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Wheat production and genetic Wheat production and genetic improvement in China: progress improvement in China: progress and perspectivesand perspectives
Zhong-hu He
Chinese Academy of Agricultural Sciences, CAASGlobal Wheat Program, CIMMYT
OutlinesOutlines Wheat production Progress in breeding Marker development and application Perspectives
Wheat productionWheat production
Crop Area (mha) Production (mt) Yield (t/ha)
Rice 30.3 205 6.8
Wheat 24.0 124 5.1
Maize 36.7 217 5.9
Major crop production in China, average in 2013 and 2014Major crop production in China, average in 2013 and 2014
Unique Chinese wheatUnique Chinese wheat The largest producer and consumer in the world, with
the smallest farmer size (0.5ha)
Early maturity suits for double cropping system
Traditional products such as noodles and steamed
bread share 85% market
Chinese wheat production has a great influence on
prices at both domestic and international market
Chinese wheat production zonesChinese wheat production zones
Wheat/maize rotation 75%
Wheat/rice rotation 20%
Single wheat 5%
China’s wheat production and averaged China’s wheat production and averaged yield, 2000-2014yield, 2000-2014
Factors for improving productionFactors for improving production Very favorable policy for grain production, price
doubled, subside policy for seed and machinery
Two varietal replacements
Promotion of mechanization
Significant investment in research and extension
Constrains: high costConstrains: high cost Domestic wheat is 35% more expensive than
international market, associated with increased inputs
and devalue of Chinese Yuan
High inputs caused water shortage and pollution
Strong competition between wheat and maize/cash
crops, farmers shift interest to non-farming activities
Constrains: diseasesConstrains: diseases Head scab is shifting to the Yellow and Huai Valleys,
due to climate change and continuous wheat-maize
rotation,10 mha extremely serve scab in 2012
New yellow rust race V 26 made all varieties carrying
Yr26/Yr24 lose resistance
Sharp eye spot, powdery mildew, and leaf rust are
more serious than before
Constrains: climate changeConstrains: climate change
Wheat type changed, facultative type replaced winter
type, spring type replaced facultative type
Heading dates advanced about 7 days, maturity
maintained unchanged, grainfilling period extended
Temperature and rainfall fluctuation, extremely low
temperature before heading in 2013 made 2 million ha
wheat yield reduction by 20%
Progress in breedingProgress in breeding
1-Yield improvement1-Yield improvement Yield potential has always been the top priority
Combination of elite variety and crop management
Delayed sowing and early maturity of wheat allows long season and
high yield for maize,13-15t/ha under wheat/maize rotation system in
one year
y = -93.76 + 0.05 xR 2 = 0.69, P < 0.01
7.5
8
8.5
9
9.5
10
1980 1985 1990 1995 2000 2005 2010Year of release
Gra
in
yiel
d (t
ha
-1)
y = -725.58 + 0.38 xR2 = 0.45, P < 0.01
30
33
36
39
42
45
48
51
54
1980 1985 1990 1995 2000 2005 2010Year of release
TG
W (
g)
Yield potential improvement in Henan,1980-2008Yield potential improvement in Henan,1980-2008
Zheng et al, 2011, Field Crop Research,12: 225-233
y = 0.062 x - 116.11
R 2 = 0.67, P < 0.01
6.00
6.50
7.00
7.50
8.00
8.50
9.00
1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
Gra
in y
ield
(M
g h
a -1
)
A) y = 156.07 x - 292538
R 2 = 0.61, P < 0.01
12000
15000
18000
21000
24000
1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
Ker
nel
s m
-2
B)
Yield potential improvement in Shandong, 1970-2008Yield potential improvement in Shandong, 1970-2008
Xiao et al, 2012, Crop Science, 52:44-56
Synthetic derived wheat increase yield by 11.5%Synthetic derived wheat increase yield by 11.5%Type Yield (kg/ha) Grain number/m2 TKW (g)
