1. Australian Cereal Rust Control Program Consultative Committee September 27th Fulbright Scholarship, Exotic rust threats
Australian
Cereal
Rust
Control
Program
Robert Park
GRDC Chair of Cereal Rust Research

2. Pathogenic variability in wheat rusts in Australia - 11 exotic incursions since 1915
Pathotype
Year
Likely origin
1. Stem rust
126-5,6,7,11
1925 ?
2. Stem rust
21-0
1954
Central Africa?
3. Stem rust
326-1,2,3,5,6
1969
Central Africa
4. Stem rust
194-1,2,3,5,6
5. Stripe rust
104 E137 A-
1979
France
6. Leaf rust
53-1,(6),(7),10,11
1981
7. Leaf rust
104-2,3,(6),(7),11
1984
8. Leaf rust
76-1,3,5,10,12
1996
9. Stripe rust
134 E16 A+
2002
North America?
10. Leaf rust
11. Leaf rust
10-1,3,9,10,12
76-3,5,9,10 +Lr37
2004

3. Pathogenic variability in wheat rusts in Australia - 11 exotic incursions since 1915
Pathotype
Year
Likely origin
1. Stem rust
126-5,6,7,11
1925 ?
2. Stem rust
21-0
1954
Central Africa?
3. Stem rust
326-1,2,3,5,6
1969
Central Africa
4. Stem rust
194-1,2,3,5,6
5. Stripe rust
104 E137 A-
1979
France
6. Leaf rust
53-1,(6),(7),10,11
1981
7. Leaf rust
104-2,3,(6),(7),11
1984
8. Leaf rust
76-1,3,5,10,12
1996
9. Stripe rust
134 E16 A+
2002
North America?
10. Leaf rust
11. Leaf rust
10-1,3,9,10,12
76-3,5,9,10 +Lr37
2004

4. Pathogenic variability in wheat rusts in Australia - 11 exotic incursions since 1915
The frequency of exotic incursions is increasing:
Number of incursions
Year

5. Intercontinental tracking of rust pathogens
-modelling wind trajectories, Dr Dave Hodson FAO [UN]
“Rustmapper”
10 day prediction, November 4th
In 1969, two stem rust races transported by high altitude winds to Australia from Central Africa

6. SSR fingerprinting of stem rust isolates from Pakistan, March 2009
Tracking wheat rust pathogens - microsatellite (SSR) markers
- 80+ SSRs now available for stem rust (Puccinia graminis)
- are being used to assess global diversity in P. graminis using historical collections
- are also being used in diagnostics e.g. stem rust in Pakistan in 2009:
ssr 16
Ug99
Pakistan 09 1 2 3
Australia
ssr 13
Ug99
Pakistan 09 1 2 3
Australia
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given) 1
ex Local White 2
ex Attila 7 3
ex Seri 82
SSR fingerprinting of stem rust isolates from Pakistan, March 2009 1 2 3

7. Fulbright Scholarship Program
Established in 1946 by Senator J. William Fulbright and US Government in cooperation with foreign governments
Aim - to promote mutual understanding through international education & cultural exchange
Australian-American Fulbright Commission established in 1949
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

8. Fulbright Scholarship Program
Established in 1946 by Senator J. William Fulbright and US Government in cooperation with foreign governments
Aim - to promote mutual understanding through international education & cultural exchange
Australian-American Fulbright Commission established in 1949
Fulbright Senior Scholarships - available to Australians who are:
Scholars of established reputation working in an academic institution who intend to teach or undertake research.
Practising professionals who have established reputations in their fields.
Senior members of academically-based professions who are currently engaged in the private practice of their profession.
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

9. Fulbright Scholarship Program
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

10. USDA Cereal Disease Laboratory (formerly Cereal Rust Laboratory)
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)
USDA Cereal Disease Laboratory (formerly Cereal Rust Laboratory)
University of Minnesota
St Paul
Minnesota

11. Australian summer vs. U.S (mid west) winter?
08 January 2011
21 January 2011
[coldest day in 2 years, min temp -260C]
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

12. University of Minnesota
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)
University of Minnesota
St Paul
Minnesota

13. Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

14. 14

15. Park rust work at USDA CDL
- Seedling tests of Australian wheats and barleys and other germpasm to:
- Stem rust pathotypes:
TTKSK, TTKST, TTTSK [Ug99 and variants]
TRTTF, JRCQC [durum virulent, Sr9e and Sr13]
TTTT, 15B [North American]
- Leaf rust pathotypes [incl. two that are more virulent on durum]
- Seedling tests of Australian oats and other germplasm to:
- US pathotypes of crown rust [incl. Pc91 virulent pathotype]
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

