Leaf rust and stripe rust resistance genes derived from Aegilops sharonensis

Linked leaf and stripe rust resistance genes introgressed into hexaploid wheat from Aegilops sharonensis provided protection in the seedling stage to a wide range of pathotypes of the two diseases. Monosomic and telosomic analyses showed that the resistance genes occur on wheat chromosome 6A. This result could be confirmed making use of mapped chromosome 6A microsatellite markers. The introgressed chromatin appeared to involve the proximal part of 6AL and the complete 6AS arm and it was thus not possible to deduce the chromosome arm harbouring the resistance genes. The resistance showed non-Mendelian transmission. The genetic background of a heterozygote interacted with the introgressed region to result in either preferential or impaired female transmission. Male transmission appeared to be affected in a different way from female transmission and was exclusive in the genetic background studied. Symbols Lr56 and Yr38 are proposed to designate the respective genes of which line 0352-4 is the appropriate source material.