Amor Yahyaoui, Senior Cereal Pathologist, ICARDA Coordinator, ICARDA-CIMMYT Wheat Improvement Program Safiq Hakim, University of Aleppo, Syria Mogens Hovmoller AARHUS University (DIAS), Denmark

1. Pathotypic Evolution of Yellow (Stripe) rust in
CWANA (1998-2008).
Amor Yahyaoui,
Senior Cereal Pathologist, ICARDA
Coordinator, ICARDA-CIMMYT Wheat Improvement Program
Safiq Hakim,
University of Aleppo, Syria
Mogens Hovmoller
AARHUS University (DIAS), Denmark

2. Yellow (Stripe) Rust: Clear & Present Danger
The potential impact of wheat yellow (stripe) rust is
particularly serious in Central West Asia and East Africa
(CWANA) and could become a serious problem in North
Africa and even in Europe
Wheat Yellow (Stripe) Rust
Puccinia striiformis fsp tritici
(Pst)
Most common and widespread
rust disease of wheat
in CWANA
Stripe rust highly destructive but not well
understood disease. Pst could threaten food
security in many countries in CWANA

3. M.Hovmoller et al. , DIAS, DK

4. 2010 Yellow rust epidemic
In Syria: 20-70 % yield loss;
Iraq: >40% yield loss;
Turkey: >20% yield loss + 2-3 fungicide appl;
Important losses recorded in Algeria, Azerbaijan,
Ethiopia, Morocco, Uzbekistan, …

5. 2010 Yellow Rust Epidemic in Syria
Favourable
Climate Agro.Practice
(high seeding,
Fertilizer Rates)
Irrigation...
Susceptible mega.Variety.”Cham 8”
“New” Race-Vir Yr27 +
High Inoculum load

6. Where did the stripe rust (Pst) inoculum
came from?
Why was it so severe?
Epidemics caused by many changes:
Changes in cultivars-large areas grown to susceptible
varieties
Crop management
 Climate
 Change in pathotypes (new & virulent races)

7. Green Bridge & Rust Spore Migration
Factors attributed to the host, the pathogen, and the
environment affect the development of Pst rust
epidemics in CWANA
Trans-boundary pest
Changing World
Desert Locust vs. Rusts

8. ICWIP
Green Bridge
Gate for
West-East
rust spore
Movement
Green Bridge:
Wheat crop all Year
 Important overlap periods in East Africa, Yemen, CWA
What if no wheat in Yemen Nov-June?
Off season wheat cropping
Irrigated wheat (small areas +/- 20,000ha)
Regulated fungicide use

9. Green Bridge & Rust Spore Migration
A source of Pst inoculum is necessary to initiate an
epidemic;
Pst fungus must successfully over summer in the
area to provide a continuous supply of spores, or
goes through an alternate host;
Large quantities of spores
must blow in from another
area soon enough for an
epidemic to get an early
start.
D. Hodson-AGPP/FAO ; BGRI

10. Evolution/changes in Pst pathotypes (races)
in Syria
Year Country Pathotypes (Physiological races)
2001 Syria 6 E 16 6 E 36 38 E 150 70 E 130 230 E 150
2002 Syria 0 E 16 2 E 18 102 E 150 238 E 134 166 E 158
2002 Syria 166 E 150 230 E 150 238 E 150 119E60
2003 Syria 0E0 0E2 0E8 2E0 0 E 16
2003 Syria 0 E 18 32 E 0 0 E 28 4 E 12 12 E 6
2003 Syria 4 E 16 46 E 46 65 E 6 15 E 166 14 E 134
2003 Syria 14 E 190 247 E 16 32 E 130 78 E 130 255 E 112
2003 Syria 128 E 148 199 E 132 134 E 134 230 E 222 175 E 150
2004 Syria 206 E 22 84 E 2 68 E 98
2006 Syria 4E0 10 E 32 182 E 16 191 E 163
2007 Syria 0E0 3E0 0E3 4E0 32 E 0
2007 Syria 98 E 3 64 E 49 103 E 5 140 E 5 32 E 135
2007 Syria 79 E 124 229 E 26 111 E 215 64 E 159 189 E 48
2007 Syria 101 E 128 129 E 52 54 E 248 204E 76
Highly Effective YRG: (5); (15); (3b,4b); (SP)
Effective YRG: (CV); (10); (1)

11. Evolution/changes in Pst pathotypes (races)
in Lebanon and Yemen,
Yea Country Pathotypes (Physiological races )
2002 Lebanon 238 E 134 166 E 158 238 E 190 0E8
2003 Lebanon 0 E 14 31 E 150 173 E 206 166E158
2005 Lebanon 204 E 76
Yr*: SO, “3b,4b”, CV, 5, 15, SP
2001 Yemen 230 E 12 4 E 40 38 E 4 119 E 60
2005 Yemen 22 E 245 137 E 158 128 E 143 0 E 128 4 E 190
2001 Iraq 230 E 44
2007 Tunisia 38 E 18
Yr*: Effective Resistance Genes

12. Common Virulence patterns
M.Hovmoller et al. , ARHUS, DK

13. Effective/ineffective Resistance Genes: Avocet-Isogenic Lines
Virulent Avirulent Race
6,7,8,9,11,12,17,18,27,A / 1,5,10,15,SP 422 E 158
6,7,8,9,11,18,27,A / 1,5,10,12,15,17,SP 7 E 150
7,8,9,11,18,27,A / 1,5,6,10,12,15,17,SP 7 E 150
6,7,8,9,12,17,18,27,A / 1,5,10,11,SP 110 E 182
6,7,8,9,11,12,17,18,A / 1,5,10,15,SP,27 129 E 52
1,6,8,9,10,11,15,17,18,27,A / 5,7,12,SP 101 E 128
Virulent Avirulent Race
6,7,8,9,10,11,17,18,27,A / 1,5,12,15,SP 22 E 245
6,7,8,9,11,12,17,18,27,A / 1,5,10,15,SP 137 E 158
6,7,8,9,11,12,17,18,27,A / 1,5,10,SP,27 128 E 143
6,7,8,9,11,12,17,18,27,A / 1,5,10,15,SP 4 E 190