16. Stem rust pathotype nomenclature North American system
Differential
Code 1 2 3 4 B L C H D F G J K M N P Q R S T
Set 1
Sr5, Sr21, Sr9e, Sr7b
Set 2
Sr11, Sr6, Sr8a, Sr9g
Set 3
Sr36, Sr9b, Sr30, Sr17
Set 4
Sr9a, Sr9d, Sr10, SrTmp
Set 5
Sr24, Sr31, Sr38, SrMcN

17. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S H
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
;2- [Low]
4 [High]

18. Stem rust pathotype nomenclature North American system
Differential
Code 1 2 3 4 B L C H D F G J K M N P Q R S T
Set 1
Sr5, Sr21, Sr9e, Sr7b
Set 2
Sr11, Sr6, Sr8a, Sr9g
Set 3
Sr36, Sr9b, Sr30, Sr17
Set 4
Sr9a, Sr9d, Sr10, SrTmp
Set 5
Sr24, Sr31, Sr38, SrMcN

19. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S H
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
;2- [Low]
4 [High]

20. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S H
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
;2- [Low]
4 [High]

21. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S H
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
;2- [Low]
4 [High]

22. Stem rust pathotype nomenclature North American system
Differential
Code 1 2 3 4 B L C H D F G J K M N P Q R S T
Set 1
Sr5, Sr21, Sr9e, Sr7b
Set 2
Sr11, Sr6, Sr8a, Sr9g
Set 3
Sr36, Sr9b, Sr30, Sr17
Set 4
Sr9a, Sr9d, Sr10, SrTmp
Set 5
Sr24, Sr31, Sr38, SrMcN

23. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S H
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
;2- [Low]
4 [High]

24. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S H
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
;2- [Low]
4 [High]

25. Stem rust pathotype nomenclature North American system
Differential
Code 1 2 3 4 B L C H D F G J K M N P Q R S T
Set 1
Sr5, Sr21, Sr9e, Sr7b
Set 2
Sr11, Sr6, Sr8a, Sr9g
Set 3
Sr36, Sr9b, Sr30, Sr17
Set 4
Sr9a, Sr9d, Sr10, SrTmp
Set 5
Sr24, Sr31, Sr38, SrMcN

26. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S H
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
;2- [Low]
4 [High]

27. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
3+ [High]
4 [High]

28. Stem rust pathotype nomenclature North American system
Sr5
Sr21
Sr9e
Sr7b
3+ [High]
33+ [High]
4 [High]
Set 1
Set 2
Set 3
Set 4
Set 5 T K S
Sr11
Sr6
Sr8a
Sr9g
33+ [High]
4 [High]
34 [High]
Sr36
Sr9b
Sr30
Sr17
0; [Low]
33+ [High]
34 [High]
Sr9a
Sr9d
Sr10
SrTmp
34 [High]
;1 [Low]
Sr24
Sr31
Sr38
SrMcN
;1 [Low]
33+ [High]
3+ [High]
4 [High]

29. Park stem rust work at USDA CDL
Sr gene
Race
AKA 5 6 8a 9b 9e 9g 11 13 17 24 30 31 36 38
1A.1R
# virulences
TTKSK
Ug99
TTKST
Ug99+Sr24 12
TTTSK
Ug99+Sr36
TRTTF
JRCQC
TTTTF 10
TPMKC
15B
34-1,2,7+Sr38
98-1,2,3,5,6 7
Kenya
Yemen
Ethiopia
U.S.A
Australia
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

30. Park stem rust work at USDA CDL
Sr gene
Race
AKA 5 6 8a 9b 9e 9g 11 13 17 24 30 31 36 38
1A.1R
# virulences
TTKSK
Ug99
TTKST
Ug99+Sr24 12
TTTSK
Ug99+Sr36
TRTTF
JRCQC
TTTTF 10
TPMKC
15B
34-1,2,7+Sr38
98-1,2,3,5,6 7
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

31. Park stem rust work at USDA CDL
Sr gene
Race
AKA 5 6 8a 9b 9e 9g 11 13 17 24 30 31 36 38
1A.1R
# virulences
TTKSK
Ug99
TTKST
Ug99+Sr24 12
TTTSK
Ug99+Sr36
TRTTF
JRCQC
TTTTF 10
TPMKC
15B
34-1,2,7+Sr38
98-1,2,3,5,6 7
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

32. Park stem rust work at USDA CDL
Sr gene
Race
AKA 5 6 8a 9b 9e 9g 11 13 17 24 30 31 36 38
1A.1R
# virulences
TTKSK
Ug99
TTKST
Ug99+Sr24 12
TTTSK
Ug99+Sr36
TRTTF
JRCQC
TTTTF 10
TPMKC
15B
34-1,2,7+Sr38
98-1,2,3,5,6 7
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

