Mapping leaf rust resistance genes in wheat Jim Kolmer USDA-ARS Cereal Disease Laboratory Jim Anderson Univ. of Minnesota Thanks to Kun Xiao, Jen Flor

RL6149 RL6149 = Thatcher*6/T. turgidum 8404 Developed by P. Dyck RL6149 IT is ; (fleck) MRMS Thatcher x RL6149 F 2 (: - 3) 100 (3+4) 30 F 3 families 32 HR 63 Seg 25 HS

RL6149 F 3 families used for mapping 6AL location – flanked by Barc104 (13.9cm) and GWM427 (21 cm) No other Lr gene on 6AL Designated as Lr64

RL6062 RL6020 = Thatcher*6/ PI Developed by P. Dyck PI common wheat RL IT MRMS Thatcher x RL6062 F 2 (2-2 + ) 90 (3-4) 43 F 3 families 26 HR 73 SEG 36 HS Infection type F 2

RL6062 Polymorphic SSR markers not linked to resistance gene Bulk Segregation Analysis 15 HR 15 HS F 3 families 8 DArT markers on 6BL in disequilibrium – distal region SSR data Lr3 - Lr9 – linkage? RL6062 isolate specificity different P. L. Dyck

Americano 25e Uruguay landrace derived 1918 – highly resistant Tc*2/Americano 25e F 6 Adult plant resistance – no seedling resistance MRMS field resistance 0;2- adult plant IT greenhouse test Tc*3/ Americano 25e F 6 lines Three field tests – greenhouse test 1-2 genes segregating Severity (%)

Tc*3/Americano 25e F6 lines DArT 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 lines R 2 values PositionStP 2009StP 2010Crk 2010GH 1BL (Lr46 mark) B