This document summarizes efforts to develop drought tolerant wheat cultivars through genetic resources and coordinated phenotyping. It discusses exploiting existing genetic variation, conducting relevant field phenotyping across environments, and maximizing benefits from global public research. Genetic resources are exploited stepwise from landraces to related and alien species. Coordinated phenotyping is conducted locally, nationally, and internationally. Global research centers provide access to diversity and distribute materials globally to "squeeze the most" from germplasm. The document highlights several examples of this work.

1. 1
Delivering drought tolerance to those who
need it; from genetic resource to cultivar
R. M. Trethowan

2. 2
Stepwise exploitation of genetic resources
- do the easy things first
- exploit existing gene pool genetic variation
Coordinated and relevant field based phenotyping
- local, national & international levels
- trait validation across the target environment
Maximised benefits from global public goods breeding
- CGIAR centres and affiliates have access to diversity
- CGIAR centres a mandate to “tame” diversity
- National strategies to “squeeze” the most out of international germplasm
Three efficiencies to delivering drought tolerant
cultivars

3. 3
Stepwise exploitation of genetic resources
Adapted cultivars
Landraces
Related species
(crossable)
Alien species

4. Genetics of wheat yield in the northwestern NSW
Chromosome Number of significant
markers linked to
yield
1A 3
1B 1
1D 4
2A 6
5A 2
5B 4
6A 12
6D 3
7A 20
7D 6
4
Association analysis of a commercial wheat breeding program
Atta et al 2013
Based on 300
parents & derived
progeny tested in
multi-environment
trials over 3 years

5. Better breeding strategies to improve WUE:
targeting crown rot resistance in NSW
Crown rot in wheat
 Complex inheritance of resistance
 Plenty of genetic variation in the gene pool
 Low heritability
 Symptoms exacerbated under moisture stress
 Little progress over the past twenty years
Marker assisted recurrent selection
 Combine resistance QTLs in each population
 Yield testing in paired plots (+/- inoculation)
 Off season symptom testing
5
GRDC supported

6. Marker Assisted Recurrent Selection
Significant Markers - CSCR16/2/2-49/CUNNINGHAM//KENEDY/3/SUNCO/2*PASTOR(1RDRN#44)
 Symptom expression off season (controlled conditions)
 1AL, 1BL, 1DL, 2AL, 2BL, 2BS, 3AL, 3DL, 4AL, 4BL, 4DL,
4DS, 5AL, 5AS, 5BS, 5DL, 6AL, 6BL, 6DL, 7AS, 7BS
 Field
 1AL, 2BL, 3AL, 3B(?), 4BL, 4DL, 5BL,6BL
6

7. T. dicoccum or
durum
A. tauschii
AABBDD
DD
+
AABB
Synthetic wheat: the next step
Yield of a synthetic derivative compared to
the best local check in 30 environments
0
2
4
6
8
10
0 2 4 6 8 10
Average yield of SAWYT at site (t/Ha)
Yieldofline(t/Ha)
Local Check
Vorobey
Lage & Trethowan, 2008

8. Improving wheat WUE at Narrabri, NSW
Genotype Water use (mm) WUE kg ha-1 mm -1
D67.2/P66.270//AE.SQUARRO
SA (320)/3/Cunningham
273 18.0
Cunningham 261 13.9
Crusader 254 16.2
Envoy 283 12.0
Spitfire 258 14.6
8
Atta et al., 2013

9. Improved WUE is higher grain yield
9
y = 264.08x + 106.31
R² = 0.88**
3000
3500
4000
4500
5000
5500
10 12 14 16 18 20
Grainyield(kgha-1)
WUEGrain (kg ha-1 mm-1)
Envoy Cunningham
Synthetic/Cunningham
Spitfire

10. 10
Coordinated & relevant
phenotyping

11. Phenotyping at the local level: managing
heterogeneity
Walgett
NSW

12. Managing soil heterogeniety: EM38 assessment
at PBI Narrabri
1 - 25
175 - 215
Higher values indicate higher clay content, differences in texture & moisture

13. Indicates differences in soil texture & moisture content
Managing soil heterogeneity: EM38 assessment
at Narrabri

14. More drought tolerant wheat: national Managed
Environment Facility (GRDC supported)
Screening large numbers in
the field with an accurate
water balance
- define year type
- identify subsets
- estimate trait value
Rain shelters used to:
- evaluate subsets
- test population tails etc
Narrabri
Yanco
Merredin

15. Extended impact: global network of field based
managed environment facilities?
Australia (GRDC) India (GCP) China (GCP)
Narrabri New Delhi Beijing
Yanco Pune Hebei
Merredin Powarkheda Shanxi
Ludhiana Xinjiang

