Scientists believe that global wheat production could be doubled by accessing into the crop’s “untapped genetic potential”.
By using modern techniques such as speed breeding and gene editing, the international team behind the new research say that it would be possible to cultivate new varieties of wheat tailored to each region that they’re grown in.
Depending on their genes, different varieties of wheat capture water, sunlight and nutrients in different ways. The scientists propose that with an optimal genome wheat crops would be able to deliver a higher yield of grain per acre.
The study, led by the UK’s Rothamsted Research, used existing data on how different genes contribute to individual plant traits “such as size, shape, metabolism and growth”.
They ran millions of simulations to effectively design the perfect wheat plants suited to their local environments. Comparing these to locally adapted cultivars, they found in all cases that current wheat varieties were underperforming for grain yield.
Dr Mikhail Semenov, one of the study’s leads, said: “Current wheat cultivars are, on average, only at the half-way point with respect to the yields they could produce given the mismatches between their genetics and local wheat growing conditions.
“Global wheat production could be doubled by the genetic improvement of local wheat cultivars – without increasing global wheat area,” he added.
Fellow study lead Dr Nimai Senapati said that improving this “genetic yield gap” would both help feed the world’s growing population and reduce the pressure to convert wild habitats to farmland.
Humans have farmed wheat for millennia and the impact on our species has been enormous – agriculture is often described as the first revolutionary step in human civilisation as it led to settlements and evolved social structures.
Today wheat is the most widely grown crop in the world and second only to rice in terms of human consumption, with global harvests in the region of 750 million tons.
The new study published in the journal Nature Food looks at 53 wheat growing regions across 33 countries, covering all of the global wheat growing environments.
The team first calculated the potential yield from 28 commonly grown wheat varieties at each of these sites, assuming the best cultivation conditions were in place for each one.
The harvests this delivered varied enormously, with less than four tons per hectare in Australia and Kazakhstan, with 14 tons per hectare in New Zealand.
But these were improved by replacing the local cultivars with the idealised varieties of wheat favouring particular traits, such as “tolerance and response to drought and heat stresses, the size and orientation of the light-capturing upper leaves, and the timing of key life cycle events”.
According to the study, by optimising these key traits, the global average genetic yield gap could be closed by 51% – meaning global wheat production could be doubled.
“Not unsurprisingly, the countries with the lowest current yields could gain the most from closing their genetic yield gaps,” said Dr Senapati.
“That said, even improvements in those countries with a medium genetic yield gap of 40 to 50%, but with a large proportion of global wheat harvest area – such as the leading producers India, Russia, China, USA, Canada, and Pakistan – would have a substantial effect on global wheat production due to the larger wheat cultivation areas involved.”
According to the researchers, before this study it was not known how large the genetic yield gaps were at a country and global level.
They say this concept of a genetic yield gap contrasts with the existing and more traditional view of a yield gap which compares harvests to how they could have performed under optimal management “as a result of factors such as pest or diseases, lack of nutrients, or sowing or harvesting at the wrong time”.
“Our analysis suggests that such genetic yield gaps due to sub-optimal genetic adaptation could, in relative terms, be as large as the traditional yield gap due to imperfect crop and soil management,” said Dr Semenov.
“Wheat was first domesticated about 11,000 years ago, but despite this – and not to mention the sequencing of its entire genome in 2018 – the crop is still some way from being at its ‘genetic best’,” he added.