Avoiding lodging in wheat

Transcription

1 Avoiding lodging in wheat Institute of Crop Sciences Chinese Academy of Agricultural Sciences 6 th June 2017 Beijing, China Francisco J. Piñera-Chavez Pete Berry Matthew Reynolds John Foulkes Gemma Molero Siva Sukumaran

2 Background Outline Physiological breeding strategy (lodging resistance) Crop design Genetic resources and phenotyping Pre-breeding Genetic change of stem strength and root plate spread of wheat Conclusions

3 Background Yield reductions caused by lodging From 7-80% (Weibel and Pendleton 1964; Fischer and Stapper 1987; Easson et al. 1993; Tripathi et al. 2005; Acreche and Slafer 2011; Berry and Spink 2012) Incidence of lodging From 15 to 20% of the UK growing area every three years (Berry 1998; HGCA, 2005) Economic cost (severe lodging year): $188 million per year in the UK alone (Berry et al 2004)

4 Lodging Farmers field, March 2011 Selections at Toluca, September 2016 CENEB, March 2014 CENEB, March 2016 Farmers field, March 2017

5 Lodging improvements Introduction of dwarfing genes 1960 s Increased tolerance to lodging (by reducing plant height) Reduced stem growth rates more fertile florets Better response to fertilisers Plant growth regulators Further reduction of plant height Recent efforts Understanding of stem and anchorage failure mechanisms (lodging mechanistic model) Crop management (seed rate, sowing date, variety choice, nitrogen, etc.)

6 Lodging types, lodging model and key traits Root lodging Stem lodging Root plate spread Stem strength

7 Implications for lodging resistance: CIMMYT wheat breeding program as example Grain yield Yaqui Valley: o on-farm yield of 6 t ha -1 (Fischer and Edmeades 2010) o Yield potential: 10 t ha -1 (Sayre et al. 1997) Valdivia Chile: Plant height o Yield potential: 12 t ha -1 (Garcia et al. 2013) and 15.5 t ha -1 (Bustos et al. 2013) Increased from 0.9 m to 1.0 m ( ) (Aisawi et al. 2015) Wind conditions Characterization of wind gust Soil conditions Physical and mechanical properties Crop management Nitrogen, seed rate, sowing date, etc.

8 Breeding programs (molecular breeding) Physiological breeding: elite lines with increased yield potential and lodging resistance Crop design Ideotype for lodging resistance Having lodging as often as: 1 in 25 years (conservative) 1 in 10 years (accepting some lodging) Genetic resources UK and CIMMYT germplasm Including: DH populations, landraces, elite lines and synthetics Wild relative traits Phenotyping Protocols for lodging trait measurements Optimization of protocols (more rapid screening, only key traits) High-throughput tools (QTL analysis using mapping populations already available) Pre-breeding Strategic crosses to combine lodging resistance traits Selection of best germplasm Molecular markers Validation/fine mapping of QTLs Development of molecular markers

9 CROP DESIGN

10 Lodging proof plant ideotype 9.4 cm Hz 700 mm 4.77 mm Material strength 30 MPa 0.65 mm 4.94 mm 50 mm Barley Wheat 57 mm Dimensions of a lodging proof plant (Berry et al. 2007, Reynolds et al 2009)

11 Annual probability NWM wind speed characterization Stem lodging risk Wind gust return period Wind gust speed (m s -1 ) for lodging risk 0.6 (years) stem root Root lodging risk Wind gust speed (m s -1 ) NW Mexico seasonal maximum wind gust probabilities based on a 40 year spanning database Seasonal wind gust speed return period

12 GENETIC RESOURCES AND PHENOTYPING

13 Genetic resources CIMCOG (CIMMYT Mexico Core Germplasm) CIMCOG II HiBAP (High Biomass Association Panel) DH Avalon x Cadenza (subset of 84 lines) W34 x Paragon

14 Phenotyping Standard protocols described by Berry et al. (2000)

15 Ideotype target dimensions and genetic progress (Yaqui Valley) Trait Stem diameter (mm) Ideotype target Genetic range h Stem wall width (mm) Stem strength (N mm) Stem material strength (MPa) Root plate spread (mm) Height (m) Structural stem biomass (t ha -1 ) Root biomass (t ha -1 ) Best observed value Ideotype: Grain yield: 6 t ha -1 ; shoot per m 2 : 500; plants per m 2 : 200; lodge once in 25 years

