Mapping leaf rust resistance genes in wheat

Jim KolmerUSDA-ARS Cereal Disease Laboratory

Jim AndersonUniv. of Minnesota

Thanks to Kun Xiao, Jen Flor

RL6149

RL6149 = Thatcher*6/T. turgidum 8404Developed by P. Dyck

RL6149 IT is ; (fleck) 20-50 MRMS

Thatcher x RL6149 F2

(: - 3) 100 (3+4) 30

F3 families

32 HR 63 Seg 25 HS

RL6149

F3 families used for mapping

6AL location – flanked by Barc104 (13.9cm) and GWM427 (21 cm)

No other Lr gene on 6AL

Designated as Lr64

RL6062RL6020 = Thatcher*6/ PI268316Developed by P. Dyck

PI268316 common wheat

RL6062 22+ IT 30-50 MRMS

Thatcher x RL6062 F2

(2-2+ ) 90 (3-4) 43

F3 families

26 HR 73 SEG 36 HS

Infection type F2

RL6062

Polymorphic SSR markers not linked to resistance gene

Bulk Segregation Analysis

15 HR 15 HS F3 families

8 DArT markers on 6BL in disequilibrium – distal region SSR data

Lr3 - Lr9 – linkage?

RL6062 isolate specificity different

P. L. Dyck - 1980

Americano 25eUruguay landrace derived1918 – highly resistant

Tc*2/Americano 25e F6

Adult plant resistance – no seedling resistance

10-20 MRMS field resistance0;2- adult plant IT greenhouse test

Tc*3/ Americano 25e F6 lines

Three field tests – greenhouse test

1-2 genes segregating

Severity (%)

Tc*3/Americano 25e F6 linesDArT map

Major effect on 1BL – likely Lr46

Select Tc*3 lines with Lr46 only

Tc*3/Americano 25e F6 lines

Smaller effect on 5B

No effect St Paul 2010 (fewer high severity lines)

Select Tc*3 lines with 5B QTL

Tc*3/Americano 25e F6 linesR2 values

Position StP 2009 StP 2010 Crk 2010 GH

1BL 26 0.254 0.293 0.392 0.379

28 (Lr46 mark)

0.257 0.303 0.382 0.409

30 0.263 0.299 0.381 0.411

32 0.265 0.292 0.373 0.408

34 0.264 0.281 0.362 0.399

36 0.259 0.266 0.346 0.386

38 0.251 0.248 0.325 0.367

5B

50 0.137 0.007 0.144 0.112

52 0.141 0.008 0.155 0.117

54 0.138 0.009 0.160 0.120

56 0.124 0.009 0.155 0.118