David A Knorr

US Patent:

63161958, Nov 13, 2001

Filed:

Dec 23, 1999

Appl. No.:

9/471016

Inventors:

Reid D. Frederick - Ashburn VA
Paul W. Tooley - Braddock Heights MD
Morris R. Bonde - Middletown MD
David A. Knorr - San Leandro CA
Gary L. Peterson - Frederick MD
Norman W. Schaad - Myersville MD

Assignee:

The United States of America as represented by the Secretary of Agriculture - Washington DC

International Classification:

C07H 2104
C12Q 168

US Classification:

435 6

Abstract:

Karnal bunt of wheat is caused by Tilletia indica Mitra. Recently, teliospores morphologically resembling T. indica were isolated from bunted ryegrass seeds and wheat seed washes. Previously developed PCR assays failed to differentiate T. indica from the newly discovered ryegrass pathogen, T. walkeri. The nucleotide sequence of a 2. 3-kb region of mitochondrial DNA, previously amplified by PCR only from T. indica, was determined for three isolates of T. indica and for three isolates of T. walkeri. There was greater than 99% identity within either the T. indica group or the T. walkeri group of isolates, whereas there was approximately 3% divergence between isolates of these two Tilletia species. Five sets of PCR primers were made specific to T. indica, and three sets were designed specifically for T.