Synthetic wheat. an underutilized genetic resource in Nordic wheat breeding. Morten Lillemo, IPM, UMB

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1 an underutilized genetic resource in Nordic wheat breeding Morten Lillemo, IPM, UMB

2 Wheat evolution There is a huge genetic diversity in Ae. tauschii Genetic diversity of bread wheat is low, especially at the D- genome 2

3 Synthetic hexaploid wheat Durum wheat (AABB) Aegilops tauschii (DD) 3 More than 1000 lines developed at CIMMYT Synthetic hexaploid wheat (AABBDD)

4 Don t judge synthetic wheats by their phenotypes! Less than impressive in terms of agronomic characters tall, often late heading and maturing hard glumes, difficult to thresh But... Fully crossable with normal bread wheat Free-threshing types can easily be recovered already in F 2 or F 3 4

5 5 Examples of useful traits Disease resistance Karnal Bunt, Fusarium head blight, Septoria tritici leaf blotch, Stagonospora nodorum glume blotch, Helminthosporium leaf blotch, Stem rust, Leaf rust, Stripe rust, Powdery mildew etc... Abiotic stress tolerance Drought, salinity, waterlogging, heat Quality Grain softness Protein composition Pre-harvest sprouting

6 6 What about yield? Difficult to judge by the phenotype itself Many QTL studies have shown yieldenhancing QTL from wild relatives (e.g. tomato and rice) is no exception, but yield QTL are hidden in a poor agronomic phenotype... must be introgressed into adapted germplasm to be detected

7 Use of synthetic wheat at CIMMYT Limited backcross strategy highly successful Big BC 1 F 1 or BC 1 F 2 populations necessary Initial focus on disease resistance Major improvements in drought resistance 7 VOROBEY CROC_1/Ae.tauschii (224)//OPATA/3/PASTOR Biggest breakthrough in wide adaptability since the Veery s

8 Use of synthetic wheat at CIMMYT % of advanced lines in international nurseries based on synthetic wheat (rainfed wheat breeding program) 8

9 Use of synthetic wheat in Australia Synthetic backcross derived lines outperforming leading varieties by 8-30% (Ogbonnaya et al, 2007) The Synthetic-Enriched Resources for Genetic Enhancement (synerge) program (DPI, Victoria) 1. Discovering novel genetic diversity 2. Dissecting the genetic and physiological basis 3. Developing diagnostic or linked molecular markers 4. Developing introgression lines for wheat breeding 9 Targeted traits: pre-harvest sprouting, drought, salinity, CCN, yellow leaf spot

10 Success in China Used CIMMYT synthetics in breeding programs since 1995 Large kernels, high spike weight, resistance to new races of stripe rust Four synthetic-derived varieties released in Sichuan since 2003 Chuanmai 42 out-yielded commercial check variety by 23% Wuyun Yang 10 grown on > ha since 2006

11 What are we doing in Norway? 448 synthetic wheats from CIMMYT tested for powdery mildew resistance 11

12 12 s with promising partial resistance to powdery mildew Mean severity (%) across 8 environments in Norway and Switzerland: Line Name PM SYNT CROC_1/Ae.tauschii (256) 4.8 SYNT /R//W/3/F/4/RABI/5/Ae.tauschii (905) 5.7 SYNT CROC_1/Ae.tauschii (362) 6.1 SYNT GAN/Ae.tauschii (897) 6.6 SYNT CROC_1/Ae.tauschii (662) 8.0 SYNT CPI/GE/3/GO//JO69/CRA/4/Ae.tauschii (633) 8.2 SYNT ARLIN_1/Ae.tauschii (225) 8.8 SYNT SNIPE/YAV79//D/TEAL/3/Ae.tauschii (877) 10.5 SYNT GARZA/BOY//Ae.tauschii (311) 10.7 SYNT AJAIA/Ae.tauschii (330) 12.1 SYNT SCOOP_1/Ae.tauschii (662) 15.2 Check Saar 12.5 Check Naxos 11.5 Check MS Check Avocet 75.2 Lillemo et al., unpublished

13 13 Small-scale pre-breeding Lines with promising partial resistance to powdery mildew has been crossed with adapted cultivars Big space-planted BC 1 F 2 populations Phenotypic selection for PM resistance and plant type Material now in BC 1 F 4 This is great fun!

14 14 Ideas for a Nordic project Screen synthetic wheats for traits important to Nordic wheat breeding e.g. resistance to Fusarium head blight and Leaf blotch diseases Make limited backcrosses to adapted varieties breeding activity serving A jointly funded pre- Phenotypic selection breeding the activity field based serving on big space-planted breeding populations wheat breeding Output: Breeding lines with beneficial traits from the synthetic programs in the Nordic parents in adapted genetic backgrounds countries? Develop AB-QTL populations from the most promising crosses Look for yield-enhancing traits from synthetic wheat Output: Introgression lines with traits of interest and linked molecular markers for use in breeding

15 is a goldmine for wheat improvement? 15