ARS Develops Speedy Method to Detect Major Sugarcane Disease

Researchers from the US Department of Agriculture’s Agricultural Research Service (ARS) have developed a method to rapidly detect ratoon stunting disease (RSD), an important disease that affects sugarcane production worldwide and causes 5 to 50 percent yield loss. RSD, caused by the bacterium Leifsona xyli subsp. xyli, is difficult to detect because it has no unique external symptoms so growers have no way of knowing if their fields have been infected.

Traditional ways of detecting RSD involve the use of antibodies. But due to the low concentration of the bacterium in the host, these methods have limited use when conducting a large-scale field RSD disease survey or RSD-resistance screening during breeding selection.

The method that the ARS scientists developed uses xylem sap to test for RSD. Bacterial DNA is extracted from the xylem sap and amplified via polymerase chain reaction. The plant’s xylem, the tissue responsible for the transport of water and soluble minerals from the roots throughout the plant, contains optimum concentration of the bacterium, making it an ideal area for collecting DNA. The ARS researchers said that the DNA-based method is more practical for laboratories throughout the world in detecting RSD, especially in developing countries, since it uses standard laboratory equipment and takes less time to complete.

The complete article is available at http://www.ars.usda.gov/is/pr/2009/090206.htm