Presentation is loading. Please wait.

Presentation is loading. Please wait.

SUPPRESSION OF RUST RESISTANCE IN WHEAT Mina Talajoor Department of Plant Sciences & Plant Pathology Montana State University.

Similar presentations


Presentation on theme: "SUPPRESSION OF RUST RESISTANCE IN WHEAT Mina Talajoor Department of Plant Sciences & Plant Pathology Montana State University."— Presentation transcript:

1 SUPPRESSION OF RUST RESISTANCE IN WHEAT Mina Talajoor Department of Plant Sciences & Plant Pathology Montana State University

2 Triticum turgidum (2n=4x, AABB) Origins of Wheat Triticum aestivum (2n=6x, AABBDD) Aegilops tauschii (2n=2x, DD) Triticum urartu (2n=2x, AA) Aegilops speltoides (2n=2x, SS) Photos courtesy of Li Huang

3 Wheat Rust Leaf Rust Puccinia triticina Obligate biotrophic fungus

4 Wheat Rust Leaf Rust Stem Rust Leaf Rust Stem Rust Puccinia triticina Puccinia graminis f. sp. tritici Photo courtesy of NCERA-184 & WERA-97 Obligate biotrophic fungus

5 Wheat Rust Leaf Rust Stem Rust Stripe Rust Puccinia triticina Puccinia graminis f. sp. tritici Puccinia striiformis f. sp. tritici Photo courtesy of NCERA-184 & WERA-97 Obligate biotrophic fungus

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 Stem rust-specific suppressor on Canthatch 7DL 7DL ABD Su Sr7 Sr9 Sr16 Sr12

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 LocationLrYrSr 4ASr7b 2BLr16Yr5Sr36 3B

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

12 Approach ABD 1 Sr31 Lr26 Sr18 Lr21 2 Sr34 Lr11 Sr21 Lr17 Yr8 Sr9g Sr36 Sr16 Yr5 Lr16 Sr6 3 Sr27Sr12 Sr24 Lr24 4 Sr7a Sr7b 5 Lr52 Yr47 Sr30 6 Sr8Lr9Sr5 7 Sr22 Lr47 Sr17 Yr2 Yr6 Lr34 Yr18 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 Roelfs, A. & Singh, R. Rust diseases of wheat: Concepts and methods of disease management. 81 (Agribookstore/Winrock: 1992). Resis.Susc.

15 SAMPLE ANALYSIS

16 Canthatch Su Su srx srx Su might suppress SrX Su does not suppress SrX All Resistant All Susceptible SrX x su su SrX SrX Su su SrX srx F 1 plants: Screen F 1 plants with race avirulent to SrX

17 mNS1 -Can su su srx srx There is another suppressor in the background that suppresses SrX There is no other gene suppressing expression of SrX in this background All Resistant All Susceptible SrX x su su SrX SrX su su SrX srx F 1 plants: Screen F 1 plants with race avirulent to SrX

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

22 su su srx srx x Su Su SrX SrX resistant Alpowa SrX Su su SrX srx F 1 plants:

23 Su __ SrX __ su su SrX __ Su __ srx srx su su srx srx F 2 plants: 3913::: resistantsusceptible ? resistant Su su SrX srx

24 Su __ SrX __ su su SrX __ Su __ srx srx su su srx srx F 2 plants: 3913::: resistantsusceptible resistant Su su SrX srx F 1 plants: 3 : 1Alpowa suppressor does not suppress SrX resistant resistant : susceptible 9 : 7Alpowa suppressor suppresses SrX


Download ppt "SUPPRESSION OF RUST RESISTANCE IN WHEAT Mina Talajoor Department of Plant Sciences & Plant Pathology Montana State University."

Similar presentations


Ads by Google