AbstractThe purpose of this study was to elucidate the genetic cause for the lack of express ion of the geneHt2againstExserohilum turcicumrace 2 on certain genetic backgrounds related to the inbred line B14. Two such inbreds (A635Rp and B59), susceptible to this pathogen were crossed onto the inbredOh43—‐Ht2Ht2. The following generations: F1, F2, F3, F4, backcrosses to both parents, selfings of the backcrosses, in addition to the parent lines, were evaluated forHt2expression in this study. Plants of each generation were inoculated withE. turcicumrace 2 and evaluated for the expression of the chlorotic‐lesion resistance determined by the geneHt2. In spite of the reported dominance ofHt2on some genetic backgrounds, the F1generations studied here did not showHt2resistant lesions. The data presented herein suggest that B14and related inbred lines carry a dominant gene(I) that inhibits the expression of theHt2gene. Chi‐square analyses of the reactions of 108 progeny families studied supported this hyp