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Poster: Diseases of Plants: Disease Detection & Diagnosis


Race characterization of Pyrenophora tritici-repentis population from Lithuania and Romania
A. SIDRAT (1), S. Ali (2), Z. Liatukas (3), M. Ittu (4), S. Sehgal (2), N. Kaur (2) (1) South Dakota State University, Brookings, SD, U.S.A.; (2) South Dakota State Universty, Brookings, SD, U.S.A.; (3) Institute of Agriculture, Lithuania Research Center

Tan spot, caused by Pyrenophora tritici-repentis (Ptr) is an economically important disease of wheat. Eight races exist of this fungal population. In this study, 223 single spore isolates from Lithuania (n=114), and Romania (n=109) were evaluated for their race structure through genotypic and phenotypic characterization. Molecular variation was identified through PCR with Ptr ToxA and Ptr ToxB genes specific primer. Of these 223 isolates genotyped, 110 isolates were further phenotyped by inoculating them individually on two-week old seedlings of tan spot wheat differentials Glenlea, 6B365, 6B365, and Salamouni. Nearly 86% (191/223) isolates genotyped contained ToxA genes. Phenotypic characterizations on 110 isolates identified 69, 6, 13, and 4 isolates Ptr race 1, 2, 3, and 4, respectively. Eighteen of 223 isolates lacking in Ptr ToxA gene could not fit into currently identified 8 races as they produced necrosis on Glenlea and chlorosis on 6B365. These results indicate that a diverse Ptr population exists in Lithuania and Romania. This information would help the regional wheat breeding programs in the development of durable tan spot resistance cultivars.