1. ACRCP Consultative Committee Meeting
Rust Resistance Genetics and Breeding
Barley and Oats
Australian
Cereal
Rust
Control
Program
22 March, 2012 – SARDI - Adelaide

2. Outline Progress and Update
New gene discoveries, designations and genetic studies
- BLR, BGYR and OCR
Barley back crossing and germplasm enhancement

3. Factsheet – Genetics of rust resistance to BLR
20 seedling resistance genes (Rph1-19 and Rph21) and one APR (Rph20)
Virulence detected for all genes except Rph7, Rph11, Rph14, Rph18 & Rph20
Current genetic base of resistance in Australian cultivars relies on:
Rph2, Rph3, Rph4, Rph7, Rph12, Rph19, RphCantala and Rph20

4. Factsheet – Genetics of rust resistance to BGYR
Currently poses no serious threat
Most Australian varieties are resistant to prevalent BGYR isolate
Exceptions being Clipper, Maritime, Skiff, Tantangra
Potential of posing a serious threat
Narrow genetic base of Australian varieties - based on 1-2 genes
Change in pathogen (mutation or somatic hybridization with Pst or Psh)
Basis of genetic resistance poorly understood

5. Factsheet – Genetics of rust resistance to OCR
11 oat cvs with known seedling resistance released in 1991 onwards – all now Sus
Barcoo, Bettong, Cleanleaf, Culgoa, Graza 68, Gwydir, Mula, Nugene, Taipan, Volta and Warrego
Most recommended cvs - Sus to at least one of the pts detected
Deployment of single major genes – not right breeding strategy & not working
APR sources exist in global germplasm but not utilized and characterized properly

6. Mapping of new BGYR genes AmagiNijo/WI2585
Mapped two new genes
BGYR_WI2585_1 (1HS)
BGYR_WI2585_2 (7HL)
IT 0;
Closest marker abg59
IT 1c
Closest marker abg714b

7. Mapping of new BGYR genes Galleon/HarunaNijo
Mapped one new gene
BGYR_HN_1 (1HS)
Genetic relationship of BGYR_HN_1 and BGYR_12585_1 not confirmed but likely independent based on map location
IT 0;
Closest marker awbma35

8. Mapping of new BGYR genes Yerong/Franklin
Mapped two genes
BGYR_Yerong_1 (7H)
BGYR_Franklin_2 (5H)
Genetic relationship of BGYR_Yerong_1 and BGYR_WI2585_2 both located on 7H is not clear
IT 1c
IT 0;

9. BLR Genetics
Allelic studies of WI3407/Pompadour - confirm findings of Golegaonkar et al (2010)
APR carried by two parents is conferred by same APR gene - Rph20
Additional LR APR with minor effects - detected on chromosome 2HS in WI3407
Gene on 2HS very difficult to phenotype
Dissecting region and developing single gene lines for fine mapping
APR in Ricardo – phenotypic very similar to 2HS gene in WI3407
Screening of more than 1000 lines from several international nurseries
Identified new APRs different from Rph20 (Caravela, ICB , Laura, Olbran)
Genetic studies initiated for mapping of new APRs 9

10. OCR Genetics
APR detected in range of introductions/ international nurseries
APR set (>200 genotypes) assembled for characterization and mapping
Genetics of 7 genotypes showed inheritance of 1-3 APR genes to OCR
9 SSD populations developed for mapping of new genes
AUS701348/Swan
ISR673.39/Swan
ISR673.44/Swan
ISR673.22/ISR673.8
ISR673.37/Swan
AUS701363/Swan
AUS701354/Swan
AUS701346/Swan
AUS701354/AUS701363
Excellent national and international resource for mapping and breeding 10

11. Barley backcrossing and germplasm enhancement
Backcrossing of leaf rust resistance continuing
> 10 Donors (Rph7, Rph14, Rph15, Rph16, Rph18, Rph20 and recombinant lines derived from H. vulgare x H. bulbosum crosses)
5 recurrent parents (nominated by breeders/collaborators in Qld, SA and WA)
> 100 BC3-BC5 stage are available
List/ Material will be distributed to breeding groups for choice of delivery