33. Park stem rust work at USDA CDL
Sr gene
Race
AKA 5 6 8a 9b 9e 9g 11 13 17 24 30 31 36 38
1A.1R
# virulences
TTKSK
Ug99
TTKST
Ug99+Sr24 12
TTTSK
Ug99+Sr36
TRTTF
JRCQC
TTTTF 10
TPMKC
15B
34-1,2,7+Sr38
98-1,2,3,5,6 7
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

34. Park stem rust work at USDA CDL
Sr gene
Race
AKA 5 6 8a 9b 9e 9g 11 13 17 24 30 31 36 38
1A.1R
# virulences
TTKSK
Ug99
TTKST
Ug99+Sr24 12
TTTSK
Ug99+Sr36
TRTTF
JRCQC
TTTTF 10
TPMKC
15B
34-1,2,7+Sr38
98-1,2,3,5,6 7
Yields in Australian cereal crops are generally low & hence genetic resistance is the most effective and economical means of diseas control
The ACRCP is a national program targeting control of cereal rust diseases by genetic resistance
Why is a nationally coordinated approach needed?
Rust diseases have caused significant losses to Australian cereal crops (some estimates are given)

35. TTKSK

36. Kenya Ethiopia South Africa Zimbabwe Uganda Kenya Ethiopia Sudan Yemen
“PTKSF” – HYPOTHETICAL ANCESTOR?
Kenya
Ethiopia
+Sr31
+Sr21
South Africa
Zimbabwe
PTKSK
TTKSF
+Sr21
+Sr24
Uganda
Kenya
Ethiopia
Sudan
Yemen
Iran
+Sr24
PTKST
TTKSK
TTKSP
Kenya
South Africa
+Sr36
+Sr24
South Africa
TTKST
TTTSK
Kenya

37. Known distribution of the “Ug99” lineage [courtesy Dr Dave Hodson FAO]

38. BL3 Facility, University of Minnesota

39. Sr15 genotypes infected with pt. TTKST (Kenya)
Sappo
Sicco
Maris Halberd
Timmo
Rossini
Thew
Norka 1 2 3 4 5 6 7

40. Sr21 and Sr45 genotypes infected with pts. TTKST & TTTSK
Einkorn [Sr21]
LMPG +Sr21 [Sr21]
Thornbill [Sr45] 1 2 3
TTKST (Ug99 +Sr24)
TTTSK (Ug99 +Sr36)

41. Diamondbrid-Janz mapping population, Ug99
Ug99
Ug99+Sr24
 Cultivar
Gene(s) 
TTKSK
TTKST
Diamondbrid
Sr2, Sr9g, Sr11
33+ 3+
Janz
Sr24
12-C
22+
Tested DH population with:
1. TTKSK (“Ug99”)
- expected a single gene segregation
- 88R : 33S [=2 genes]
2. TTKST (“Ug99 +Sr24”)
- expected a single geme segregation
- 85R : 36S [=2 genes]

42. Diamondbrid-Janz mapping population, Ug99
Ug99
Ug99+Sr24
 Cultivar
Gene(s) 
TTKSK
TTKST
Diamondbrid
Sr2, Sr9g, Sr11
33+ 3+
Janz
Sr24
12-C
22+
Tested DH population with:
1. TTKSK (“Ug99”)
- expected a single gene segregation
- 88R : 33S [=2 genes]
2. TTKST (“Ug99 +Sr24”)
- expected a single geme segregation
- 85R : 36S [=2 genes]

43. Diamondbrid-Janz mapping population, Ug99
Ug99
Ug99+Sr24
 Cultivar
Gene(s) 
TTKSK
TTKST
Diamondbrid
Sr2, Sr9g, Sr11
33+ 3+
Janz
Sr24
12-C
22+
Tested DH population with:
1. TTKSK (“Ug99”)
- expected a single gene segregation
- 88R : 33S [=2 genes]
2. TTKST (“Ug99 +Sr24”)
- expected a single geme segregation
- 85R : 36S [=2 genes]

44. Diamondbrid-Janz mapping population, Ug99
Pathotype TTKST (Ug99 +Sr24)
Diamondbrid
Janz
DJ 565
DJ 578
DJ 551
DJ 557
DJ 569
DJ 560 1 2 3 4 5 6 7 8

