Biotech Updates

ARS Releases Corky Root-Resistant Lettuce Lines

July 10, 2009

The US Department of Agriculture's Agricultural Research Service (ARS) has released three new lettuce breeding lines with resistance to corky root, a serious lettuce disease caused by the bacterium Sphingomonas suberifaciens. Infection of the bacterium causes lettuce roots to expand and develop yellow to brown lesions and longitudinal cracks, taking on a cork-like appearance. This results to severe yield loss since the roots are unable to effectively absorb water and nutrients.

The corky root-resistant lettuce lines, developed by ARS scientist Beiquan Mou, also showed little to no tipburn in test trials. Tipburn is caused by calcium deficiency in young, growing leaves. This defect severely limits the appearance and shelflife of lettuce, especially if the lettuce is to be used for salad mixes as there is zero tolerance for defects.

For more information, read http://www.ars.usda.gov/is/pr/2009/090707.htm