Response of wheat carrying 2NS/2AS, Rmg8 and Rmg7 translocation to Pyricularia oryzae pathotype Triticum from Paraguay.

Abstract

There are few known sources of resistance to Pyricularia oryzae B.C. Couch and L.M. Kohn in wheat, the major of which is linked to a translocation of the 2NS/2AS segment of Aegilops ventricosa, followed by other genes such as Rmg8 and Rmg7 located on chromosomes 2B (hexaploid wheat) and 2A (tetraploid wheat), respectively. The pathogen is also known to have host specificity and wide genetic variability; therefore, the objective of this study was to evaluate the phenotypic response of wheat carrying 2NS/2AS, Rmg8 and Rmg7 translocation to Pyricularia oryzae pathotype Triticum from Paraguay. The infections were evaluated with autochthonous isolates, indicating a resistance reaction for materials carrying translocation of the 2NS/2AS segment and a susceptibility reaction that was moderate to susceptible for materials with Rmg8 and Rmg7 genes, respectively.