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Spring Bread Wheat Improvement for Irrigated Environments

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Title: Spring Bread Wheat Improvement for Irrigated Environments


1
Spring Bread Wheat Improvement for Irrigated
Environments
  • Ravi Singh, Julio Huerta, Sybil Herrera, Pawan
    Singh, Govindan Velu, Sukhwinder Singh and
    Sridhar Bhavani

2
Wheat Breeding at CIMMYT
  • Mexico based
  • Irrigated spring bread wheat improvement
  • Rainfed spring bread wheat improvement
  • Durum and triticale improvement
  • Germplasm enhancement
  • Regional based
  • Turkey-CIMMYT-ICARDA winter and facultative wheat
    improvement for CWANA region
  • CAAS-CIMMYT winter and facultative wheat
    improvement for China

3
Spring wheat mega-environments
  • ME1 Irrigated (36.1 area) Temperate
  • 1. High yield potential, lodging tolerance
  • 2. Water and nutrient use efficiency
  • 3. Resistance to three rusts
  • 4. Large white grain with leavened and flat
    bread quality

4
Spring wheat mega-environments
  • ME2 High rainfall gt500 mm (8.5 area) Temperate
  • 1. High yield potential, lodging tolerance
  • 2. Resistance to three rusts, septoria tritici
    and fusarium head blight
  • 3. Large red grain with leavened bread quality

5
Spring wheat mega-environments
  • ME5 Irrigated or High rainfall (7.1 area)
    Warmer
  • 1. High yield potential with early maturity,
    lodging tolerance
  • 2. Heat tolerance
  • 3. Resistance to rusts and spot blotch for low
    rainfall areas
  • Resistance to rusts and fusarium head blight
    for high rainfall areas
  • 4. Large white or red grain with leavened and
    flat bread quality or noodle quality depending
    on the country

6
Irrigated Spring Bread Wheat Improvement Program-
Targeted area 45 m ha
  • Irrigated Mega-environment 1 China,
    North-western India, Pakistan, Afghanistan,
    Iran, Turkey, Egypt, Mexico and Chile 30 m ha
  • Irrigated (Warmer) Mega-environment 5
    North-eastern, Central and Peninsular India,
    Tarai of Nepal, Bangladesh, Southern Pakistan,
    Sudan 10 m ha
  • High rainfall Mega-environment 2 West Asia and
    North Africa, Highlands of East Africa 5 m ha

7
Breeding Priorities
  • High and stable yield potential
  • Durable disease resistance
  • Rusts- Stem (Ug99), Stripe and Leaf
  • Fusarium Scab and myco-toxins
  • Septoria leaf blight, Spot Blotch, Tan Spot
  • Karnal bunt
  • Water use efficiency/Drought tolerance
  • Heat tolerance
  • Appropriate end-use quality
  • Enhanced Zn and Fe concentration
  • Adaptation in conservation Agriculture
  • Human Resource Development

8
Ciudad Obregon-Toluca/El Batan Shuttle
Breeding Backbone of CIMMYT Wheat Improvement
  • Hot-spot screening- Ecuador (YR), Kenya (SR)
  • International testing through yield screening
    nurseries

Cd. Obregón 39 m, High yield (irrigated) Drought
tolerance Leaf rust, stem rust
El Batán 2249 m Leaf rust, Fusarium
Mexico City
Toluca 2640 m Yellow rust Septoria
tritici Fusarium zero tillage with maize stubble
9
Why increase yield potential?
  • Necessary to meet the increasing demand (2
    annual) due to population increase
  • Increased production must come from the existing
    or reducing land resources
  • Increased yield potential is reflected in yield
    increases in farmers field even though the
    management remains the same

10
How to protect gains in yield potential?
  • Resistance to important diseases and pests
    (biotic stresses)
  • Tolerance to drought, heat, salinity, etc
    (abiotic stresses)
  • Resistance and tolerance to stresses in a variety
    has no cost to farmers

11
Yield stability
  • Capacity of a genotype (variety) to perform well
    under a range of environments under existing
    biotic and abiotic stresses
  • Environment at a location fluctuates annually
  • Easiest way to determine yield stability is to
    evaluate yield performance under a range of
    environments (wide adaptation)

12
Type of Crosses
  • Simple, three-way and four-way crosses an
    attempt to create new combinations of desirable
    genes (creation of a distinct genotype)
  • Backcross adds a genes or few genes from a
    source into an existing genotype
  • Single-backcross maintains most characteristics
    of a variety but still allows selection for
    several new genes

