Australian scientists have just tested a new strain of wheat that could increase yields in saline soils by 25%. The news comes just as Oxfam warns of catastrophic drought and potential famine in the west African desert regions, and is a reminder that we face an increasingly hungry world. Global warming and rising sea levels present a challenge for everybody. Just 11% of the planet's land surface is suitable for agriculture, and a lot of this land is being steadily degraded by salination.
Salts tend to accumulate wherever soils are irrigated, and ever higher tides will mean that huge tracts of now fertile estuary farmland – for instance in the Nile delta, and in Bangladesh – are increasingly at risk from catastrophic flooding or slow poisoning with brine. Extremes of heat, too, tend to depress crop yields. The Australians report in Nature Biotechnology today that they identified a salt-tolerant gene in a wild wheat ancestor, and bred it into durum wheat, the basis of pasta, noodles, couscous and a lot of bread too. They used traditional techniques to transfer the gene, thanks to increasingly precise knowledge of the molecular biology and biochemistry of plants. Researchers have sequenced the genomes of around 30 plants, among them wheat, soybean, rice, maize, millet and potato.
These are the staples of seven billion people right now: can they feed the nine billion expected to occupy the planet by 2050? Agriculture's old enemies – rusts, blights and mildews, aphids, weevils and locusts – are tenacious and swift to find new weakness, and beyond climate change there are other, more intractable, challenges to food security. Two billion extra souls will need somewhere to live, which means that precious farmland will disappear under pavement, or be quarried for minerals. As fuel prices rise and oil supplies become precarious, so it becomes more profitable to grow sugar cane or corn as feedstock for biofuel for the Toyota, rather than food for the table. The rising middle classes in China and other fast-developing nations have begun to develop a taste for expensive steak at the cost of cheap and nourishing grain and pulse, and water too. So farmers are going to need every bit of ingenuity to keep delivering the bread, rice and beans for the table.
Food is the one item expected in the markets on a daily basis : any technology that can, in the words of Jonathan Swift, make two ears of corn or two blades of grass grow where one grew before is welcome. The new wheat was achieved by traditional cross-breeding but it represents a significant genetic modification, however we label it. The big question should be: who benefits? This is science in the service of those who need it most.