A team of researchers from The Chinese University of Hong Kong, BGI and other institutes have identified a gene of wild soybean linked to salt tolerance, which they claim could help breading programmes create crops for growth in saline soil.

Their study, published online in Nature Communications, could provide a strategy for crop improvement, according to its authors.

Due to domestication and human selection, cultivated soybeans have less genetic diversities than their wild counterparts. Among the lost genes, some may play important roles for the adaptation to different environments.

The dwindling genetic diversity associated with conventional agriculture has been cited as one of the model's most severe shortcomings; genetically similar crops will all be more susceptible to a given disease or an effect of climate change.  

Scientists, including those in the BGI study, have looked at crop plants' wild relatives – such as the wild soybean – as potential resource for investigating the valuable genes that adapt to certain environmental conditions.

The researchers identified the newly discovered gene's role in salt tolerance, and speculated that it could have been bred out of crop plants through "negative selection against a stress tolerance gene in unstressed environments." The expression of stress tolerance genes may be an energy burden on the plant if the functions of these genes are not required.

The gene (called GmCHX1) could be used by crop breeders to help address the problem of salinisation, which is a growing problem worldwide, particularly in irrigated areas with low rainfall.

It is expected to worsen in areas where rain will become scarcer as a result of climate change. Although arid regions of Asia, Australasia and South America are most at-risk of  salinisation, in Europe the effects are also being felt; 3% of Spain's 3.5Mha of irrigated land is already 'severely affected', according to the EU Joint Research Centre, and another 15% is seriously threatened.