16. Genotype x tillage practice trials on two soil types at Narrabri: evaluation of a mapping population
Keeping screening relevant: selection for adaptation
to moisture conserving farming practices

17. The yield difference between zero-tillage and
conventional tillage: 2 sites x 2 years.
-600
-400
-200
0
200
400
600
800
0 20 40 60 80 100 120 140 160
Genotype
Yielddifferencekg/ha(ZT-CT)
Krichauff
Berkut

18. Significant QTL effects for yield under contrasting tillage
regimes on two soil types in 2 years
Chr Interval Treatment Soil type Additive
effect %
Allele
1B gwm268/wPt-3475 CT Grey v 8 K
1B wPt-1313/gmw140 CT Grey v 10 K
1D cdf19/wmc216 CT Red k 10 K
2D wPt-3728/cfd44 ZT Grey v 9 K
2D gmw484/wmc27 ZT Red k 9 B
5A cfa2155/wPt1370 ZT Grey v 25 B
5A cfa2115/wPt1370 CT Grey v 14 B
5A cfa2115/wPt1370 CT Red k 9 B
5B wmc99/wPt2373 ZT Grey v 12 B
Trethowan et al. 2012.

19. 19
Maximise the benefits of global
public goods research

20. 20
The CGIAR has:
 Multiple crop focus
 Access to genetic diversity
 Resources to introduce this diversity into adapted materials
 The network to distribute materials globally

21. Global distribution of CIMMYT International Wheat
Nurseries, 1994-2004
ESWYT
HRWYT
SAWYT
IAT
(Elite Spring Wheat Yield Trial (ESWYT), High Rainfall Wheat Yield Trial
(HRWYT) and Semi-Arid Wheat Yield Trial (SAWYT)) and the
International Adaptation Trial, 2001-2004
Matthews et al. 2008

22. Probe genotypes for soil borne constraints
(International Adaptation Trial)
Probe genotypes are:
 Genetically similar (either near-isogenic or same background)
 Similar yield in the absence of the stress
 Differentiate in the presence of the stress
Thirty seven different probe genotype comparisons in the IAT
including soil borne diseases and abiotic constraints:
Matthews et al., 2011
GRDC supported

23. 30
o
S
30
o
S
0
o
0
o
30
o
N
30
o
N
60
o
N
60
o
N
International Adaptation Trial locations 2001-2007
100 locations; 32 countries
165 trials
trial mean yield range 0.42 – 9.13 t/ha

24. Root Lesion Nematode_Isoline (Pratylencas thorneii)
NA
No Difference
Significant negative
Significant positive
Genotypes
Gatcher GS50A > Gatcher
30
o
S
30
o
S
0
o
0
o
30
o
N
30
o
N
60
o
N
60
o
N

25. The average genetic correlation of IATs at Roseworthy
(2001-2004), with global IATs
Matthews et al. 2011

26. CIMMYT Australia ICARDA Germplasm Evaluation
(CAIGE)
 Improved access to (and exploitation of) CIMMYT and ICARDA
germplasm by Australian wheat breeders
 Co-ordinated germplasm introduction, quarantine, evaluation &
data management
 Two-way flow of information between Australia and the CGIAR
centres (CAIGE website)
Supported by the GRDC

27. Locations where CAIGE yield trials are grown
CAIGE Yield Trial
approx 200 entries
4 organisations
9 locations
In addition, materials are screened for resistance to:
Rust
Septoria
Tan spot
Crown rot

28. Site groupings based on germplasm performance
Site grouping
1. Narrabri, North Star, Wongan
Hills
2. Toodyay, Junee
3. Roseworthy, Horsham
4. Esperance, Merredin
28

29. 1.Overall the SAWYT tends to have the
highest yield potential and ICARDA
materials the lowest.
2.The SAWYT best in Group 1
environments – Narrabri, NorthStar
and Wongan Hills – while the
ESWYT most suited to Group 2
environments – Junee and Toodyay.
3.ICARDA nurseries best adapted in
southern and western areas (i.e.
Group 3 and 4 environments)
4. Lines with high yield potential could
be identified from both CIMMYT &
ICARDA nurseries in all regions
29
Grain yield of CAIGE gemplasm in Australia

30. Acknowledgements
Funding:
GRDC, ACIAR, Generation Challenge Program & the Wheat
Research Foundation
Collaboration:
Australia’s wheat breeding groups & companies
CIMMYT, ICARDA, ICAR (India) & CAAS (China)
30