AFLP Molecular Markers For Leaf Rust Resistance Gene Lr38 In Wheat

The leaf rust resistance gene Ir38 in wheat was isolated from an Agropyron intermedium group 7 chromosome. It was mapped on 6DL of chromosome. Lr38 confer strong leaf rust resistace. No virulent puccinia recondita strain was found to Lr38 in the world untill now. The complete linkage or tightly linkage markers of Lr38 will be more important to isolating and using resistant gene Lr38.Amplified fragments length polymorphism (AFLP) analysis was carried out in Thatcher, near-isogenic lines carrying fifteen different genes conferring resistance against leaf rust and F2 progency of ThLr38 X Thather. The main results were as follows:Most of the 210 pairs primers screened for AFLP analysis gave clear amplification products. Sixty-three of them amplified polymorphic bands in Thatcher and 15 wheat leaf rust resistance NILs with 30 percent of polymorphism. Analysis 127 of F2 progeny of ThLr38 Thather using sixty-three primers was taken and two markers were identified with MAPMAKER 3.0 sofeware that tightly linked to Lr38 resistance trait and one marker linked to Lr38 susceptible trait, then were named as: P-AGC M-CAG193 (0.80 cM) , P-ACG/M-CTG355 (0.80cM) , P-AGC M-CAG230 (4.80cM) , respectively. The research made this leaf rust resistance gene had more potential in marker-assisted breeding program in wheat. It also provides a step stone for mapping genetic map, physical map and the eventual cloning. The study show that fix solution can use 3 to 4 times in stain procedure, and staining solution and developing solution can use again when the period of two stains intervene between 20 and 30 miniutes. This made the stain not only true but also economical.