2014 bgri ammar.pdf
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Borlaug Global Rust Initiative Technical Workshop – 2014 Session: “Rust Resistance in Tetraploids” Ciudad Obregon, March 23, 2014
Advances in Breeding for Resistance to Stem Rust
Caused by Ug99 and Ethiopian Pgt Races in Durum Wheat
Ayele Badebo DZARC – EARO, Ethiopia
Karim Ammar, Abeyo Bekele, Alexandro Loladze, Susanne Dreisigacker, Roberto-Javier Peña & Masahiro Kishii Global Wheat Program - CIMMYT
Stem Rust on Durum Wheat Specificity of the pathogen and current presence
� Ug99+variants ■ Present in Kenya, Ethiopia, Yemen, Iran
■ Widespread resistance in most durum germplasm groups
� Ethiopian races, pre-dating Ug99 ■ Not as well characterized ■ Sr13+Sr9e combined virulence (Olivera et al. 2010)
■ Very little resistance (5%) in all germplasm groups worldwide (Olivera et al. 2010)
■ Confined to Ethiopia?, Sr13 virulence present in Turkey
Stem Rust on Durum Wheat Durum areas threatened by the “Ethiopian” races:
� Durum areas of Central India (1.0-1.5 million ha) ■ Through Yemen, most likely path as confirmed by migration of Ug99 ■ Stem rust (less virulent races) already endemic in the region
� Turkey, North-Africa, Middle-East (>5 million ha) ■ Less likely dissemination path, but cannot
be ignored ■ Sr13-virulence present in Turkey ■ Durum critical in these areas ■ Historically favorable climatic conditions for
the development of stem rust epidemics David Hodson et al. 2008
� Threat likely to increase with warming temperatures earlier in the cropping seasons as predicted by climate change scenarios
Breeding for Stem Rust Resistance in Durum Wheat Screening in Njoro-Kenya vs. Debre Zeit-Ethiopia
y = 0.9729x + 22.67R2 = 0.223
0
10
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-5 0 5 10 15 20 25 30 35 40 45
SR reading KENYA
SR re
adin
g ET
HIO
PIA
Breeding for Stem Rust Resistance in Durum Wheat The basis of our strategy
� Establishment of bi-annual screening program in Ethiopian “hot-spot” ■ Hosted by the Debre Zeit Ag. Res. Center ■ Artificial inoculation with mixture of relevant races (Ethiopian races + Ug99) ■ Screening of 1000s of lines annually:
• Resistance sources discovery for crossing • Resistance confirmation in new advanced lines • Genetic studies for resistance characterization
Photos: Dr. Ayele Badebo
Breeding for Stem Rust Resistance in Durum Wheat Rare resistance to start with in 2009… but enough to work with
50 – 70 S
80 – 100s
278
64
71.3
16.4
Reaction Class
Number of Lines
Percent of Total
10 MR – 20 MRMS 12 3.1 30 MR – 40 MSS 36 9.3
Data from Debre Zeit, off-season 2009
390 Elite Lines
Breeding for Stem Rust Resistance in Durum Wheat Emphasis in CIMMYT crossing program
296 456
268 219
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400
600
800
1000
1200
2009 2010 2011 2012
Num
ber o
f Cro
sses
Year
Crosses made for Stem Rust Resistance 2009 - 2012
Stem Rust Crosses
20 – 46% of program’s crossing effort
� Resistance Sources ■ CIMMYT Elite ■ European germplasm ■ North-American
germplasm ■ ICARDA germplasm ■ Genetic resources ■ Stocks with marked
genes (MAS)
Breeding for Stem Rust Resistance in Durum Wheat Selection stream: parallel selection Ethiopia/Mexico of new fixed lines
F3 Toluca
F2 Obregon
F6 PYT Obregon
F5 Toluca/Batan
F4 Obregon
F6 Off season Debre Zeit
F7 HR Batan
F7 Main season Debre Zeit
F8 Rep YT Obregon
F8 Off season Debre Zeit
Distribution Globally
Release Ethiopia
Selection for LR, YR, agronomic type, earliness and grain-fill
MEXICO: Selection for yield, drought tolerance, quality
ETHIOPIA: Selection for Stem Rust resistance
Breeding for Stem Rust Resistance in Durum Wheat Significant increase in resistant germplasm distributed globally
Number % Number % Number % Number %
Reaction Group of Lines Total of Lines Total of Lines Total of Lines Total
Resistant 20 13.2 5 3.3 17 10.7 26 12.0
Moderately Resistant 5 3.3 17 11.3 44 27.7 60 27.8
Useful for Stem Rust 25 16.4 22 14.6 61 38.4 86 39.8
Moderately Susceptible 12 7.9 19 12.7 5 3.1 2 0.9
Susceptible 115 75.7 109 72.7 93 58.5 128 59.3
N = 152 N = 150 N = 159 N = 216
43 IDYN+IDSN 44 IDYN+IDSN 45 IDYN+IDSN 46 IDYN+IDSN
Distributed 2011 Distributed 2012 Distributed 2013 Distributed 20142009: 3.1%
Breeding for Stem Rust Resistance in Durum Wheat Significant increase in resistant germplasm distributed globally while maintaining agronomic performance
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85 90 95 100 105 110 115 120 125 130 135
