Sensako Rust Evaluation Strategy

SENSAKO RUST EVALUATION STRATEGY

Francois Koekemoer South Africa

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)

National pre-breeding programs

•  Free State University •  Stellenbosch University •  CenGen •  ARC-SGI

National monitoring program

•  ARC-SGI

Wheat  Produc-on  Areas  

- Irrigation areas

- Dryland Winter wheat - Dryland Spring Wheat

TTKSF  

PDRS   CCPS  

MCDS  

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

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

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)

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    

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

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)

Bethlehem  

Johannesburg  

Makathini  

Napier  

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

Stem rust progress

suscep1ble   Sr2  intermediate   Sr2  +  ?  genes   Sr2  +  ?  genes  

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

Tools to expedite breeding

–  Double haploids

–  Shuttle breeding

–  Marker assisted selection (cost?)

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

Acknowledgements

–  BGRI

–  Prof Zakkie Pretorius

–  Dr Tarekegne Tarefe

–  Mr Willem Botes

–  Sensako team