APS Homepage

POSTERS: Host resistance screening

Evaluation of global collection of triticale to Pyrenophora tritici-repentis(tan spot) races 1, 5, and Ptr ToxA
Shaukat Ali - South Dakota State University. Karl Glover- South Dakota State University, Sunish Sehgal- South Dakota State University, Mohammed Abdullah- SDSU, Sandeep Kumar- South Dakota State University, Emmanuel Byamukama- South Dakota State Univ

Triticale (× TriticosecaleWittm. ex A. Camus.)serves as an excellent choice for cover crop and buildssoil health. It has also served as a bridge between wheat and rye to bring resistance genes to many fungal diseases into wheat. Triticale is generally considered less prone to biotic and abiotic stresses; however, it has shown susceptibility to leaf spot diseases including tan spot, caused by the fungus Pyrenophora tritici-repentis(Ptr). The objective of this study was to characterize triticale germplasm for its reaction to Ptr race 1, race 5, and Ptr ToxA. A global collection of 366 triticale genotypes representing 21 countries was obtained from USDA- Small Grain Germplasm Bank, Aberdeen, ID. Two-week-old seedlings of all 366 genotypes were inoculated individually with a conidial suspension of Ptr race 1 and 5 under controlled greenhouse conditions. Also, three leaves of each genotype were infiltrated with Ptr ToxA. The evaluated genotypes exhibited a range of reaction from susceptible, moderately susceptible, moderately resistant, and resistant to both races. About 50% of the evaluated genotypes showed sensitivity to Ptr ToxA. Our results indicate that triticale varies in its reaction to tan spot, therefore when employing triticale genotype for wheat improvement caution should be taken to avoid accidentalincorporation of tan spot susceptibility.