Time to open the Gondwana store 

2 January 2019

By Brad Collis

Robert Henry gazes ruefully northwards from the University of Queensland’s St Lucia campus, caught between feeling excited and a niggling regret.  

“There’s a supermarket out there … but most Australians don’t even know it,” he said.  

Wild parsnip growing in northern Australia © Shutterstock

His excitement stems from this ‘supermarket’ being the enormous untapped food and cropping potential of countless indigenous plant species that a small, though growing, body of scientists are realising could be a genetic bounty holding a critical key to the planet’s food security. Internationally, northern Australia in particular, is already being talked about as the frontier for new plant genetics. Robert Henry’s regret is that by-and-large it remains a blind spot for Australians. Most of the interest and research is being driven from overseas. 

“Take wild rice which is abundant across northern Australia from Townsville to the Kimberley. I’m considered the local expert, but most of what I know is from Japanese scientists who have been studying our wild rice for 20 years,” he said. 

Robert Henry, Professor of Innovation in Agriculture and Director of QAAFI said it is becoming increasingly clear that Australia is home to an enormous diversity of indigenous grain-bearing grasses, pulses and fruits of potentially huge value to plant breeders needing to bolster domesticated crops with increased climate resilience and pest and disease resistance. 

“We have rice, ancestral grasses related to domesticated cereals, our own soybean, sorghum, mungbean, pigeon pea; even citrus and grapes, but they have mostly been overlooked because of a long-held, false, assumption that our only food crops are those introduced through European settlement.” 

Professor Henry believes this landscape ignorance may have arisen from a basic misunderstanding of the Aboriginal use of these plants. “It was often noted by explorers and settlers that indigenous people didn’t undertake any traditional cultivation; the conclusion being that there were no crops to farm. Now, however, we are beginning to realise that indigenous plants bearing edible seeds and fruits were in such abundance naturally that a transition to farming, in the European sense, just wasn’t required. 

“For example, native rice is present in such abundance and in naturally weed and disease-free stands that you don’t need to plant it and manage it. You just harvest and store … activities that were observed and recorded, but not understood. We were blinded to the significance of this by our need to see crops being cultivated.” 

Professor Henry is now working on a project for the CRC for Developing Northern Australia to scope the potential for a rain-fed rice industry in the north based on local genetics: “We have learned that when we take Asian varieties into the north they only grow until pests and diseases find them. Native rice doesn't have this problem, which points to an opportunity to identify these resistance genes and back-cross into a high-yielding Asian rice. 

He describes native species as “unknown, underutilised, underappreciated”; a perspective he hopes to help change. 

A measure of the opportunity (and historical ignorance) is DNA analysis is revealing that some of the plants like rice and soybeans (genus Glycini) that were assumed to be wild survivors of species introduced by early human migration, actually originated here.  

Australian wild rice, for example, was assumed to have been brought to Australia from Asia and this may be why it has been ignored by breeders. However, research has now shown the Australian varieties are quite distinct and therefore likely to possess considerable genetic diversity that hasn’t been captured in domesticated varieties. 

Such potential locked up in native germplasm is now one of Professor Henry’s primary interests in his agricultural innovation portfolio. 

“It’s the same with soybean. There is an increasing realisation that most of the genetic diversity for Glycini is right here. We’ve found at least eight species in Queensland alone that we have yet to even name,” he notes. “And all the timee we have been struggling to adapt introduced varieties to our variable climate … we’ve had our own.” 

Professor Henry is also studying wild sorghum in a joint project with Professor Ros Gleadow from Monash University in Melbourne: “The sorghum we grow commercially was domesticated in Africa, but the sorghum genus is Australian. All of the species exist here, mostly in Queensland, but apart from a Texan variety that has used genes from a wild Queensland sorghum, this resource also has largely been overlooked even though we have identified traits that could deliver bigger grains and help get sorghum into the human foods market.” 

Native citrus has gained some recognition through the finger lime, Citrus australasica,  

and the round lime, Citrus australis. Professor Henry said there are four Australian citrus species and all potentially have useful disease-resistance traits for domesticated species, as well as an early flowing trait that the American citrus industry has exploited to breed earlier fruiting trees.  

Other fruits include wild grapes found to be of Gondwana origin – the super continent that split-up about 180 million years ago to form the landmasses we know today as Australia, Africa, South America, Antarctica, the Indian subcontinent and the Arabian Peninsula. Professor Henry said the grapes’ adaptation to a rainforest environment in Queensland has made them resistant to fungal pathogens: “This could provide the modern-day industry with some very exciting rootstock potential.” 

Another example of this extraordinary unfolding story that is destined to re-write Australia’s agricultural history is pigeon pea. Australian farmers have been trying to build production to supply potentially high-value markets on the sub-continent, but the introduced varieties have struggled under pest and disease pressure. Now it has been found that most of the global biodiversity for this plant exists in an agroecological zone stretching between Townsville and Mount Isa. Again, the genetics that could protect the commercial crop are already here. 

What all this amounts to, said Professor Henry, is the presence in Australia of indigenous genetic resources that have the potential to improve crop performance – in Australia production systems and elsewhere. 

He believes that exploiting this resource would herald a second Green Revolution. The first Green Revolution, in the 1960s, used selective breeding to increase the ratio of grain to plant matter (the higher harvest index approach). Professor Henry believes there is as much to be gained again by capturing wild diversity that hasn’t yet been incorporated into domesticated crop gene pools. 

Serendipitously with the growing awareness of this potential is the advent of new breeding technologies: “Until now we simply haven’t had the tools, but modern pre-breeding allows us to accurately identify, and bring in, those genes and use genome sequencing and analysis to guide rapid back-crossing. 

“It’s an exciting new opportunity for agriculture because a lot of what we are growing today is based on something that was domesticated 10,000 years ago. Faced with climate change we have to broaden that genetic base. Exploiting the biodiversity existing in indigenous crops that are related to many introduced commercial varieties is one such technological opportunity, but right now there isn’t any concerted effort to research this potential.”  

However, Professor Henry is confident this will change, especially if the national mindset can be moved from asking ‘what do we have’ to ‘what don’t we have’. 

“That’s exciting because the evidence is mounting that we probably have a bit of everything.” 

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