45. Sr24 carrying cultivars, Ug99
Ug99 +Sr24
 Cultivar
TTKSK
TTKST
Anlace
12+C 3+
Krickauff 2-
33+
Annuello
;1=
22+
Lang 0;
Clearfield Jnz
12-
2-C
Mira
;12-C 3
Cunningham
Mitre
Dakota
22-
Naparoo
12+
Datatine
Petrie
12-C
EGA Bullaring
2++3
QAL2000
EGA Jitarning
QALBis
EGA Wentworth
Sunsoft 98
22-C
GBA Sapphire
Tasman
Giles
Worrakatta
Guardian
Yenda
2+2++3
Janz

46. Sr24 carrying cultivars, Ug99
Ug99 +Sr24
 Cultivar
TTKSK
TTKST
Anlace
12+C 3+
Krickauff 2-
33+
Annuello
;1=
22+
Lang 0;
Clearfield Jnz
12-
2-C
Mira
;12-C 3
Cunningham
Mitre
Dakota
22-
Naparoo
12+
Datatine
Petrie
12-C
EGA Bullaring
2++3
QAL2000
EGA Jitarning
QALBis
EGA Wentworth
Sunsoft 98
22-C
GBA Sapphire
Tasman
Giles
Worrakatta
Guardian
Yenda
2+2++3
Janz

47. Sr24 carrying cultivars, Ug99
Ug99 +Sr24
 Cultivar
TTKSK
TTKST
Anlace
12+C 3+
Krickauff 2-
33+
Annuello
;1=
22+
Lang 0;
Clearfield Jnz
12-
2-C
Mira
;12-C 3
Cunningham
Mitre
Dakota
22-
Naparoo
12+
Datatine
Petrie
12-C
EGA Bullaring
2++3
QAL2000
EGA Jitarning
QALBis
EGA Wentworth
Sunsoft 98
22-C
GBA Sapphire
Tasman
Giles
Worrakatta
Guardian
Yenda
2+2++3
Janz

48. Sr24 carrying cultivars, Ug99 +Sr24 (TTKST)1 2 3 4 5 6
Agent
Janz
Mitre
Cunningham
EGA Jitarning
Krichauff

49. Other cultivars that appear likely to carry SrWeb
Ug99 +Sr24
Cultivar
Gene(s)
TTKST
Bolac
Sr6 Sr8a Sr17 Sr30 2-
Cadoux
Sr6
2+2++
Condor
Sr5 Sr8a Sr12
22+
EGA 2248
Sr5+
Goldmark
Sr2 Sr30
Kukri
Sr2 Sr8a Sr9g Sr30
2+2++3
Oxley
;12-C
Paterson
Sr8a Sr9g Sr12
12-
Rosella
Sr5 Sr7b Sr8a Sr12 Sr30
22-
Triller
Sr31
Waagan
Sr8a

50. Durum wheats 1 2 3 4 5 6 7 8 TRTTF [Yemen] Arrivato Caparoi Jandaroi
Kamilaroi [Sr13]
Kronos
Tamaroi
Wollaroi
Yallaroi [Sr9e] 4 3+ 2
2+3 3
33+
JRCQC [Ethiopia]

51. Key wheat rust pioneers
M. Newton
T. Johnson 1897–1979
E. C. Stakman
N. E. Borlaug
W.L. Waterhouse
I.A. Watson

52. Aggressiveness in wheat rusts
-experiences from Australia
- Four clear cases in which an introduced rust genotype has increased rapidly, and undergone a continental sweep by displacing existing genotypes:
Stripe rust race 134 [2002]
Leaf rust race 104 [1984]
Stem rust race 21 [1954]
Stem rust race 126 [1925]
- In each case, the “new” race did not have virulence attributes that conferred a fitness advantage (i.e. virulence for resistance genes)
- Evidence available strongly supports the hypothesis that each new genotype was more aggressive

53. Aggressiveness in wheat rusts
-experiences from Australia
- Four clear cases in which an introduced rust genotype has increased rapidly, and undergone a continental sweep by displacing existing genotypes:
Stripe rust race 134 [2002]
Leaf rust race 104 [1984]
Stem rust race 21 [1954]
Stem rust race 126 [1925]
- In each case, the “new” race did not have virulence attributes that conferred a fitness advantage (i.e. virulence for resistance genes)
- Evidence available strongly supports the hypothesis that each new genotype was more aggressive

54. Aggressiveness in wheat rusts
-experiences from Australia
- Four clear cases in which an introduced rust genotype has increased rapidly, and undergone a continental sweep by displacing existing genotypes:
Stripe rust race 134 [2002]
Leaf rust race 104 [1984]
Stem rust race 21 [1954]
Stem rust race 126 [1925]
- In each case, the “new” race did not have virulence attributes that conferred a fitness advantage (i.e. virulence for resistance genes)
- Evidence available strongly supports the hypothesis that each new genotype was more aggressive

