Wheat Genotypes that Develop Both Tan Necrosis and Extensive Chlorosis in Response to Isolates ofPyrenophora tritici-repentis

Abstract

Wheat cultivars commonly develop either tan necrosis (nec) or chroloris (chl) in response to infection by Pyrenophora tritici-repentis. We report, for the first time, wheat genotypes capable of developing both symptoms. Isolates of P. tritici-repentis can be classified on the basis of their ability to induce tan necrosis and/or extensive chlorosis. A selection of winter wheat cultivar Norstar and spring wheat line 6B699, tested to isolates from pathotypes 1(nec+ chl+), 2(nec+ chl-), 3(nec- chl+), and 4(nec- chl-), developed tan necrosis in response to nec+ isolates as well as extensive chlorosis in response to chl+ isolates (.)