PERFORMANCE OF 4 NEW LEAF RUST RESISTANCE GENES TRANSFERRED TO COMMONWHEAT FROM AEGILOPS-TAUSCHII AND TRITICUM-MONOCOCCUM

The objective of this study was to test the performance of four new wh eat leaf rust resistance genes previously transferred from wild relati ves of common wheat. Leaf rust resistance gene Lr43, in wheat germplas m line KS92WGRC16, was originally from Aegilops tauschii. A second res istance gene, in line KS92WGRC23, was transferred from Triticum monoco ccum var. monococcum. Two other genes, in lines KS93U3 and KS96WGRC34, were obtained from I: monococcum var. boeoticum. In greenhouse tests, the typical low infection types produced by these lines were fleck (; ), immune (0), fleck with chlorosis (;C), and heterogeneous (X-) for K S92WGRC16, KS92WGRC23, KS96WGRC34, and KS93U3, respectively. In field tests in Kansas and Texas, KS92WGRC23 and KS92WGRC16 were highly resis tant. KS93U3 was moderately resistant in Kansas but moderately resista nt to moderately susceptible in Texas. KS96WGRC34 was moderately resis tant in Kansas but moderately resistant to susceptible in Texas. Green house adult-plant tests with race PBJL of Puccinia recondita f. sp. tr itici indicated that KS92WGRC16, KS92WGRC23, and KS96WGRC34 were highl y resistant, but KS93U3 gave a moderately resistant reaction. Growth-c hamber studies in different environments (12, 16, 20, and 24 degrees C ) showed slight temperature effects on the expression of resistance in KS96WGRC34 but not in the other lines. Tests with nine races of P. re condita f. sp. tritici indicated that only KS92WGRC16 was resistant to all the races. Races PNML and PNMQ were virulent on KS92WGRC23, and r ace TFGL was virulent on both KS93U3 and KS96WGRC34. The genes in the four germplasm lines should be used in combination with other resistan ce genes to prolong their usefulness.