Wheat Wide Crossing

1. Essentially 2 types 1. Introgression of variation from progenitors or species with at least one common genome Normal recombination on common chromosomes Re-synthethized (synthetic) hexaploid wheat 2. Crosses with more distant relatives No recombination with wheat chromosomes Aim to develop translocations Transmission as a single unit Potential problems with linkage drag Leymusracemosus, Rye, Agropyron/Aegilops Wheat Wide Crossing

2. Priority Pre-Breeding Targets Rusts Septoria Spot blotch FHB Yield potential Water-use efficiency Rainfed and irrigated systems Nutrient-use efficiency cost saving and environmental benefit better root systems Heat tolerance

3. Synthetic hexaploid wheats Allelic variation can be recovered by going back to the wild ancestors of cultivated wheat Since the early 1990s, CIMMYT has produced over 1100 synthetic hexaploids (850 tauschiiaccns) Aimed to increase genetic diversity especially on the D-genome Now making synthetics to introduce A & B genome variation from wild and cultivated emmers. AABB DD AABBDD

4. Variation found for a large range of traits Rusts Septoriatritici Fusarium Head Blight Spot Blotch Drought tolerance Grain quality (processing) Grain nutritional quality Used in breeding at CIMMYT and distributed widely around the world Little genetic analysis initially Synthetic Hexaploids

5. Useful traits were transferred via crossing and selection to elite CIMMYT breeding lines- “derived synthetics”

6. Performance of Synthetic Derived Lines in Semi-Arid International Yield Trial (SAWYT)

8. Derived synthetics released in Spain and China (5 varieties)

9. Synth-derived lines extract more water from deeper in soil profile

10. Associations among CIMMYT elite materials genotyped with 38 SSRs Synthetic derivatives CIMMYT breeding lines or different ME World wide wheats

11. Current focus- synthetics How do we identify the best primaries for further crosses? • Direct screening for yield is difficult due to height and phenology • Screening for yield, drought and heat tolerance or components (physiological traits). • Association studies on SAWYT based on DARTs and international trial data- contribution of the D genome? • Test crosses- DH or bulked F3-F4s selected for uniform height and flowering time Breeding value • Haplotyping of synthetics with good disease resistances • Do we need to make more synthetics? • What variation do we need?

12. Current focus- synthetics How do we identify the best primaries for further crosses? • Direct screening for yield is difficult due to height and phenology • Test crosses- DH or inbreds (F3-F4s?) selected for uniform height and flowering time  Breeding value • Multiple backgrounds • Large effort so need to test theory on smaller scale first. • Test theory with existing DHs • Make selections of semidwarf, early flowering lines • Test yield performance in different environments • 5 populations- synthetic x Opata

13. Breeding Value of Primary Synthetics Synthetic x Opata Populations Opata Roelfs Height (cm) Syn 5 Syn 2 Syn 4 Syn 3 Syn 6 Syn 1 Flowering (days)

14. Breeding Value of Primary Synthetics Synthetic x Opata Populations Opata Roelfs LSD0.05= 0.89 Yield- drought Syn 5 Syn 2 Syn 4 Syn 3 Syn 6 Syn 1 LSD0.05= 1.23 Yield- full irrign

15. Current focus- synthetics Haplotyping for FHB and STB • FHB • 17 fusariumresistance markers • 71 resistantderivedsynthetics • Sumai 3 QTL 3BS in 57% lines • Wuhan QTL on 2D in 5% lines • STB • 15 markers for 14 of the 15 reported genes • 2 genes are coming from Tauschii: • Stb5 from synthetic source in low % of lines • Stb8 (coming from tauschii 219 reported in the ITMI population) in approx 50% • An indication of the presence of novel variation in many primary and derived synthetics for both STB and FHB.

