Title: Spring Bread Wheat Improvement for Irrigated Environments
1Spring Bread Wheat Improvement for Irrigated
Environments
- Ravi Singh, Julio Huerta, Sybil Herrera, Pawan
Singh, Govindan Velu, Sukhwinder Singh and
Sridhar Bhavani
2Wheat 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
3Spring 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
4Spring 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
5Spring 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
6Irrigated 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
7Breeding 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
8Ciudad 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
9Why 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
10How 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
11Yield 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)
12Type 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
13The 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
14Grain 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
15Crossing 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
16Selection 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
17Selection 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
18Genetic gain in yield from Selected Bulk is 3.3
higher than Modified Pedigree(Source Simulation
studies- J. Wang and M. van Ginkel, Crop Science)
19Selected bulk retained 25 more crosses in the
final selected population (Source Simulation
studies- J. Wang and M. van Ginkel)
20Selection 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
21Handling 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
22Yield 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)
23Characterization 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
24Progress 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
25Shifting towards larger kernelsKernel weight of
1254 entries selected from 2009-2010 1st year
yield trials at Cd. Obregon, Mexico
PBW343
26Quality 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
27Variation for loaf volume of 486 new wheat lines
grown in Cd. Obregon during 2008-2009
28Predicted expansion of heat-stressed wheat ME5
mega-environment in India
29Future 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
30Segregating 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
31Advanced 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
32Future 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
33Future 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
34Rust menace- continued fight with an old enemy
Brown (leaf) rustPuccinia triticina
Yellow (stripe) rustPuccinia striiformis
Black (stem) rustPuccinia graminis
35Dr. 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)
36Boom-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
37Durable 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
38Genes 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
39Pleiotropic 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
40Leaf 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
41Identification 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
42Genetic 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
43Advances 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
44Durable 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)
- Lalbahadur
- LalbahadurLr34
- Thatcher
- RL6058 (ThatcherLr34)
- Chinese Spring (Lr34)
- Lr34 deletion mutant
Krattinger et al. Science 2009
45Advances 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.
46Controlled field epidemics remain the best
tool for selecting slow rusting resistance
47Adult 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
48Variation in resistance to yellow rust in 504 new
elite entries tested during 2009
Severity of susceptible checks 100S (N)
49Ug99 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
50Why 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
51Borlaug 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
- Planning for the Threat of Emerging Wheat Rust
Variants - Advocating and Coordinating Global Cooperation
- Tracking Wheat Rust Pathogens
- Supporting Critical Rust Screening Facilities in
East Africa - Breeding to Produce Rust Resistant Varieties
- Developing and Optimizing Markers for Rust
Resistance - Reducing Linkage Drag
- Discovering New Sources of Rust Resistance
- Exploring Rice Immunity to Rust
52Durable Rust Resistance in Wheat
53Methodology 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
54Pseudo 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
55Breeding 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
56Grain 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
57Alternative 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
58Diversity 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--------
59Ug99 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
60Grain-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
61Acknowledging 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