SD 9231a 18907a 48.1a
NSD 8280b 17886b 45.4b
Increase 11.5% 5.7% 5.9%
SD= synthetic derived, NSD = Not synthetic derived.Different letters indicate significant at 5%.Tang et al, 2014, Crop Science, 55: 98-112
Yield gains after 2000Yield gains after 2000 Continuous yield increase achieved, new varieties with
compact plant type and higher HI, better tolerance to heat
and drought during grainfilling period
KN/m2 and/or KW contribute to yield increase
Germplasm is the key factor for yield improvement, use of
elite parents such as Zhou 8425B and synthetic wheat
2- Coping with climate change2- Coping with climate change Screening for broad adaptation
Breeding for heat tolerance and water use efficiency
Planting winter wheat in spring wheat area
Normal planting, Oct 3, 2008
XY81 XN1376
Late planting, Nov 6, 2008
XY81 XN1376
Screening under different planting datesScreening under different planting dates
Screening for heat tolerance at plastic houseScreening for heat tolerance at plastic house
Winter wheat in spring wheat area, yield Winter wheat in spring wheat area, yield increase by 30%, early maturity 10 daysincrease by 30%, early maturity 10 days
Zhongmai 175 outyielded check Zhongmai 175 outyielded check variety at various irrigationsvariety at various irrigations
Zhongmai 175 outyielded check variety Zhongmai 175 outyielded check variety at six different fertilizer levelsat six different fertilizer levels
Summary-breedingSummary-breeding Continuous yield increase has been achieved in China
Development of climate-resilient variety is possible,
genotypes with high yield potential, resource use
efficiency, and broad adaptation can be identified by
multi-location testing
Fast grainfilling rate is a key selection criteria
Molecular marker development Molecular marker development and application and application
ApproachApproach Focus on gene specific markers, easy use and low cost
Molecular marker development and validation
Optimize available markers from other institutes
Establish high throughput platform
Yellow pigment controlled by Psy genes is an important
factor influencing product color, cloning Psy 1 gene by
comparative genomic approach
Develop gene specific markers based on allelic variations
Validate markers in Chinese wheat varieties
ExampleExample
Cloned Cloned PsyPsy genes on wheat chr 7A and 7B genes on wheat chr 7A and 7BAllele Coding seq
(bp)Intron cDNA (bp) Deduced amino acids
5’UTR ORF 3’UTR Residues Mass (kD)
PSY-A1 4177 bp 5 221 1284 303 428 47.8
PSY-B1 3313 bp 5 222 1263 156 421 47.0
ZMU 32636
1 4177PSY-A1
1 2 3 4 5 6
1 3313PSY-B1
1 2 3 4 5 6
He et al, 2008, TAG, 116: 213-221
Psy-A1a
Psy-A1b
Psy-A1c
Allelic variants for the Allelic variants for the Psy-A1Psy-A1 gene on chr 7A gene on chr 7A
He et al, 2008, TAG, 116: 213-221
PCR amplification with YP7APCR amplification with YP7ACultivars with high YP content
231 bp194 bp
194 bp
231 bp
Cultivars with low YP content
Validation of Validation of YP7AYP7A with Chinese varieties with Chinese varietiesAllele Accession no Mean (mg/kg) Range
Psy-A1a 130 1.80 a 0.62-3.42
Psy-A1b 87 1.35 b 0.35-2.88
Different letters indicate significant difference at P<0.05
He et al, 2008, TAG, 116: 213-221
Markers for quality traitsMarkers for quality traits HMW-GS: Ax2*, Bx7, Bx 7OE, Bx17+By18, Bx14+By15…
LMW-GS: 20 markers for Glu-A3 and Glu-B3
PPO: PPO16, PPO18, PPO29, PPO33
Yellow pigment: Psy-A and Psy-B
Grain hardness: Pina-D1b, Pinb-D1b, Pinb-D1p
Sprouting tolerance: Vp1B3
Starch: Wx-A1, Wx-B1, Wx-D1
Trait Locus number Marker number Allele number
Quality trait 18 58 72
Agronomic trait 11 25 21
Disease resistance 2 14 9
Total 31 97 102
CAAS-CIMMYT 18 40 48
Summary of gene specific markers in wheatSummary of gene specific markers in wheat
Liu et al, 2012, TAG, 125: 1-10
Marker applicationMarker application 100 markers are routinely used for parent
