Wheat production and genetic improvement in China: progress and perspectives Zhong-hu He Chinese...

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