Genetic Improvement of Forage Crops for Climate Change Mitigation

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1 Genetic Improvement of Forage Crops for Climate Change Mitigation Michael Abberton, Athole Marshall, Mike Humphreys and James MacDuff Plant Breeding and Genetics Programme

2 Acknowledgements IBERS Animal Science Mike Theodorou Nigel Scollan Alison Kingston Smith Jon Moorby IBERS Plant Breeding and Genetics Alan Lovatt Richard Hayes Rattan Yadav Ellen Sizer Coverdale Charlotte Jones Ros Mathews Debbie Allen

3 Livestock and Grasslands Grazing plus feedcrops= 30% ice free land Meat and Milk Production Ecosystem services Environmental disbenefits: long shadow Livestock s Long Shadow FAO 2006

4 Genetic Improvement Successful Cost Effective Cumulative impact High uptake Accessible and at little or no additional cost to farmer Complementary to other approaches (management, animal breeding)

5 Greenhouse gas emissions from N fertiliser production and use Haber-Bosch process produces 100Mt artificial N/yr Emissions of 41Mt CO 2 /yr N 2 O emissions 1.25% applied N For N used to produce feedcrops for livestock: 0.2Mt/yr Soybean and pulses: 0.2M/t Forage legumes:0.2mt/yr? Also : nitrate leaching to water, ammonia emissions, energy use on farm

6 Key Requirements Increased Nitrogen Use Efficiency( NUE soilplant) Greater use of legumes BUT more efficient use of fixed N (.150kgN/ha/yr)

7 Screening systems Flowing solution culture Sand box mini swards Horizontal sand bed lysimeters Clonal 1m 2 field plots

8 NUE in sand-box swards Variation in apparent fertiliser N recovery in herbage of 94 genotypes of the amenity x forage Lolium perenne mapping family (150 kgn/ha application).

9 Nitrate interception efficiencies in horizontal sand-bed lysimeters N inflow N outflow N uptake N uptake = N inflow N outflow where N outflow is product of drainage rate from gutter and nitrate concentration in drainage - [ NO 3 ] (micromolar) Nitrate concentration gradients under contrasting Lolium x Festuca genotypes R 2 = Distance from lysimeter outflow (cm)

10 QTL for nitrate interception efficiencies in horizontal sand bed lysimeters Interception/inflow (Run 2) B R 2 = Interception/inflow (Run 3) LOD =10.4 LOD = 2.4 Proportional interception of nitrate inflow by 80 ryegrass mapping family genotypes : run 2 was conducted under bright sunlight and run 3 under overcast conditions.

11 Trifolium Red clover 14 (7) 0.67 Lotus Lotus japonicus

12 TRANSLEG Using translational genomics to underpin germplasm improvement for complex traits in crop legumes

13 Utilisation of N in the rumen Efficiency of N use <20% Differences between production systems and diets and manures etc should be seen as a valuable resource. Mismatch between needs of plant production and needs of animal Mid 1990s: 30Mt N directly deposited under extensive grazing Emissions kgN 2 O N/kg

14 Key Requirements More efficient use of N in the rumen Composition and management of excreta

15 Better use of herbage N with high sugar grass

16 Sugar content under simulated grazing (1997, mean over 5 N levels) S 23 AberDart AberAvon WSC (g/kg) Cut (Wilkins et al,, unpublished data)

17 18% higher milk protein yield and 29% less N in urine from cows fed experimental high sugar grass Performance Normal variety High Standard sugar error Milk yield (kg/day) Milk protein yield (g/day) N output in ( from Miller et al, Grass and Forage Science 56, )

18 N partitioning Diet protein (N) Milk N Urine N Faeces N Body N (muscle) Percent of diet N HS Control HS * * * Control HS * * Control Early Mid Late Stage of Lactation

19 Plant cells respond to anaerobic & heat stress in the rumen the result: excessive proteolysis Increased temperature Products of microbial metabolism Invasion by rumen micro organisms Degradation Protein turnover Synthesis Oxygen deficiency Dark Mechanical damage

20 Chromosome pairing and recombination in L. multiflorum x F. glaucescens BC 1 hybrids Preferential chromosome pairing between Lolium chromosomes 2 homologous sets of Lolium chromosomes and 7 chromosomes of Festuca

21 Half life values of leaf protein in rumen like anaerobic conditions at 39 C

22 Dietary approaches to reducing methane emissions from enteric fermentation Grazing/concentrate Digestibility, carbohydrate supply, lipids Tannins

23 Secondary compounds Condensed tannins Protein protection Reduce bloat Possible reduction in methane emissions

24 Variation in tannin content in spaced plants Bloat safe Protein protection Reduces forage intake and digestibility CT concentration (% of DM)

25 Quantifying tannin content High throughput assay developed Leaf Stem Tannin concentration (g CT/kg dry matter) Mean tannin concentration of Lotus leaf C H I A D F G E B

26 Ober Leo Georgea Norcen Terre Empire A1 0528/00 ARS 2620 Variation in leaf tannin content Upstart Steadfast Inia Draco Sunrise Viking Dawn Inbred line Al-Dewey Emlyn Lotar G Goldie Variety Tannin content (mg/g dry wt.)

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28 Research Challenges Harnessing the power of genomics for precision breeding in forages(and feeds) Understanding multifunctionality: delivering meat and milk with ecosystem services Improving our knowledge of soil plant rumensoil interfaces Optimising efficient use of fixed Nitrogen