Molecular Diversity of 23 Wheat Leaf Rust Resistance Near-Isogenic Lines Determined by Sequence-Related Amplified Polymorphism

【Objective】The research analysed the genetic diversity of wheat leaf rust resistance near-isogenic lines in Thatcher background and investigated the feasibility of SRAP marker applied in study of wheat leaf rust resistance genes marker and clone. 【Method】SRAP (sequence-related amplified polymorphism) technique was used in analysis of twenty-three wheat leaf rust resistance near-isogenic lines and Thatcher. 【Result】Forty-one of 128 SRAP primer combinations identified from a total of 537 reproducible fragments. Among them, 49.5% were polymorphic, and 115 of them were specific bands (10.6%). Six to 41 fragments were amplified per primer combination, with an average of 13.1 bands. The number of polymorphic fragments for each primer combination varied from 1 to 13, with an average of 2.8. A cluster analysis was performed using NTSYSpc Version 2.10e. Cluster analysis revealed twenty three wheat leaf rust resistance near-isogenic lines and Thatcher into two clusters of A and B with the similarity coefficient of 0.72. 96% of them were clustered into cluster B, which was divided into group Ⅰand groupⅡ. 95% of the near isogenic lines in cluster B fell into group Ⅱ. Group Ⅱ included four small groups with 0.785 similarity coefficient. 【Conclusion】It is concluded that the twenty-three wheat leaf rust resistance near-isogenic lines are different at molecular level. All these results showed SRAP marker is simple, economic and effective, and it could be used in study of wheat leaf rust resistance genes.