Molecular Markers and Postulation Study of Leaf Rust Resistance Genes in Various Egyptian Wheat Cultivars

The current investigation was carried out at seedling stage under greenhouse condition to: (1) postulate leaf rust resistance genes in ten Egyptian spring wheat cultivars at seedling stage and (2) Verify the presence of resistance genes in the selected cultivars using specific molecular markers linked to leaf rust resistance genes. The ten Egyptian spring wheat cultivars i.e. Misr 1, Misr 2, Sids 12, Sids 13, Gemmeiza 9, Gemmeiza 10, Gemmeiza 11, Sakha 93, Sakha 94 and Giza 168 as well as eight monogenic lines carrying single gene for leaf rust resistance i.e. Lr 21, Lr 25, Lr 32, Lr 35, Lr 37, Lr 39, Lr 47, and Lr 51 were tested at seedling stage using 15 leaf rust pathotypes i.e. BDGGK, CPPTB, DMKRT, FKRNK, FTFNB, KTSQG, LDDLD, LFGLL, NRRLS, NTTSR, PTKLN, STRTQ, TJKPR, TQTMJ and TTJBC. Eight specific molecular markers were known to be linked with the Lr,s resistance genes, i.e. Lr 21, Lr 25, Lr 32, Lr 35, Lr 37, Lr 39, Lr 47, and Lr 51 were used to verify the presence of these genes in the tested Egyptian wheat cultivars. The postulation test theorized the presence of Lr 25, Lr 32, Lr 35, Lr 37 and Lr 47 in Sids 12. Moreover, the wheat cultivar Misr 1 may have four genes i.e. Lr 25, Lr 35, Lr 39 and Lr 51. The wheat cultivars Misr 2, Sids 13, Sakha 94 and Giza 168 may have two genes i.e. Lr 35 and Lr 39 in the wheat cultivar Misr 2 and the same two genes Lr 35 and Lr 37 in the three wheat cultivars Sids 13, Sakha 94 and Giza 168. On the other hand, the wheat cultivars Gemmeiza 9 and Sakha 93 may have only one gene i.e. Lr 35 and Lr 32, respectively. While, the wheat cultivars Gemmeiza 10 and Gemmeiza 11 did not have any of the tested Lr genes under study using the fifteen tested pathotypes of P. triticina but it may be carrying some other genes. In the same way, all of the tested wheat genotypes may also carries additional resistant gene (s).The molecular markers survey with specific markers revealed that, the specific markers for Lr 21 and Lr 47 were detected in all tested cultivars. The marker for Lr 32 was recognized in four cultivars i.e. Gemmeiza10, Sakha 93 Sakha 94 and Giza168. The marker for Lr 39 was identified in all cultivars except Sakha 94. The markers for Lr 25, Lr 35, Lr 37 and Lr 51 were not found in any the tested cultivars. This study may add valuable information about resistance genes in the Egyptian wheat cultivars which may be used in pyramiding more genes in each cultivar or used as donor parents in different wheat genetic improving programs.