characterization and advanced lines confirmation Work together with leading programs on variety
development, focused on processing quality and disease resistance
Three varieties have been released
LX987 CA998Donor YM34/3*LX987 YM34/3*LX987
(Dx5 、 1BL/1RS )
CA1062
CA998CA998 CA1062CA1062
New varieties from MAS programNew varieties from MAS program
Disadvantages of gel based markersDisadvantages of gel based markers All gene specific markers in wheat are PCR-gel based
markers, limitation in breeding application Higher cost in labor and chemistries Longer time Less flexibility and accuracy, needs good skills and quality
chemistries
Kompetitive Allele Specific PCR (KASP) is the most desirable technology for SNP genotyping
Desirable flexibility High-throughput Low cost
Framework to develop KASP assays Framework to develop KASP assays Development 32 KASP markers public available database 40 KASP markers developed by CAAS-CIMMYT Include all available gene specific markers
Validation by SNPLINE from LGC 384 Chinese varieties Four mapping populations
Application Development of central facility for genotyping Development of breeding chip by adding more SNPs associated with
phenotypes
16 PCR plates (96 samples)/day
1536 genotypes/day
KASP 12-48 times efficient than PCR markersKASP 12-48 times efficient than PCR markersManual PAGE genotyping: 2 or 3 persons KASP genotyping: 1 person
48 PCR plates (384/1584)/day
18,432-86,032 genotypes/day
Tested data on KASP from ChinaTested data on KASP from China Time: 1500 varieties can be genotyped with 100
available markers in two days
Cost: 3 cents/data point excluding DNA extraction
High consistency with PCR markers
Summary-markersSummary-markers Comparative genomic approach has been successfully
used in marker development and validation
KASP has great application in breeding program
Shortage of centralized service lab, poor linkage between breeding program and molecular lab limit marker application
Perspectives Perspectives
ChallengesChallenges China imports around 20% agri-products, some wheat
import is expected in the future
Wheat consumption is increasing, feed wheat reaches
15-20% depending upon price of wheat and maize
Consumers pay for quality, organic and health food
Can we produce more and better wheat with less
inputs under climate change condition?
Hybrid wheatHybrid wheat China has worked on hybrid wheat over 40 years
without significant impact on farmer field, we
need an new strategy
The implementation of Variety Protection Act
attracted more investment from private sector,
but too many varieties confused poor farmers
New technologyNew technology All leading varieties developed by conventional breeding,
marker can play a significant role in improving scab
resistance and pramiding adult plant resistance genes
Sequencing, SNP markers, GWAS, offer great potential, can
we transfer these technologies into practical breeding
GMO with significant investment in China shows a lot of
advantages, but consumer’s acceptance is a question
Conclusion and perspectivesConclusion and perspectives Chinese wheat production faces great challenge in
producing better and more with less inputs
Conventional breeding continues to play a leading role in
improving yield, climate-resilient variety can be developed
Significantly increased use of molecular markers in
breeding, KASP has great potential, and biotechnology
must be integrated into conventional breeding
AcknowledgementsAcknowledgementsX. C. Xia, X. M. Chen, Y. Yan, Y. Zhang, CAAS
Y. Zhang, A. Rasheed, Y. G. Xiao, CAAS
R. Singh, M. Reynolds, CIMMYT
W. J. Ma, R. Appels, Murdoch University
C. Morris, USDA-ARS, Pullman
Funding organizationsFunding organizations Ministry of Agriculture
Ministry of Science and Technology
National Natural Science Foundation of China
Chinese Academy of Agricultural Sciences