55. Pathogen aggressiveness and resistance
1. Major gene resistance, eg Yr1
109 E141 A-
Yr1
Susceptible
+ Yr1
108 E141 A-
Yr1
Susceptible
Pathotype:

56. 110 E143 A+ Pathogen aggressiveness and resistance
2. Minor gene resistance, eg cv. Bowerbird
Bowerbird
Susceptible
110 E143 A+
Bowerbird has uncharacterised APR to stripe rust
Prior to 2002, it was considered MR-MS
It was rendered S by the new aggressive race
Why????:
- pathogen aggressiveness
[erosion of minor gene resistance]?
- minor gene virulence?
- aggressiveness + virulence?
Images courtesy of Dr Colin Wellings

57. 134 E16 A+ 110 E143 A+ Pathogen aggressiveness and resistance
2. Minor gene resistance, eg cv. Bowerbird
Bowerbird
Susceptible
110 E143 A+
Susceptible
Bowerbird
134 E16 A+
Bowerbird has uncharacterised APR to stripe rust
Prior to 2002, it was considered MR-MS
It was rendered S by the new aggressive race
Why????:
- pathogen aggressiveness
[erosion of minor gene resistance]?
- minor gene virulence?
- aggressiveness + virulence?
Images courtesy of Dr Colin Wellings

58. 134 E16 A+ 110 E143 A+ Pathogen aggressiveness and resistance
2. Minor gene resistance, eg cv. Bowerbird
Bowerbird
Susceptible
110 E143 A+
Susceptible
Bowerbird
134 E16 A+
Bowerbird has uncharacterised APR to stripe rust
Prior to 2002, it was considered MR-MS
It was rendered S by the new aggressive race
Why????:
- pathogen aggressiveness
[erosion of minor gene resistance]?
- minor gene virulence?
- aggressiveness + virulence?
Images courtesy of Dr Colin Wellings

59. 134 E16 A+ 110 E143 A+ Pathogen aggressiveness and resistance
2. Minor gene resistance, eg cv. Bowerbird
Bowerbird
Susceptible
110 E143 A+
Susceptible
Bowerbird
134 E16 A+
Bowerbird has uncharacterised APR to stripe rust
Prior to 2002, it was considered MR-MS
It was rendered S by the new aggressive race
Why????:
- pathogen aggressiveness
[erosion of minor gene resistance]?
- minor gene virulence?
- aggressiveness + virulence?
Images courtesy of Dr Colin Wellings

60. 134 E16 A+ 110 E143 A+ Pathogen aggressiveness and resistance
2. Minor gene resistance, eg cv. Bowerbird
Bowerbird
Susceptible
110 E143 A+
Susceptible
Bowerbird
134 E16 A+
Bowerbird has uncharacterised APR to stripe rust
Prior to 2002, it was considered MR-MS
It was rendered S by the new aggressive race
Why????:
- pathogen aggressiveness
[erosion of minor gene resistance]?
- minor gene virulence?
- aggressiveness + virulence?
Images courtesy of Dr Colin Wellings

61. 134 E16 A+ 110 E143 A+ Pathogen aggressiveness and resistance
2. Minor gene resistance, eg cv. Bowerbird
Bowerbird
Susceptible
110 E143 A+
Susceptible
Bowerbird
134 E16 A+
Bowerbird has uncharacterised APR to stripe rust
Prior to 2002, it was considered MR-MS
It was rendered S by the new aggressive race
Why????:
- pathogen aggressiveness
[erosion of minor gene resistance]?
- minor gene virulence?
- aggressiveness + virulence?
Images courtesy of Dr Colin Wellings

62. Pathogen aggressiveness and resistance
2. Minor gene resistance, eg cv. Tobruk triticale
increased stripe rusting in triticale cv. Tobruk in 2009
Images courtesy of Dr Colin Wellings

63. Pathogen aggressiveness and resistance
2. Minor gene resistance, eg cv. Tobruk triticale
increased stripe rusting in triticale cv. Tobruk in 2009
due to virulence for an uncharacterised minor gene
+ YrTobruk
Images courtesy of Dr Colin Wellings

64. Concluding remarks
separating the effects of virulence and aggressiveness, while significant for resistance breeding, is not always straightforward
caution is needed in communicating the concepts of virulence and agressiveness in the agricultural community
Australian breeders were successful in dealing with three incursions of aggressive rust isolates (two stem rust, one leaf rust), and despite some setbacks, continue to make good progress in relation to the most recent stripe rust incursion

65. © University of Sydney