1 / 24

Suppression of rust resistance in wheat

Suppression of rust resistance in wheat. Mina Talajoor Department of Plant Sciences & Plant Pathology Montana State University. Origins of Wheat. Triticum turgidum (2n=4x, AABB) . Triticum urartu (2n=2x, AA). Triticum aestivum (2n=6x, AABBDD). Aegilops tauschii (2n=2x, DD).

geordi
Télécharger la présentation

Suppression of rust resistance in wheat

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Suppression of rust resistance in wheat Mina Talajoor Department of Plant Sciences & Plant Pathology Montana State University

  2. Origins of Wheat Triticum turgidum (2n=4x, AABB) Triticumurartu (2n=2x, AA) Triticum aestivum (2n=6x, AABBDD) Aegilopstauschii (2n=2x, DD) Aegilopsspeltoides (2n=2x, SS) Photos courtesy of Li Huang

  3. Wheat Rust Obligate biotrophic fungus • Leaf Rust Pucciniatriticina

  4. Wheat Rust Obligate biotrophic fungus • Leaf Rust • Stem Rust • Leaf Rust • Stem Rust Pucciniatriticina Pucciniagraminisf. sp. tritici Photo courtesy of NCERA-184 & WERA-97

  5. Wheat Rust Obligate biotrophic fungus • Leaf Rust • Stem Rust • Stripe Rust Pucciniatriticina Pucciniagraminisf. sp. tritici Pucciniastriiformisf. sp. tritici Photo courtesy of NCERA-184 & WERA-97

  6. Breeding for Resistance • R-gene nomenclature • Leaf Rust: Lr • Stem Rust: Sr • Stripe (Yellow) Rust: Yr • R-genes confer resistance in a race-specific manner Lr21 Confers resistance to leaf rust race PRTUS6

  7. Suppression of stem rust resistance A B D • Stem rust-specific suppressor on Canthatch 7DL 1 Sr9 Sr16 2 3 Sr12 Sr7 4 7DL 5 Su 6 7

  8. Objective Investigate the specificity of the Canthatch suppressor Is it stem rust-specific? Is suppression related to genomes or chromosome locations?

  9. Objective • Investigate the stem rust specificity of the suppressor • Genetic characteristic of the suppressor • Absence of leaf rust or stripe rust resistance genes in the Canthatch background

  10. Approach

  11. Objective • Identify patterns of suppression related to genomes or chromosome locations

  12. Approach Genome Chromosome

  13. Control Crosses • Other suppressors in D genome (Bai & Knott, 1991) • Suppression may or may not be from our suppressor • Cross with mNS1-Can • If resistance is suppressed, it is not because of our suppressor • If resistance is expressed, it supports our hypothesis that it is because of our suppressor.

  14. Quantifying Infection Type Resis. Susc. Roelfs, A. & Singh, R. Rust diseases of wheat: Concepts and methods of disease management. 81 (Agribookstore/Winrock: 1992).

  15. Sample analysis

  16. SrX Canthatch x susuSrXSrX Su Su srxsrx All Resistant Su does not suppress SrX Screen F1 plants with race avirulent to SrX F1 plants: All Susceptible Su might suppress SrX Su suSrXsrx

  17. SrX mNS1-Can x susuSrXSrX sususrxsrx All Resistant There is no other gene suppressing expression of SrX in this background Screen F1 plants with race avirulent to SrX F1 plants: All Susceptible There is another suppressor in the background that suppresses SrX susuSrXsrx

  18. Statistical Analysis • Test 20 seeds • A significant difference 1/20 = 0.05 • Should be all resistant or all susceptible

  19. Crossing Log

  20. Sample Infection Type (IT) Data

  21. Alpowa SrX x Su SuSrXSrX sususrxsrx F1 plants: resistant SusuSrXsrx

  22. F1 plants: resistant Su suSrXsrx 9 : 3 : 3 : 1 F2 plants: Su__ SrX__ Su __ srxsrx susuSrX__ sususrxsrx ? resistant susceptible susceptible

  23. F1 plants: resistant Su suSrXsrx 9 : 3 : 3 : 1 F2 plants: Su__ SrX__ Su __ srxsrx susuSrX__ sususrxsrx resistant susceptible susceptible susceptible resistant 9 : 7 Alpowa suppressor suppresses SrX resistant : susceptible 3 : 1 Alpowa suppressor does not suppress SrX

More Related