Detection and inheritance of leaf rust resistance in common wheat lines Agra Local and IWP94

Genetic studies were undertaken to determine the number and identities of leaf rust resistance genes in common wheat lines Agra Local and IWP94. The infection type arrays of the two lines with eight pathotypes (pt.) of P. triticina were different from those of lines possessing known leaf rust resistance (Lr) genes. Agra Local possessed two recessive resistance genes, one conditioning resistance to pathotype 4R9-7, and the other, a temperature-sensitive factor, gave resistance to pt. 121R127 at high temperature (27°C). IWP94 was previously demonstrated to carry Lr23. From the present study IWP94 was determined to have at least four leaf rust resistance genes. The first of these was the same recessive gene conferring resistance to pathotype 4R9-7 which was found in Agra Local. A second partially dominant gene conferred resistance to pathotype 121R127 at high temperature and two additional recessive genes governed resistance to pathotype 93R15. When present together, these two recessive genes complemented each other and provided resistance to pathotype 69R13 as well. One of the two recessive genes conferring resistance to pathotypes 93R15 and 69R13 was Lr23.