Postulation and Efficiency of Leaf Rust Resistance Genes of Wheat and Biological Control of Virulence Formulae of Puccinia triticina Races

Rust-infected wheat leaves caused by Puccinia triticina Eriks. were collected throughout the survey of nurseries at Tag El-Ezz Agricultural Research Station, Dakahlia Governorate, Egypt, in order to evaluate and test the efficiency of leaf rust resistance genes and then determine suitable biological control agents for such pathogen. Seven formulae of P. triticina were derived by single uredinial isolates. The TKTT pathotype was the most virulent formula. KKTT and PKTT pathotypes showed the most common frequencies (23.08 % each). The leaf rust resistance gene (Lr9) was the most efficacy one. Postulation of rust genes in the commercial cultivars proposed that Giza 168 and Sakha 93 probably did not contain any common genes. Sakha 93 probably exhibited 6 resistance genes (1, 2c, 3, 26, 3ka and 30). Biological control of such rust showed that combined application of arbuscular mycorrhizal fungi and Azospirillum amazonense improved wheat plant growth, yield and quality, in addition to the reduction in rust disease severity, compared with untreated ones.