Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2003
Publication Date: 6/1/2003
Citation: ALI, S., CARTWRIGHT, T., FRIESEN, T.L., RASMUSSEN, J., MILUS, G. NOVEL PYRENOPHORA TRITICI-REPENTIS ISOLATES FROM ARKANSAS WHEAT. AMERICAN PHYTOPATHOLOGICAL SOCIETY ABSTRACTS. 2003. V. 93(6) p. S3.
Technical Abstract: Pyrenophora tritici-repentis, causal agent of tan spot of wheat, occurs in nature as multiple races based on ability to cause necrotic (nec+) and chlorotic (chl+) lesions on wheat differentials. Tan spot occurs in Arkansas, but the race structure in that population has not been investigated. Fifty-one single-spore isolates, obtained from diseased leaves in 2002, were identified to race. Twenty-eight isolates were race 1 (nec+ chl+), but 23 isolates produced a novel reaction consisting of nec- chl+ on ND495, Katepawa, and 6B365, and avirulence on Glenlea, Salamouni, and M-3. Additionally, 17 of the 23 isolates lacked ToxA. The 23 isolates appear to form a new race. The data indicate that P. tritici-repentis in Arkansas has similarities to and differences from races in other regions of the US. Additional collections from Arkansas wheat will be made in 2003 for further testing.