Drought Relief Spelled "A-E-R-E-N-C-H-Y-M-A"

A cork-like tissue found in the roots of prairie grass could dramatically improve crop yields on drought-prone farmland in the United States.

The tissue, called aerenchyma, enables roots to penetrate tough soil layers that otherwise would restrict their growth on more than 250 million acres in the U.S. and about 10 billion acres worldwide.

In the southeastern United States, for example, these layers stop wheat plants’ roots from obtaining vital moisture and cut winter wheat yields from a potential 100 to 200 bushels per acre to 30 to 35 bushels. Farmland that might produce tremendous yields of wheat, corn or soybeans has been planted with trees or simply left fallow because of the combination of drought and restrictive soil layers.

Aerenchyma is not a new discovery, but interest in the corky tissue intensified two years ago when Richard W. Zobel, a plant geneticist with USDA’s Agricultural Research Service in Ithaca, N.Y., found it in Eastern gamagrass, a prairie grass that thrived during killer droughts in Missouri.

The discovery has led ARS scientists to emphasize the aerenchyma trait in breeding programs for several crops. They expect to release commercial varieties of wheat with aerenchyma within two years and soybeans in five years. Corn is another likely candidate since it is a close relative of Eastern gamagrass. Aerenchyma is already very common in sugarcane, but ARS scientists are working on breeding improvements.

An article about aerenchyma appears in the August issue of Agricultural Research magazine, the monthly publication of the Agricultural Research Service. The article can be viewed on the World Wide Web at:

/is/AR/archive/aug97/aerenchyma0897.htm

Scientific contact: E. Eugene Alberts, Acting National Program Leader, Soil Management, ARS, USDA, Beltsville, Md., phone (301) 504-5016, fax 504-5467, e-mail eea@ars.usda.gov