Fine-tuning wheat genomes would help regional wheat varieties feed a growing population by potentially doubling global production.
In a groundbreaking analysis of wheat’s untapped genetic potential undertaken by an international team of experts, global yields have been shown to be only half of what they could be.
The team, led by UK research Rothamsted, said this “genetic yield gap” could be closed by developing wheat varieties suited to each region using the vast genetic variation available in global wheat genebanks and history with modern techniques, such as rapid selection. and gene editing.
Dr Mikhail Semenov and Dr Nimai Senapati, who co-led the study, defined a crop’s “genetic yield potential” as the highest yield that can be achieved by an idealized variety – in other words terms, a plant with an optimal genome that allowed it to capture water, sunlight and nutrients more efficiently than any other.
Dr Semenov said: “Current wheat cultivars are, on average, only halfway to the yields they could produce given the mismatches between their genetics and local wheat growing conditions. World wheat production could be doubled by genetic improvement of local wheat cultivars, without increasing world wheat acreage.
Researchers ran millions of computer simulations to design “perfect” wheat plants suited to local environments. Compared to the performance of locally adapted cultivars, in all cases they found that current wheat varieties underperform for grain yield.
Closing the genetic yield gap would go a long way to feeding the world’s growing population and reduce the pressure to convert wild habitats to farmland, says Dr Senapati.
Wheat is the most widely grown crop in the world and, in terms of human consumption, it is the second most important crop after rice, with global harvests of around 750 million tonnes. Since the ‘green revolution’ of the 1960s, yields have, on average, tripled – but this study suggests there’s more to come.
This is the first time this kind of analysis has been done on a global scale with the study, published in Nature Food, looking at a total of 53 wheat growing regions in 33 countries and covering all global growing environments. wheat.
Using a state-of-the-art wheat model, called Sirius, the team first calculated the potential yield of a total of 28 commonly used wheat varieties grown at these sites, assuming the best growing conditions. possible for each. This resulted in harvests of less than 4 tonnes in Australia and Kazakhstan – compared to 14 tonnes of wheat produced per ha in New Zealand.
Then, they “idealized” the local varieties within the model, optimizing several plant traits that contribute to yield and whose underlying genetics would allow them to be improved by plant breeders.
The results showed that by optimizing key traits, genetic yield gaps could be 30-70% in different countries, with a global average genetic yield gap of 51%. Therefore, global wheat production could be doubled by exploiting this existing genetic yield gap to achieve global food security in a sustainable manner.
“It is not surprising that countries with the lowest current yields could benefit the most from closing their genetic yield gaps,” Dr Senapati said. “That said, even improvements in countries with an average genetic yield gap of 40-50%, but with a large proportion of the world’s wheat crop area – such as major producers India, Russia, China, the United States, Canada and Pakistan – would have a substantial effect on global wheat production due to the larger wheat acreage involved.
Prior to this study, the size of these national and global genetic yield gaps was unknown. The idea of genetic yield gap contrasts with the older concept of traditional yield gap due to sub-optimal management where harvests are less than the best-case scenario due to factors such as pests or diseases, lack of nutrients, or planting or harvesting at the wrong time.
“Our analysis suggests that these genetic yield gaps due to suboptimal genetic adaptation could, in relative terms, be as large as the traditional yield gap due to imperfect crop and soil management,” said Dr. Semenov.
The study also involved leading wheat experts from Australia, Denmark, France, Germany, the Netherlands and Mexico.