Num
ber o
f lin
es in
cla
ss
Grain Yield as % of Check JUPARE C2001
Yield Distribution under FULL IRRIGATION within germplasm distributed in 2013 and 2014 International Nurseries
ALL (N=304)
Stem Rust R/MR (N=124)
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20
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85 90 95 100 105 110 115 120 125 130 135
Num
ber o
f lin
es in
cla
ss
Grain Yield as % of Check JUPARE C2001
Yield Distribution under DROUGHT within germplasm distributed in 2013 and 2014 International Nurseries
ALL (N=291)
Stem Rust R/MR (N=115)
� Stem Rust Resistant lines have similar distribution than other lines ■ Yield Potential ■ Drought Tolerance ■ Quality attributes (gluten strength & yellow color)
Breeding for Stem Rust Resistance in Durum Wheat Stacking alien genes of resistance via MAS
Sr25/Lr19 7AL L. ponticum Durum w heat 1 PsyA1+PsyER4 Co-dominantFull phenotypic expression, routine use in parent characterization and MAS
cfa2123 Co-dominant
csKP81 Co-dominant
InheritancePhenotypic Validation and use in program
Sr22Full phenotypic expression, routine use in parent characterization and MAS
Location OriginSource
Originally Used
7AL T. boeticum Bread w heat
GeneMarker Designation
1: Transferred to durum by Dr. Adam Lukashewski, U.C. Riverside
Sr22 (cfa2123, cfa2019)
Sr25 (PSY1-EF2_ER4)
Photos: Susanne Dreisigacker
Breeding for Stem Rust Resistance in Durum Wheat Sr22 and Sr25 loci tightly linked , essentially inherited together, attempt at better gene stewardship…
Xgpw2242 -8.2 Xfba243 0.0 Xfba17 Xgpw4130 13.0 Xcfd62 18.7 Xfba231 22.4 XEF1R 33.9 Xfba127 38.9 Xfba109 58.4 Xbcd1438 59.4 Xgpw3201 65.3 Xgpw3234 76.2 Xfbb222 86.8 Xcfa2056 97.8 Xfbb79 98.9 Xfba71 99.5 Xfbb366 106.8 Xgpw3208 125.4 Xcfd6 129.5 Xgpw7313 136.1 Xpsr165 136.6 Xwmc182 137.7 Xpsp3050 138.4 Xcfa2110 147.5 XksuA5 168.5 Xbc9O10 169.6 Xglk478 174.5 XksuG12 178.2 Xcfa2123 193.3 Xfba69 198.7 Xpsp3094 Xgpw2252 210.6 Xtam51 219.9 Xcfa2019 224.0 Xcfa2293 232.4 XksuD2 232.8 Xfba350 244.7 Xwg232.1 253.6 Xwg232.2 253.8 Xcfa2040 256.2 XksuH9 267.5
7AL-1-0.39-0.71
7AL-18-0.9-1
Sr22 (cfa2123, cfa2019)
Sr25 (PSY1-EF2_ER4)
Chr. 7A (Courtot x C.S.)
DWSr22 x Elite 1
F1Sr22
DWSr25 x Elite 2
F1Sr25 X
Double-Cross Population
F2
F6
F8
Testing SR
Testing SR Yield, Drought
Quality
MAS
Breeding for Stem Rust Resistance in Durum Wheat Advanced lines with linked Sr22+Sr25
� GISH of L. Ponticum segment ■ Telomeric
� GISH of T. Boeticum segment ■ Not yet available
Photos: Masahiro Kishii
Breeding for Stem Rust Resistance in Durum Wheat Advanced lines with linked Sr22+Sr25: Characteristics
� Confirmed homozygocity for both genes ■ Markers stably homozygous in F6 – F8 head-rows ■ Stably resistant over 2-3 seasons at Debre Zeit
� Improved quality parameters ■ Better gluten strength than most local cultivars ■ Significantly higher yellow color than local cultivars
� Variable yield performance and drought tolerance ■ Obregon: some yield penalty due to lower kernel size ■ Ethiopia: under evaluation ■ Second round breeding started!!
CIMMYT – DZARC Joint Breeding Effort for Stem Rust Resistance in Durum Wheat: Conclusions
� Strategy of parallel Selection Mexico/Ethiopia has been successful ■ Significant progress in frequency of SR
resistant or moderately resistant lines in CIMMYT outgoing germplasm
■ Useful variability for yield potential, drought tolerance and quality maintained in new resistant germplasm
� Debre Zeit phenotyping platform has been key! ■ Testing facilities have been enhanced, effort
needs sustaining
� MAS with gene stewardship in mind provided valuable germplasm ■ If not usable for cultivar release, provides useful
parental stocks for further breeding
Stem Rust Resistance in Durum Wheat Research efforts to provide information and markers for breeding
� Association Mapping of Stem Rusts resistance ■ Beachell-Borlaug scholar Tesfaye Dugo Letta ■ Led y Prof. Tuberosa team, Univ. Bologna, Italy ■ Results from adult plant reaction and seedling published
(Letta et al., TAG, 2013; Letta et al., Plant Genome, 2014)
� Mapping of Stem Rust Resistance from Boohai ■ Beachell-Borlaug scholar Tesfaye Dugo Letta ■ Led y Prof. Tuberosa team, Univ. Bologna, Italy ■ Phenotyping done, mapping in process
� Mapping of Stem Rust Resistance from COCORIT ■ Collaboration with Dr. Curtis Pozniak, Univ. Saskatchewan ■ Preliminary results presented, manuscript in progress
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