14. Effective Yellow Rust Resistance Genes
Yr-RG
Important resistance genes widely used in breeding
programs have lost their effectiveness (Yr1, Yr 6,
Yr7, Yr9, Yr17, Yr18, Yr27)
Other are breaking down in parts of the region
(Yr15, Yr10, …)
Few Yr. RG still effective in CWANA
Yr 5, Yr “3b,4a” (Hybrid 46) , Yr Sp

15. Effectiveness of Yr-RG at seedling and adult growth stages
Seedling Gr.Stg Adult Gr. Stg
Genotypes R-Genes
R S %R %S R S %R %S
Yr 5/ 6* Avocet S 5 63 0 100 0.0 108 5 96 4
Hybrid 46 3b,4b 63 0 100 0.0 84 5 94 6
Yr Sp / 6* Avocet S SP 63 0 100 0.0 91 7 93 7

16. Effectiveness of Yr-RG at seedling and adult growth stages
R- Seedling Gr.Stg Adult Gr.Stg
Genotypes Genes R S %R %S R S %R %S
Yr 15/ 6* Avocet S 15 62 1 98.4 1.6 82 7 92 8
Cham 1 DW 63 0 100 0.0 72 6 92 8
Yr1/ 6*Avocet S 1 61 2 96.8 3.2 59 24 71 29
Yr 10/6* AvocetS 10 58 5 92.1 7.9 49 29 63 37
Yr Sp/6* AvocetS SP 63 0 100 0.0 91 7 93 7

17. Effectiveness of Yr-RG at seedling and adult growth stages
Seedling Gr.Stg Adult Gr.Stg
Genotypes R-
Genes R S %R %S R S %R %S
Reichersberg 42 7+ 29 34 46.0 54.0 57 9 86 14
Vilmorin 23 3a,4a+ 48 15 76.2 23.8 25 0 100 0
Nord Despres 3a,4a 47 16 74.6 25.4 24 1 96 4
Yr 8/ 6* Avocet S 8 22 41 34.9 65.1 40 23 63 37
Carstens V CV 52 11 82.5 17.5 97 2 98 2

18. Effectiveness of Yr-RG at seedling and adult growth stages
Seedling Stage Adult Stage
R-
Genotypes Genes R S %R %S R S %R %S
Yr 18/ 3* Avocet S 18 28 35 44.4 55.6 9 60 13 87
Jupateco R 18+ 23 40 36.5 63.5 25 44 36 64
YrSk / 3* Avocet S 27 50 13 79.4 20.6 12 41 23 77
Yr 17/ 4* Avocet S 17 34 29 53.9 46.1 25 36 41 59

19. Recent Defeated Resistance Genes
Broad spectrum Pst races
Defeated Gene
Year Combinations Races
2003 Yr9, Yr27 199 E 132
Yr18
2006 137 E 158
2007 101 E 128
Defeated Gene
Year Combinations Races
2003 31 E 150
2004 Yr8, Yr18 110 E 182
2005 Yr9, Yr27 54 E 248
2006 22 E 245 4 E 190 128 E 248

20. Defeated Yr10 across the region
Pst. Virulent on durum wheat
Defeated Yr 10 Gene Races
Year (location)
2003 Syria 255E112 247E16
2003 Lebanon 31E150
Pst. Isolates virulent on
2005 Yemen, Azerbaijan durum wheat (seedling
growth stage)
2006 Syria 191E163
2007 Syria 189E48

21. Under favourable weather conditions;
Potential of wheat yellow rust epidemics
from new emerging virulent rust (Pst) races
Remains a real threat to the wheat
producing countries

22. Wheat
Partnerships & Communications
Wheat
Regional Yellow rust Conferences
Iran 2001: SPII & R.Johnson (>200 P) $ Iran, ICARDA, CIMMYT”
Pakistan 2004; PARK & O.Abdalla (>150 P) $ ACIAR, DANIDA, ICARDA, CIMMYT
Uzbekistan 2006: PFU & S.Rajaram (> 80 P) $ ACIAR, DANIDA, ICARDA
Turkey 2009: TAGEM & O.Mamluk (> 100 P) $ FAO, AFESD, ICARDA, CIMMYT
Syria 2013: ICARDA &….

23. Acknowledgment
NARS Collaborators:
Rust Networks Donors
NVRS: Egypt, Ethiopia, Sudan & Yemen, Eritrea IFAD (NVRS)
West Asia: Turkey, Iran, Syria, Lebanon, Pakistan DANIDA (IDM)
ACIAR
Central Asia & Caucasus: Azerbaijan, Georgia,
AFESD (Rust Mgt)
Kazakhstan, Kyrgyzstan, Tajikistan
FAO (LoA’s)
North Africa: Algeria, Morocco, Tunisia
Advanced Research Institutions & Universities
DIAS, & KVL-Denmark
PBI, Australia Contributors
WSU, MSU- USA
Univ. Aleppo & Damascus, Syria
ICARDA
Research Support CIMMYT
ICARDA-Maha,Munzer, Shafiq SPII
DIAS: Ellen, AnneMarie-DK DIAS, Flak
SPII: Torabi et al- Iran
CREFCI; Lutfi et al..- Turkey
EIAR: Ayele et al--Ethiopia
ARC: Sherif et al---Egypt
IAV: Ezzahiri et al-- Morocco

24. Thank You