Sensako Rust Evaluation Strategy
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Transcript of Sensako Rust Evaluation Strategy
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)
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)
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
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
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