13
The Single-backcross Strategy
  • Increases the possibility of maintaining and
    reselecting desirable genes of the recurrent
    parent
  • Multiple genes or characters can be transferred
    simultaneously
  • Additional genes or characters from the donor
    parents can also be selected

14
Grain yields of wheat lines developed through
traditional (Simple and 3-way crosses) and
single-backcross approach
0.8 gt Check
10.7 gt Check
Cd. Obregon 2004-2005
15
Crossing details
  • Approximately 600 targeted simple crosses, 500
    single- backcross or three-way crosses per crop
    season
  • Approximately 300 F2 populations from simple
    crosses and 400 from single-backcross and
    three-way crosses
  • High emphasis to incorporate durable stem rust
    resistance in a range of germplasm carrying high
    yield potential, durable LR and YR resistance and
    quality characteristics

16
Selection Schemes
  • Various selection schemes can be applied
  • Selection schemes commonly used pedigree,
    unselected-bulk, selected-bulk, modified pedigree
    or bulk
  • Our preferred strategy selected-bulk

17
Selection Method Selected Bulk(Harvest and
thresh one spike from each of the selected plants
of a population as bulk)
  • Permits selection of unlimited number of plants
    that have good agronomic features and desired
    level of resistance
  • Increases possibility to identify transgressive
    segregants due to larger population sizes
  • Field operation is easy, fast and economic

18
Genetic gain in yield from Selected Bulk is 3.3
higher than Modified Pedigree(Source Simulation
studies- J. Wang and M. van Ginkel, Crop Science)
19
Selected bulk retained 25 more crosses in the
final selected population (Source Simulation
studies- J. Wang and M. van Ginkel)
20
Selection Strategy in Segregating Populations
  • Selected bulk from F1BC1/F1Top until F4/F5
  • Population sizes Space sown 400 plants in
    F1BC1/F1Top and F3-F5 1200 plants in F2 (2
    million plants/season with an average selection
    frequency of about 7-10)
  • Alternate segregating generations (F2-F5) under
    zero-tillage with maize stubble in Toluca and
    normal tillage in Cd. Obregon
  • Shuttling of stem rust resistance breeding F3 and
    F4 populations with Njoro, Kenya grown in
    off-season and then main season as F4 and F5. F5
    and F6 at Obregon.
  • Grain selection for size (45 mg and above) and
    plumpness in each generation through sieving
  • Selected plants harvested individually (or one
    spike harvested in Toluca) in F5 and F6
    generations and plants/spikes with good grain
    characteristics retained

21
Handling of Advanced Lines
  • Advanced lines (F6) from individual spikes in F5
    populations harvested in Toluca planted in Cd.
    Obregon as small plots. Selected plots planted in
    Toluca and El Batan as PC. Selected lines form
    yield trials in Cd. Obregon.
  • Advanced lines (F5 or F6) from individual plants
    harvested in Cd. Obregon planted as F6/F7 at El
    Batan and Toluca in small plots and selected
    lines form yield trials in Cd. Obregon.
  • Yield trials-1st year (alpha-lattice design, 3
    reps) sown on raised bed system in Cd. Obregon,
    and sets of PC are grown in Cd. Obregon (leaf
    rust)
  • Best lines selected based on yield and other
    traits and grain from Cd. Obregon used for
    quality analysis and for further disease and
    agronomic evaluations at Toluca, El Batan and
    Njoro (Kenya) and also multiplied in El Batan as
    Candidates for International Yield and Screening
    Nurseries (ESWYT, IBWSN, HRWYT, HRWSN)
  • 2nd year of yield trials in Cd. Obregon for
    selected lines conducted under five environments
    and seed multiplied in Mexicali for International
    Nursery. Simultaneous stem rust, yellow rust and
    leaf rust testing conducted in Kenya, Ecuador and
    cd. Obregon, respectively.
  • All data combined and used in selecting lines for
    International Yield Trials and Screening Nurseries

22
Yield testing of advanced lines at Cd. Obregon,
Mexico2009-2010 season
  • 1st year yield trials or YT (5000 entries
    including checks) 30 entries/trial, 3 reps,
    alpha-lattice design
  • raised bed 5-irrigations
  • (small plots or PC planted for seed)
  • 2nd year yield trials or EYT (500 entries
    including checks) 30 entries/trial on beds (20
    entries trial on Flat), 3 reps, alpha-lattice
    design
  • Raised bed, zero tillage-5 irrigations (gt8 t/ha)
  • Flat-5 irrigations (gt8 t/ha)
  • Raised bed-2 irrigations (4-5 t/ha)
  • Raised bed- drip irrigation (2.5-3 t/ha)
  • Raised bed-Late (85 days delay) sown- (gt4 t/ha)
  • (small plots or EPC planted for seed)