16. Wheat and Rye have grown together for millenia In Afghanistan rye is ‘Gandamdora’ Wheat – Rye Introgressions “plant that infests barley or wheat” • Rye a common weed of wheat, cultivated later, further north • First deliberate interspecific wheat crosses were with rye in 1870s • Triticale • 1BL.1RS translocation • Natural wheat-rye introgressions

17. Success of 1BL.1RS translocation One translocation from Petkus rye dating to 1930s Widespread around the world Yield increase and stability Rye is a cultivated, actively bred species Yield performance Rye and triticale have a range of superior attributes cf wheat** Acid soils tolerance, drought tolerance, phosphorous-use efficiency Many introgression stocks Good foundation for simple, rapid introgression of new variation Good molecular tools** Characterization & tracking of introgressions Wheat-Rye TranslocationsWhy Rye?

18. Have 9/14 chrom arms at BC7 stage in Pavon 76 breadwheat 1RL, 1RS 2RL, 2RS 3RL, 3RS 4RL(7DS) 5RS 6RL Trials last season to assess yield potential, drought tolerance (water-use efficiency), nitrogen-use efficiency, phosphorous-use efficiency Aim for all rye chromosome arms as single translocations Smaller segments a longer term aim Wheat-Rye TranslocationsWhy Rye?

19. Rapid introgression and evaluation Elite wheat +translocation Rye X Select chrom number, presence of 3RS, recomb on 3RS 20”, 3DL.3RS 1R-7R F1 x Recomb 3RS Self 20”, 3DL.3RS (recomb) 21” Field trials

20. Leaf Rust Reaction of Pavon-Rye Translocation lines (BC7 inbreds) Sus Res

21. Yield of Pavon-Rye Translocation lines (BC7 inbreds) LSD0.05= 0.73 Yield- drought LSD0.05= 0.91 Yield- full irrign

22. Wheat and rye in mixed stands for millenia Rye a weed of wheat, cultivated later, further north Accounts of Vavilov Barbela landrace- deliberate mixture Multiple small interstitial introgressions (ISH) Present in other Landraces? Small introgression segments Greater opportunity to identify with more precise molecular tools Dispersed repeated element High density maps (SSRs, SNPs) Genomic sequencing Natural Rye Introgressions

23. 2DS.2DL.2RL(~5%) (Ribeiro-Carvalho et al 2001) 5DS + small rye terminal insert (Silva et al 1996) Unknown with small terminal insert (Ribeiro-Carvalho et al 2001) Unknown with terminal and intercalary rye segments (Ribeiro-Carvalho et al 2001) Natural Rye Introgressions • Barbela wheat landrace with rye insertions 2DL+2R • From Ribeiro-Carvalho et al 2001

24. Only small amount of the available Barbela collection sampled Good chance of finding small segments on other chromosomes in Barbela and other landraces Better molecular tools available Screening of Barbela and other landraces an important focus of future rye activities Natural Rye Introgressions • Barbela wheat landrace with rye insertions

25. Nitrogen-Use Efficiency from Leymus racemosus Other NUE mechanisms? Plant uptakeN2O Pollution (greenhouse gas) NH4+ NO2- NO3- Non-mobile Highly mobile in soil in soil BNI (Biolocical nitrification inhibition) Nitrosomonas europaea (Ammonia-oxidizing bacterium

26. NUE from L. racemosus DA: disomic addition, Dt: ditelosomic addition of L. racemosus chromosomes to/with Chinese Spring chromosomes. a Root exudate collected using 1 mM NH4Cl. b Tolerance score based on the appearance of chlorosis symptoms, where chlorosis was considered as a sign of sensitivity to assimilation of N in NHþ 4 form.

27. L. racemosus ongoing activities Field trials in Chinese Spring background • Confirm BNI in field • Compare yield performance under low and high N • Nutrient-use efficiency (N&P) • Backcrossing into better backgrounds • Generating new translocations (some in Pavon background) Markers • Define break point, retain key wheat alleles • High-throughput marker for breeding

28. Thankyou