VARIABILIDAD EN LA RESISTENCIA A MANCHA AMARILLA EN GENOTIPOS DE TRIGOS PRIMAVERALES DE DIVERSOS ORÍGENES.

Tan spot caused by Pyrenophora tritici-repentis (Died.) Drechs. (anamorph Drechslera tritici-repentis (Died.) Shoem.) is one of the most important wheat diseases. The aim of this work was to generate information about variability of the resistance to tan spot in a population of spring wheat genotypes. Field experiments were carried out in 2014 at the Experimental Station Julio Hirs chhorn, National University of La Plata. The experimental design was a split-plot with two replications. The main plots were two isolates of P. tritici-repentis. Subplots were 110 spring wheat genotypes. Severity evaluation was performed in seedlings as the area affected with necrosis and chlorosis. Genotypes and isolates significanlty influenced the disease severity. Los Hornos isolate was more aggressive than Gualeguaychú isolate . Severity ranged between 18,4% to 78,7%. Some genotypes showed better performance against one of the isolates. The high variability in resistance to tan spot found could be used in breeding to improve the resistance to the disease. [ABSTRACT FROM AUTHOR]