23
Characterization of EPC entries
  • Diseases
  • Leaf rust- seedling and field (El Batan and Cd.
    Obregon)
  • Yellow rust- seedling and field (Toluca and
    Ecuador)
  • Stem rust- seedling and field off- and
    main-seasons (Kenya)
  • Septoria tritici- Toluca
  • Fusarium- El Batan
  • Karnal Bunt- Cd. Obregon
  • Tan (yellow) spot- El Batan greenhouse
  • Stagnospora nodorum blotch- El Batan greenhouse
  • Spot blotch- Aguas Frias
  • Various quality traits including grain weight
  • Agronomic traits height, heading, maturity,
    lodging

24
Progress in grain-yield potential of new breeding
lines after one 5-year cycle of selection (Cd.
Obregon 2004-05 and 2009-2010)
Breeding is science, art, passion, hard work
number game
12 yield gain
2004-05 4814 entries
2009-10 4956 entries
0.6
8.9
PBW343
25
Shifting towards larger kernelsKernel weight of
1254 entries selected from 2009-2010 1st year
yield trials at Cd. Obregon, Mexico
PBW343
26
Quality profiles of newer CIMMYT wheats Changing
profiles of high and low molecular weight
glutenins in CIMMYT wheats for bread making
quality as well as reduction of 1BL.1RS
translocation
Source R.J. Peña
27
Variation for loaf volume of 486 new wheat lines
grown in Cd. Obregon during 2008-2009
28
Predicted expansion of heat-stressed wheat ME5
mega-environment in India
  • Current 2050

29
Future Gains in Yield Potential and Yield
Stability under Climate Change
  • Targeted improvement of high yielding, widely
    adapted wheats Identifying superior
    transgressive segregates
  • Wide incorporation of white floured 7DL.7Ag alien
    segment carrying Lr19/Sr25 genes quantum jump of
    10-12 in yield potential
  • Utilization of genetic resources, e.g. synthetic
    wheats
  • Shifting maturity towards earliness and selecting
    under heat-stress at hot-spot sites
  • Application of physiological tools in selection
  • Variety mixtures must be explored as an
    alternative strategy in heat and other stressed
    environments

30
Segregating populations for selection in Toluca
in 2010
Segregating populations Plot numbers
F1 Top BWIR 1-668
F2SR BWIR 1-609
F2 FUS BWIR 610-637
F2 Harvest Plus BWIR 638-723
F3 BWIR 1-693
F3HPlus BWIR 1-43
F4Stem Rust BWIR 1-817
F5Stem Rust BWIR 1-621
31
Advanced lines for selection in Toluca El Batan
in 2010
Advanced lines Plot numbers Entries (No.)
C45IBWSN 1-1258 1258
PC BWIR (white grain) 1-5868 5868
PC BWIR (red grain) 10001-10715 715
F6 BWIR (white Grain) 1-22905 22905
F6 BWIR (red Grain) 30001-32366 2366
F6 Fus BWIR (white grain) 35001-35443 443
F6 Fus BWIR (red grain) 37001-37729 729
F5-F6 Harvest Plus 1-763 763
HP South Asia 1-251 251
HP Head Seln Lines 1-965 965
HP Head Seln Lines BWIR 1-243 243
PC Wide Cross 1-133 133
32
Future Challenges- The Population Monster
Countries with highest population in 2050 and
change relative to 2009
Rank Country Population (million) Increase (million) Change
1 India 1614 416 35
2 China 1417 71 5
3 United States of America 404 89 28
4 Pakistan 335 154 85
5 Nigeria 289 134 86
6 Indonesia 288 58 25
7 Bangladesh 222 60 37
8 Brazil 219 25 13
9 Ethiopia 174 91 110
10 Dem. Republic of Congo 148 82 124
11 Philippines 146 54 59
12 Egypt 130 47 57
13 Mexico 129 19 17
14 Russian Federation 116 -25 -18
15 Viet Nam 112 24 27
620 million more people just in South Asia by
2050 Population of USA and Brazil in 2009
33
Future challenges- Wheat Yields 2008
Average by 2020 to produce 760 mlln tons
World average 2008
UN/FAO production goal for wheat 4 tons/ha by 2020
34
Rust menace- continued fight with an old enemy
Brown (leaf) rustPuccinia triticina
Yellow (stripe) rustPuccinia striiformis
Black (stem) rustPuccinia graminis
35
Dr. Roy Johnson (1935-2002)
Durable Resistance
Resistance, which has remained effective in a
cultivar during its widespread cultivation for a
long sequence of generations or period of time in
an environment favourable to a disease or pest.
Types of Resistance
  • Monogenic Race-specific Major genes
    Hypersensitive (Boom Bust)
  • Polygenic Race-nonspecific Minor genes Slow
    rusting/ Partial (Durable)

