Molecular charactarization of wheat advanced lines for leaf rust resistant genes using SSR markers

Area of Science:

• Plant genetics
• Crop science
• Agricultural biotechnology

Background:

• Wheat leaf rust, caused by Puccinia triticina, is a significant threat to global wheat production.
• Genetic resistance is crucial for managing wheat rust diseases and ensuring food security.
• Identifying and utilizing effective resistance genes is a key objective in wheat breeding.

Purpose of the Study:

• To screen wheat advanced lines for specific leaf rust resistance genes (Lr9, Lr13, Lr19, Lr24, Lr26, Lr28, Lr32, Lr34, Lr35, Lr36, Lr37, Lr39, Lr46).
• To assess the presence and frequency of these resistance genes in a collection of wheat germplasm.
• To evaluate the effectiveness of SSR markers in identifying leaf rust resistance genes.

Main Methods:

• Screening of fifty-seven wheat advanced lines.
• Utilizing thirteen SSR (Simple Sequence Repeat) markers to detect specific leaf rust resistance genes.
• Analyzing band patterns to confirm the linkage between SSR markers and resistance traits.

Main Results:

• Four SSR markers for Lr13, Lr32, Lr34, and Lr35 showed positive linkage with leaf rust resistance.
• Lr32 exhibited 100% frequency (57 lines), followed by Lr34 (89.4%, 51 lines), Lr35 (87.7%, 50 lines), and Lr13 (31.5%, 18 lines).
• Only 26% of the lines (15 lines) possessed all four identified resistance genes, indicating limited genetic diversity for these specific resistance traits.

Conclusions:

• The study identified specific leaf rust resistance genes (Lr13, Lr32, Lr34, Lr35) in wheat advanced lines using SSR markers.
• A limited number of variant genes for leaf rust resistance were detected in the studied population.
• Developing strategies to combine these genes for durable resistance and employing more effective markers for marker-assisted selection are recommended to combat wheat rust.