Wheat production and genetic improvement in China: progress and perspectives

1. Wheat production and genetic improvement in China: progress and perspectives Zhong-hu He Chinese Academy of Agricultural Sciences, CAAS Global Wheat Program, CIMMYT

2. Outlines • Wheat production • Progress in breeding • Marker development and application • Perspectives

3. Wheat production

4. Major crop production in China, average in 2013 and 2014

5. Unique 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

6. Chinese wheat production zones Wheat/maize rotation 75% Single wheat 5% Wheat/rice rotation 20%

7. China’s wheat production and averaged yield, 2000-2014

8. Factors 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

9. Constrains: 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

10. Constrains: 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

11. Constrains: 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%

12. Progress in breeding

13. 1-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

15. 54 10 51 9.5 y = -93.76 + 0.05 x y = -725.58 + 0.38 x 48 2 R = 0.69, P < 0.01 2 R = 0.45, P < 0.01 TGW (g) 45 9 42 Grain yield (t ha-1) 8.5 39 36 8 33 7.5 30 1980 1985 1990 1995 2000 2005 2010 1980 1985 1990 1995 2000 2005 2010 Year of release Year of release Yield potential improvement in Henan,1980-2008 Zheng et al, 2011, Field Crop Research,12: 225-233

16. B) A) Yield potential improvement in Shandong, 1970-2008 Xiao et al, 2012, Crop Science, 52:44-56

17. Synthetic derived wheat increase yield by 11.5% SD= synthetic derived, NSD = Not synthetic derived. Different letters indicate significant at 5%. Tang et al, 2014, Crop Science, 55: 98-112

18. Yield 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

19. 2- Coping with climate change • Screening for broad adaptation • Breeding for heat tolerance and water use efficiency • Planting winter wheat in spring wheat area

20. Normal planting, Oct 3, 2008 Late planting, Nov 6, 2008 Screening under different planting dates XY81 XN1376 XY81 XN1376

21. Screening for heat tolerance at plastic house

22. Winter wheat in spring wheat area, yield increase by 30%, early maturity 10 days

23. Zhongmai 175 outyielded check variety at various irrigations

24. Zhongmai 175 outyielded check variety at six different fertilizer levels

25. Summary-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

26. Molecular marker development and application

27. Approach • 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

28. Example • 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

29. 1 2 3 4 5 6 PSY-A1 1 4177 1 2 3 4 5 6 PSY-B1 1 3313 Cloned Psy genes on wheat chr 7A and 7B ZMU 32636 He et al, 2008, TAG, 116: 213-221

30. Allelic variants for the Psy-A1 gene on chr 7A Psy-A1a Psy-A1b Psy-A1c He et al, 2008, TAG, 116: 213-221

31. 194 bp 194 bp 231 bp 231 bp PCR amplification with YP7A Cultivars with high YP content Cultivars with low YP content

32. Validation of YP7A with Chinese varieties Different letters indicate significant difference at P<0.05 He et al, 2008, TAG, 116: 213-221

33. Markers 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

34. Summary of gene specific markers in wheat Liu et al, 2012, TAG, 125: 1-10

35. Marker 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

36. New varieties from MAS program CA998 CA1062 LX987 CA998 CA1062 Donor YM34/3*LX987 （Dx5、1BL/1RS） YM34/3*LX987

37. Disadvantages 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

38. 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

39. KASP 12-48 times efficient than PCR markers Manual PAGE genotyping: 2 or 3 persons KASP genotyping: 1 person 16 PCR plates (96 samples)/day 1536 genotypes/day 48 PCR plates (384/1584)/day 18,432-86,032 genotypes/day

40. Tested 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

41. Summary-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

42. Perspectives

43. Challenges • 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?

44. Hybrid 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

45. New 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

46. Conclusion 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 • Significantlyincreased use of molecular markers in breeding, KASP has great potential, and biotechnology must be integrated into conventional breeding

47. Acknowledgements X. 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

48. Funding organizations • Ministry of Agriculture • Ministry of Science and Technology • National Natural Science Foundation of China • Chinese Academy of Agricultural Sciences