36
Boom-and-Bust Race-Specific Genes for leaf
rust resistance in Northwestern Mexico
    Year Year  
Variety Resistance gene Released Breakdown Race
Bread Wheat
Yecora 70 Lr1, 13 1970 1973 ?
Tanori 71 Lr13, 17 1971 1975 ?
Jupateco 73 Lr17, 2731 1973 1977 TBD/TM
Genaro 81 Lr13, 26 1981 1984 TCB/TB
Seri 82 Lr23, 26 1982 1985 TCB/TD
Baviacora 92 Lr14b, 2731 1992 1994 MCJ/SP
Durum Wheat
Altar 84 LrAlt 1984 2001 BBG/BN
Jupare 2001 LrAlt, 2731 2001 2007 BBG/BP
37
Durable Resistance to Rust Diseases Why?
  • Numerous races of rust pathogens
  • Mutating and migrating nature of rust pathogens
  • Annual virulence analysis and monitoring required
  • Most known race-specific genes ineffective in one
    or more wheat growing regions
  • Slow variety turnover in many countries
  • Opportunity to break-out of Boom-and-Bust
    cycles and focus breeding for other important
    traits

38
Genes involved in durable, slow rusting
resistance to rust diseases
  • Minor genes with small to intermediate effects
  • Gene effects are additive
  • Resistance does not involve hypersensitivity
  • Genes confer slow disease progress through
  • 1. Reduced infection frequency
  • 2. Increased latent period
  • 3. Smaller uredinia
  • 4. Reduced spore production

39
Pleiotropic Slow Rusting GenesLr34 /Yr18/Pm38
and Lr46/Yr29/Pm39Lr67/Yr46/Pm?
With Lr46 Without Lr46
  • Components of slow rusting are under pleiotropic
    genetic control, i.e., the same resistance
    mechanism controls all components
  • Formation of cell wall appositions, instead of
    hypersensitivity

40
Leaf tip necrosis and slow rusting resistance
Leaf tip necrosis associated with Lr46
  • Lr34/Yr18/Pm38, Lr46/Yr29/Pm39 and Lr67/Yr46/Pm?
    linked to some level of leaf tip necrosis
    expression
  • Slow rusting resistance without leaf tip necrosis
    also known

LalbahadurLr46
Lalbahadur
41
Identification and characterization ofslow
rusting resistance
  • High or susceptible infection type in the
    seedling growth stage
  • Lower disease severity or rate of disease
    progress in the field compared to susceptible
    check
  • Brown rust High (compatible) infection type in
    the field
  • Yellow rust Infection type not a reliable
    criteria due to systemic growth habit
  • Stem rust Variable size of pustules- bigger near
    nodes

42
Genetic basis of durable resistance to rust
diseases of wheat
Rust
Susceptible
100
80
1 to 2 minor genes
60
40
2 to 3 minor genes
20
4 to 5 minor genes
0
20
0
10
30
50
40
Days data recorded
  • Relatively few additive genes, each having small
    to intermediate effects, required for
    satisfactory disease control
  • Near-immunity (trace to 5 severity) can be
    achieved even under high disease pressure by
    combining 4-5 additive genes

43
Advances in Molecular Mapping of Slow Rusting
Resistance Genes
  • Several Genomic locations (QTLs) known
  • Developing and characterizing mapping populations
    that segregate for single resistance genes
  • Single gene based populations for 2 or 3
    undesignated genes now available at CIMMYT
  • Very difficult to characterize populations
    segregating for minor genes that have relatively
    small effects
  • Gene-based markers for relatively larger effect
    slow rusting genes becoming reality
  • Gene Lr34/Yr18/Pm38 cloned and gene-based marker
    available
  • Significant progress made towards cloning of
    Lr46/Yr29/Pm39

