Identification of Isozyme and Molecular Markers Linked to Leaf Rust Resistance in New Egyptian Wheat Lines

Leaf rust is a crucial disease of wheat (Triticum aestivium L.) in Egypt and worldwide. It causes by fungi Puccinia triticina. Leaf rust could be controlled by genetic resistance to limit yield damages. In this study, we evaluate new wheat lines for resistance to leaf rust disease. In addition, determine the activities of polyphenol oxidase and peroxidase in leaf rust resistance wheat lines compared with the healthy control. Also, we identify Inter-simple sequence repeat (ISSR-PCR) markers linked to Lr resistant genes at the seedling stage. All wheat lines were resistant to leaf rust at seedling stage. However, under the field conditions three lines No. 3, 7 and 8 were resistant, while other seven were susceptible. Consequently, it could be concluded that lines No. 3, 7 and 8 were resistant to leaf rust in both stages. Eight anchored ISSR primers were screened to identify polymorphic bands between the leaf rust resistance and control wheat plants. A total of 104 scorable fragments were amplified of which 54 monomorphic and 46 bands were polymorphic resulting in a polymorphism of 44.23%. The largest number of ISSR-PCR specific markers scored in leaf rust resistance wheat line No. 10 (three markers), followed by leaf rust resistance wheat lines No. 2, 3, 4 and 8 (two). The lowest number of specific bands existed in resistance line No. 1 (one unique marker). These markers could be applied in wheat breeding programs, as marker assisted selection. By a backcross program was achieved by recurrent parents between the susceptible high-quality wheat and the resistant gene carrying ones as donor parents