Effect of cytoplasm on expression of genes for resistance to Puccinia triticina

The F2 progenies from crosses of wheat varieties Pliska, Sreća, Vila, Holly, three BM lines as Lr 26, Lr 34 and Lr 38 near isogenic lines (NIL), were tested simultaneously in the greenhouse at seedling stage (20°C) and differentiated according to the reaction type to Puccinia triticina monopustule isolate collected from Pesma, the most resistant wide grown variety in Serbia. The presence of Lr 26 and Lr 26 + Lr 34 genes was found in incomplete but not in partially resistant varieties Sreća and Vila. Pliska and three BM lines had a complete resistance controlled by other genes. Genes from Pliska acted complementary in authentic cytoplasm and were single effective in Lr 34 NIL (Thatcher background) one. Resistance of two BM lines was dependent of one gene. Lr 26 and Lr 34 had influence on resistance enhancement in the F2 of crosses with Sreća and Vila when NILs were donors of cytoplasm. They also increased frequency of completely resistant plants in progenies of Pliska. Resistance suppression controlled by gene linked with Lr 34 on 7D chromosome was evident