44
Durable pleiotropic resistance gene Lr34/Yr18/Pm38
Perfect marker for Lr34 -veLr34sp
veLr34spA (multiplex)
ABC (ATP Binding Cassette) transporter of PDR
(Pleiotropic Drug Resistance) subfamily
1 2 3 4 5 6
  • Cloning of Lr34/Yr18/Pm38
  • Single gene based fine mapping populations
  • Gamma-ray induced deletion stocks
  • Azide-induced mutations
  • Precision phenotyping
  • Partnership (CIMMYT, CSIRO and Univ. of Zurich)
  1. Lalbahadur
  2. LalbahadurLr34
  3. Thatcher
  4. RL6058 (ThatcherLr34)
  5. Chinese Spring (Lr34)
  6. Lr34 deletion mutant

Krattinger et al. Science 2009
45
Advances in breeding for slow rusting resistance
to brown and yellow rusts at CIMMYT
  • 1970s Wheat lines with intermediate levels of
    slow rusting resistance selected.
  • 1990s Wheat lines with near-immune level of
    resistance developed through intercrossing
    diverse sources of resistance followed by
    selection of transgressive segregants.
  • 2000s Targeted introgression of resistance into
    adapted cultivars and genotypes resulting in
    high-yielding wheats with high levels of
    resistance.

46
Controlled field epidemics remain the best
tool for selecting slow rusting resistance
47
Adult plant leaf rust responses of 144
race-specific gene carrying and 360 seedling
susceptible new elite entries in El Batan, Mexico
2009
Susceptible checks 100 severity
0-15 severity
48
Variation in resistance to yellow rust in 504 new
elite entries tested during 2009
Severity of susceptible checks 100S (N)
49
Ug99 migration and evolution current status
Iran
2007
Pakistan
  • 1988 Uganda
  • 2002 Kenya
  • 2003 Ethiopia
  • 2006 Yemen and Sudan
  • 2006 Sr24 virulent mutant-Kenya
  • 2007 Iran
  • 2007 Sr36 virulent mutant-Kenya
  • 2007 Sr24 virulent mutant-caused epidemic in
    Kenya
  • 2008 2009 Similar races found in South Africa

2006
Yemen
Sudan
2006
2003
1998
2002
50
Why Ug99 is a threat to wheat producing countries?
  • Historical importance of stem rust
  • Span of susceptible wheat varieties on gt80 area
  • Favorable environment (dew/rain and temperatures)
  • Mountains and other areas for off-season survival
  • Continued evolution
  • Early epidemics can cause gt70 losses
  • If measures not taken, estimated 10 losses in
    production in South Asian countries alone can be
    worth approx. US1.5 billion and will provoke
    sharp increases in wheat prices

51
Borlaug Global Rust Initiative
A multi-institutional partnership for
systematically reducing vulnerability of global
wheat crop to wheat rusts
  • Durable Rust Resistance in Wheat Project-
    Objectives
  1. Planning for the Threat of Emerging Wheat Rust
    Variants
  2. Advocating and Coordinating Global Cooperation
  3. Tracking Wheat Rust Pathogens
  4. Supporting Critical Rust Screening Facilities in
    East Africa
  5. Breeding to Produce Rust Resistant Varieties
  6. Developing and Optimizing Markers for Rust
    Resistance
  7. Reducing Linkage Drag
  8. Discovering New Sources of Rust Resistance
  9. Exploring Rice Immunity to Rust

52
Durable Rust Resistance in Wheat
53
Methodology used for identifying adult plant
resistance to Ug99 in current wheat materials
  • Field evaluation of advanced breeding lines in
    Kenya/Ethiopia
  • Greenhouse seedling tests for susceptibility to
    Ug99 at USDA-ARS Lab. in St. Paul, Minnesota, US
  • Characterization of pseudo-black chaff phenotype
    and application of Sr2 molecular marker
  • Identified APR Sources Kingbird, Kiritati,
    Juchi, Pavon, Parula, Picaflor, Danphe, Chonte

Kingbird-the best source of APR
54
Pseudo black-chaff
Durable adult-plant resistance (APR) to stem rust
  • Sr2-Complex
  • (Sr2 and other minor genes)
  • Sr2 transferred to wheat from Yaroslav emmer in
    1920s by McFadden
  • Sr2 is linked to pseudo-black chaff
  • Sr2 confers only moderate levels of resistance
    (about 30 reduction in disease severity)
  • Adequate resistance achieved when Sr2 combined
    with other unknown genes
  • Essential to reduce/curtail the evolution of Ug99
    in East Africa and other high risk areas

