Courtesy Bangkok Post
Recent reports suggest that many wild varieties of crops like maize, avocado, cotton, and potato are threatened with extinction. Overuse of herbicides and pesticides, along with land reclamation means that our root stocks are dwindling alarmingly. But hope is at hand in the crocodile-infested billabongs of northern Australia. By Jeremy Torr.
Brisbane, Australia. September 2021. Most of the rice we eat today – some 500 million metric tons a year worldwide – comes from highly bred varietals that have evolved and been cultivated from a range of wild rice grasses. These have existed in odd corners of the globe for tens of thousands of years, and are the foundation blocks for today’s rice varieties.
They have been taken and cross-bred with other species to give us the nourishing, fat grains we eat today, and are healthy, energy-rich and highly productive. But they are vulnerable. If a new disease – like the potato blight that decimated Ireland in the 1840s – arises, existing strains might lose the ability to fight of pests or fungi, resulting in a new rice famine.
So a rapid loss of wild rice variants could signal a big problem if anything goes wrong with our current cultivated gene stock. Additionally, newer rice strains also need ever increasing doses of chemicals and water to maintain their output. As researcher Rod A. Wing, director of the Arizona Genomics Institute at the University of Arizona, notes, the use of new genetic information could allow the world “to make crops that are higher yielding, more nutritious” but do less harm to the environment by using less water or pesticides.
“Making crops higher yielding, more nutritious but doing less harm to the environment” - Rod Wing. Courtesy UCal.
And guess where some newly-discovered, tough strains of unblemished wild rice have been found? In ponds across northern Australia – which are incidentally home to lots of big-toothed crocodiles. “Some of the best (wild) rice sites are where there are a lot of dangerous crocodiles,” says Prof. Robert Henry from the Queensland Alliance of Agriculture and Food Innovation in Australia. “They have probably been overlooked until now due to their location.” Understandably …
As Henry explains, some of northern Australia's wild rices “contain a wealth of untapped genetic diversity and at least two species are very closely related to domesticated rice.” This means they can be cross-bred with more highly developed strains, to give more hardy and drought-resistant crops. “Valuable traits from the wild rice such as drought tolerance and pest and disease resistance can be bred into commercial rice strains,” says Prof. Henry.
Other international researchers, including Wing, have researched more than a dozen domestic and wild rice species from around the world, and say the gene structure of the wild Australian variety (Oryza meridionalis) makes it highly likely these could be successful cross-breeding candidates.
Best place for wild rice? Where the crocodiles roam … Courtesy Whitsundays Cruises.
"These wild Australian rice genes could make commercial rice production better suited to northern Australian conditions,” explains Henry. "The wild rices could contribute resistance to diseases such as rice blast, brown spot and bacterial leaf spots too." The fact that most locations so far discovered that have surviving outcrops of O. meridionalis are in remote areas – and guarded by crocodiles in many cases – has ensured that no gene pollution has crept in from rice plantations further south in Australia. So that now, untainted samples of the sub-species are found only in northern Australia.
Professor Henry said that in addition to boosting global rice production, the new gene inputs from the wild rices offered the opportunity of cultivation of a tasty and nutritious product in its own right.
"It tastes good and we believe it may have more beneficial health qualities than other rice species," he said. Research has already shown the wild rice species has the lowest "hardness" of many cooked rices, and a higher amylose starch content too. “And the higher the amylose content, the longer the rice takes to digest," Prof. Henry said. "This potentially offers more nutrition to our gut microbes, in the same way high-fibre foods do." So it is more healthy too.
Prof. Robert Henry from the Queensland Alliance of Agriculture and Food Innovation. Courtesy QAAFI.
Henry notes that human trials will be needed to confirm the health benefits but initial tests indicate it is highly likely. Research is also continuing to study the rice’s family tree, but the research team is convinced that wild Australian rice is one of the most directly related species to the ancient ancestor of all rices.
"Through this research, we've developed a calibrated DNA-based molecular clock that maps when divergences in the rice genome have occurred," said Prof. Henry. "Few biological systems are as well described as rice now is."
“The world population could be 10 billion by 2050 and the question is how do we feed our world without destroying it,” said Wing. He is convinced that new genetic information such as that found in the wild Australian rices, could allow the world “to make crops that are higher yielding, more nutritious” but do less harm to the environment by using less water or pesticides.
Just keep clear of the crocodiles.