16 Correlations among traits Traits Grain yield Plant height Root plate spread Root dry weight Stem diameter Stem wall width Stem DW per length Stem material strength Stem strength

17 Stem strength (N mm) Structural biomass and stem strength Dry weight per length (mg mm -1 )

18 Stem dry weight (t ha -1 ) Root dry weight (t ha -1 ) Dry matter required for support structures to avoid lodging Stem biomass Root biomass t ha -1 ; 1.0 m 6 t ha -1 ; 1.0 m 10 t ha -1 ; 0.7 m X 6 t ha -1 ; 0.7 m Lodging return period (years) Lodging return period (years)

19 Spring wheat targets for different lodging return periods Character Lodging return period (years) m tall and 6 t ha -1 Root plate spread (mm) Stem diameter (mm) Stem failure moment (N mm) (stem strength) m tall and 10 t ha -1 Root plate spread (mm) Stem diameter (mm) Stem failure moment (N mm) (stem strength) Wall width of 0.65 mm; material strength of 50 MPa

20 Model ranking Model confidence Comparison of experimental ranking and model ranking for lodging susceptibility Based on 2011 experiment s data Berry et al. (2003) Experimental ranking

21 Ideotype design for NW Mexico

22 Optimizing standard protocols

23 Optimizing standard protocols

24 QUANTITATIVE TRAIT LOCI ANALYSIS FOR LODGING-ASSOCIATED TRAITS IN WHEAT

25 Major QTLs related to lodging traits for the Avalon x Cadenza DH population Stem strength characters (blue) Root plate spread (carmine) Plant height and ear number per plant (black) Grain yield (green)

26 Summary of the QTL detected for cross-experiment means Position Additive Trait Chr QTL CI (cm) LOD PVE (%) (cm) effect a Peak marker SS 1D qss1d cfd19 3B qss3b wpt-4412 SMS 2D qsms2d BS B qsms3b BS SID 2D qsid2d BS B qsid3b cos4gb 4B qsid4b BS B qsid4b BS SIWW 3B qsiww3b BS B qsiww4b BS D qsiww4d BS D qsiww4d BS RPS 5B qrps5b BS PH 2D qph2d cos2q 3A qph3a wpt B qph3b BS D qph4d RhtMrkD1 GY 2D qgy2d BS

27 PRE-BREEDING LODGING TRAITS Male Parent VIVERO ENT Criteria Trait/units HiBAP Y Root plate spread (mm) 57 Structural rooting depth (mm) 1374 Anchorage strength (N mm) Female parents VIVERO ENT Criteria CIMCOG Plant Height (m) CIMCOG Anchorage strength (N mm) CIMCOG Stem strenght (N mm) CIMCOG Stem diameter TOTAL 4 CROSSES (a*b)

28 Root plate spread (mm) Siete cerros T66 Pavon F76 Seri M82 Bacanora T88 BRTB1*2/KIRITATI CROC_1/SQ//( )/FRET2 CIRNO Super 152 CMH79A.955/4/AGA/3/4*SN64/CNO67//I NIA66/5/NAC/6/RIALTO( PT) Borlaug 100 Stem strength (N mm)/plant height(cm) Stem strength and root plate spread (genetic change) Root plate spread Stem strength Plant height Year of release 50

29 Conclusions The ideotype has been estimated for a spring wheat crop that will lodge once in 25 years (GY = 6 t ha -1, plant height of 0.7 m, 200 plant m -2, 500 shoots m -2, SS = 268 N mm and RPS = 51 mm). Improving lodging resistance will need extra stem structural biomass which could compete with yield forming processes. The elite spring wheat assessed in this research has indicated broad genetic ranges for most of the key lodging resistance traits. Key ideotypic dimensions have not been achieved (e.g. stem strength, root plate spread). Low heritability was only identified for root plate spread. Correlations among key lodging traits indicate it is feasible to combine all the ideotypic dimensions in a single variety. Optimization of structural biomass can be difficult due to strong positive correlation between stem strength and wall width. Major QTLs on chromosomes 3B (qss3b) and 5B (qrps5b) should be validated in order to develop genetic markers for lodging resistance.

30 Acknowledgements

31 Thanks!