ATTEMPTED TRANSFER OF LEAF RUST RESISTANCE FROM TRITICUM-MONOCOCCUM AND DURUM-WHEAT TO HEXAPLOID WHEAT

An attempt was made to transfer leaf rust resistance from diploid Triticum monococcum, an autotetraploid of the T. monococcum accession, and durum cultivars Medora and Stewart to hexaploid wheat cultivars Thatcher and RL6058 (Lr34). A single gene for leaf rust resistance which was the same as Lr33 (RL6057) was transferred from the durum cultivars to hexaploid wheat. The gene transferred in crosses involving autotetraploid T. monococcum was also Lr33, but since Lr33 is on chromosome 1B, it was probably not from T. monococcum. This gene was not the same as the T. monococcum-derived gene in RL6137 (Tc(*)6/TMR5-J14-12-24). Using RL6058 (Lr34) as the recurrent parent appeared to facilitate the interspecific transfer of resistance since resistance was expressed in the first backcross generation involving RL6058 but not Thatcher.