COLUMBIA, Miss., Dec. 27 (UPI) -- Scientists are using genetic research techniques to help develop new aluminum-tolerant wheat strains that can grow in poor, acidic soils and help feed the world's ever-growing population. The researchers are breeding the wheat conventionally but are monitoring genetic markers to help speed the lengthy process.

When soil is acidic, more aluminum becomes chemically available just below topsoil. Roots are unable to penetrate such soil and generally wheat dies. Aluminum impairs plant growth on nearly 2.5 billion of the world's 8 billion acres of cropland, including about 86 million acres in the United States. One way to increase yields is to make the soil less acidic by adding lime, but lime is expensive to transport over long distances.

"We're going rapidly from 6 billion to 9 billion people in 40 years, according to U.N. projections. Can we or can't we feed them?" said lead researcher Perry Gustafson, a geneticist at the U.S. Agricultural Research Service's Plant Genetics Research Unit in Columbia, Miss. "We'll have to depend increasingly on acidic, high-aluminum soils. If there's any way some of that soil can be made useful without damaging the environment, then we should have the biotechnology to do so."

"I'm not aware of anything that likes aluminum unless it holds their beer," Gustafson said in an interview with United Press International. "Unfortunately, aluminum's one of the most abundant metals in the world, so we have to find ways of growing wheat in aluminum."

The researchers believe that aluminum tolerance genes borrowed from rye may prove wheat's best hope for adapting to acidic soils. Some varieties of rye can tolerate seven times the level of aluminum that wheat can.