Francis Koekemoer

1. SENSAKO RUST
EVALUATION STRATEGY
Francois Koekemoer
South Africa

2. National breeding programs
• Sensako (private company ± 75% market share)
• Pannar (private company ±7% market share)
• Small Grain Institute – ARC-SGI (para-statal
company ± 18% market share)

3. National pre-breeding programs
• Free State University
• Stellenbosch University
• CenGen
• ARC-SGI

4. National monitoring program
• ARC-SGI

5. Wheat
Produc-on
Areas
- Irrigation areas
- Dryland Winter
wheat
- Dryland Spring
Wheat

7. TTKSF

10. PDRS
CCPS
MCDS

15. New wheat rust races in SA since 2000
2000: P. graminis f.sp. tritici TTKSF (2SA88) Ug99 race group
2005: P. graminis f.sp. tritici BPGSC (2SA105) Virulence for SrSatu in triticale
P. triticina (3SA144) Virulence for Lr32
P. striiformis f. sp. tritici 6E22A+ Virulence for YrA
2007: P. graminis f.sp. tritici TTKSP (2SA106) Ug99 race group, virulence for Sr24
2009: P. graminis f.sp. tritici PTKST (2SA107) Ug99 race group, virulence for Sr24+Sr31
P. triticina CCPS (3SA145) Virulence for Lr12+13+37
2010: P. graminis f.sp. tritici TTKSF+ Ug99 race group, virulence for SrWeb
P. triticina MCDS (3SA146) Virulence for Lr12+13+37
P. triticina FBPT (3SA147) Virulence for Lr12+13+37

16. Pre-breeding University of Stellenbosch
• MS-MARS
• Since 1998
• Specific genes via MAS
• APR
• Distribute rust resistance material
– Nurseries (8 editions since 2006)
– Lines together with molecular info
– Expanded to include replicated plots and 3m rows
– Supply data regarding CIMMYT nurseries

17. Introduction of new sources
• BC component
• Introduction of new sources of resistance
– T. dicoccoides: Lr53/Yr35 (6B)
– T. kotschyi: Lr54/Yr37 (2D)
– T. sharonense: Lr56/Yr38 (6A)
– T. peregrinum (UUSS): Lr59
– T. neglecta: Lr62/Yr42 (6A)
• Facilitated via MAS (and seedling tests)

18. Distribu1on
of
resistant
material
0
5
10
15
20
25
1
2
3
4
5
6
7
8
9
13
Gene
combina-ons
–
2012
Nursery

19. Evaluation and selection strategy
• Obtain sources for resistance
• CIMMYT, Europe, Australia, Argentina,
pre-breeding programmes
• Crosses in greenhouse
• Normally one backcross (BC1)
• Double haploids on F1 seeds

20. Evaluation and selection strategy
• Evaluate advance breeding lines and new DH
lines under field inoculated conditions and
conduct selections in early generation nurseries
– Stem and leaf rust
• Makhathini (artificially inoculated pathotypes) and
Napier (natural occurring pathotypes)
– Stripe rust
• Napier (artificially inoculated pathotypes)

21. Bethlehem
Johannesburg
Makathini
Napier

22. Breeding strategy
• Stem rust - Sr2 as pivot gene combined
with other genes
• Leaf Rust – Lr34 as pivot gene combined
with other genes
• Stripe rust – Yr18 as pivot gene combines
with other genes

23. Stem rust progress
suscep1ble
Sr2
intermediate
Sr2
+
?
genes
Sr2
+
?
genes

24. Successes and set backs
Cultivar Stem Rust Leaf Rust Stripe Rust
SST 88 S S MR
SST 015 S MS R
SST 027 MS MS R
SST 047 R R R
SST 056 MS MR MR
SST 087 S R R
SST 096 MR MR MR
SST 017 MR MR R
SST 0127 MR MR R
SST 0137 MR MR MR

25. Tools to expedite breeding
– Double haploids
– Shuttle breeding
– Marker assisted selection (cost?)

26. Interaction and stewardship
– Southern African Breeders Association (SAPBA)
– Winter Cereal Trust (WCT)
– Rust Workshop
– Try to avoid releasing single dominant genes
– Increase frequency of various genes in wheat
backgrounds

27. Acknowledgements
– BGRI
– Prof Zakkie Pretorius
– Dr Tarekegne Tarefe
– Mr Willem Botes
– Sensako team