NSW affect the way we live, and the way our children live in the future?

For me it comes back to just three words: Everything is connected. This isn’t some lofty metaphysical idea but an absolute fact. And this is why conservation is important. If Persoonia acerosa disappears, what will happen to the animals that rely on it for food? And what about the animals that eat them? And the plants that rely on those animals to process their seeds for germination? And on and on and on.

Poet Stanly Kunitz says it best: ‘The universe is a web, touch it at any point and the whole web quivers.’

The PlantBank’s website is here.

Cathy Offord, principal research scientist at PlantBank