Differential sets are a vital component of race analysis. The aim is to have a set of differential varieties, ideally each with a different single resistance gene, which can distinguish races by their qualitative differences in reactions to different pathogen strains. Numerous different differential sets are in use by rust labs undertaking race analysis on a routine basis.
This current lack of consistency in differential sets between rust labs makes international comparison of results extremely difficult. As a result of the recognition of the emerging threat posed by new races of stem rust like Ug99 and the clear need for global collaboration and consistency, a new international set of differentials has been agreed upon by a panel of global rust experts. Partners in the BGRI are now using the following international core set of differentials to ensure global consistency for race analysis. Optional additions to the international core set can be made by individual labs to cover local needs.
For more information about obtaining seed of the International core diferential set. Please contact:
Dr. K. Nazari, ICARDA, P.O. Box 5466, Aleppo, Syrian Arab Republic. Email: [email protected]
Dr. T. Fetch, AAFC, Cereal Research Centre, 195 Dafoe Road, Winnipeg, Canada R3T 2M9. Email: [email protected]
BGRI International Core Differential Set – Stem Rust (ordered by sets used in North American nomenclature system)
Set | Gene | LIT | Diff line for world distribution, April 2009 | Origin/Pedigree | Source |
1 | Sr5 | 0 | ISr5-Ra CI 14159 | Thatcher/Chinese Spring | Jin, USDA |
| Sr21 | 1- | T monococcum/8*LMPG-6 DK13 | Einkorn CI 2433 | Fetch, AAFC |
| Sr9e | 1- to 2- | Vernstein PI 442914 | Little Club //3* Gabo /2* Charter /3/3* Steinwedel / CI 7778 | Jin, USDA |
| Sr7b | 2 | ISr7b-Ra CI 14165 | Hope/Chinese Spring | Jin, USDA |
2 | Sr11 | ; to 2- | Yalta PI 155433 | Kenya C6402/Pusa4//Dundee | Park, Australia |
| Sr6 | 0; | ISr6-Ra CI 14163 | Red Egyptian/Chinese Spring | Jin, USDA |
| Sr8a | 2- to 2 | Mentana W1124 PI 221154 | Rieti / Wilhelmina // Akagomughi | Park, Australia |
| Sr9g | 2- | Acme CI 5284 | Selection from Kubanka (CI 1516) | Pretorius, SA |
3 | Sr36 | 0; | W2691SrTt-1 CI 17385 | CI 12632 T. timopheevii | Jin, USDA |
| Sr9b | 2 | Prelude*4/2/Marquis*6/Kenya 117A | Kenya 117A | Fetch, AAFC |
| Sr30 | 1+ to 2 | Festiguay W2706 PI 330957 | Festival / Uruguay C10837 | Park, Australia |
| Sr17 | ;1 | Prelude/8*Marquis*2/2/Esp 518/9 | Esp 518/9 | Fetch, AAFC |
4 | Sr9a | 1- to 2- | ISr9a-Ra CI 14169 | Red Egyptian/Chinese Spring | Jin, USDA |
| Sr9d | 1- to 1 | ISr9d-Ra CI 14177 | Hope/Chinese Spring | Jin, USDA |
| Sr10 | ;1N to 3C | W2691Sr10 CI 17388 | Marquis*4/Egypt NA95/2/2*W2691 | Jin, USDA |
| SrTmp | 2- | CnsSrTmp | Triumph 64 (CI 13679)/Chinese Spring | Jin, USDA |
5 | Sr24 | 1- to 2- | LcSr24Ag | Little Club/Agent (CI 13523) | Jin, USDA |
| Sr31 | 1- to 2 | Kavkaz/Federation4 | Kavkaz | Pretorius, SA |
| Sr38 | X= | Trident | Spear*4/VPM (PI 519303) | Park, Australia |
| SrMcN | 2- | McNair 701 (CI 15288) | | Jin, USDA |
Source: Prof. Z.A. Pretorius, University of the Free State, South Africa