Sr2 present
Sr2 absent
55
Breeding for durable, adult-plant resistance at
CIMMYTMexico (Cd. Obregon-Toluca/El Batan)-
Kenya International Shuttle Breeding a
five-year breeding cycle)
Cd. Obregón 39 masl High yield (irrigated),
Water-use efficiency, Heat tolerance, Leaf rust,
stem rust (not Ug99)
Njoro, Kenya 2185 masl Stem rust (Ug99
group) Yellow rust
El Batán 2249 masl Leaf rust, Fusarium
Toluca 2640 masl Yellow rust Septoria
tritici Fusarium Zero tillage
  • Shuttle breeding between Mexico and Kenya
    initiated in 2006
  • gt1000 F3/F4 populations undergo Mexico-Kenya
    shuttle
  • High yielding, resistant lines from 1st cycle of
    Mexico-Kenya shuttle under seed multiplication
    for international distribution in 2010

56
Grain yield performance comparison Mexico
Shuttle vs. Mexico-Kenya Shuttle Breeding, Cd.
Obregon 2009-2010
Mexico shuttle n3903
Mexico-Kenya shuttle N1053
8-9 entries
PBW343
No effect of selection in Kenya on grain yield
performance
57
Alternative approaches
  • Use effective race-specific resistance genes in
    combinations aided by molecular markers
    (short-term) few useful genes with markers
  • Develop cassettes of durable or unutilized
    race-specific resistance genes- GMO solution
    (long-term) need a strong collaborative cloning
    effort

58
Diversity and utilization race-specific
resistance genes effective to Ug99 group of races
Seeding infection types
  • About 20 resistance genes have potential (Sr13,
    14, 22, 25, 26, 27, 28, 29, 33, 35, 39, 40, 43,
    44, 45, Tmp, 1A.1R, Sha7 and a few more)
  • Virulence known in other races for seven genes
    (Sr13, 14, 27, 25, 28, Tmp, 1A.1R)
  • Immediate value Sr22, 26, 35, Huw234, Sha7 and
    Sr13, 14, 25, 1A.1R and Tmp for use in
    combinations
  • Translocations being shortened to reduce the
    negative effects and new genes being searched
  • Molecular markers essential for selecting gene
    combinations

Susceptible
-------Resistant--------
59
Ug99 Stem Rust Resistance in 728 new CIMMYT wheat
lines developed after one cycle of breeding
(2006-2010)
  Stem rust Entries Entries
Resistance category severity and reaction Number Percent
Adult-plant resistance
Near-immune resistant 1 MS-S 120 16.5
Resistant 5-10 MS-S 178 24.5
Resistant-moderately resistant 15-20 MS-S 199 27.3
Moderately resistant 30 MS-S 63 8.7
Mod. resistant-mod. susceptible 40 MS-S 34 4.7
Moderately susceptible 50-60 MS-S 27 3.7
Mod. susceptible-susceptible 70-80 MS-S 5 0.7
Susceptible 100 S 2 0.3
CACUKE (Susceptible check) 100 S (N)
Race-specific genes
Sr25 1-10 R-MR 17 2.3
Sr26 5-10 R-MR 9 1.2
SrTmp 1-40 MR-MS 49 6.7
SrHuw234 30 MR-MS 1 0.1
SrSha7 1-10 R-MR 19 2.6
Other unknown genes 1-5 R-MR 5 0.7
60
Grain-yield performance of 298 entries with APR
(NIR and R categories) to Ug99 stem rust compared
with all 728 lines retained after one
5-year-breeding-cycle (Cd. Obregon 2009-2010)
39.3
31.2
11.1
6.7
About 90 lines also highly resistant to leaf
rust and yellow rust and resistance of about 60
lines based on APR
61
Acknowledging agencies supporting bread wheat
improvement rust research
Bill and Melinda Gates Foundation through
DRRW Project CSISA Project Harvest Plus
Project Syngenta Foundation
Governments ICAR, India USAID, USA USDA-ARS,
USA SDC, Switzerland ACIAR, Australia
Farmers organizations Agrovegetal,
Spain Cofupro, Mexico GRDC, Australia Patronato-So
nora, Mexico
Thank you
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