Lisa Castlebury

Objectives

Each year billions of dollars of agricultural losses are caused by fungal diseases of crop plants. Bunt and smut diseases of wheat and other grass crops have resulted in an estimated $2 billion loss in crop yield and lost export markets in 1996 and 1997 alone. The systematics of Tilletia and other smut fungi are poorly understood at best. The discovery of Karnal bunt (Tilletia indica Mitra) on wheat in the United States precipitated a crisis particularly in the wheat export market due to the strict quarantine placed on this fungus. This problem was exacerbated by the discovery of a morphologically similar Tilletia on species of ryegrass (Lolium perenne and L. multiflorum) that was discovered in wheat/ryegrass seed mixes. The focus of my research is the morphological and molecular differentiation of T. indica, the Tilletia sp. on Lolium, the T. barclayana complex, and other similar Tilletia species. Scanning electron and light microscopy as well as molecular techniques such as the polymerase chain reaction (PCR) and ribosomal DNA sequencing are being used to differentiate these fungi.

Bunt Fungi Database

CRIS Project: 1275­22000­022­00D

Agricultural Research article (May 2006): ARS Experts as Firefighters: Our scientists respond to international agricultural problems that affect the United States