Chromosome 7E from
Lophopyrum ponticum carries a valuable leaf rust resistant gene designated
Lr19. This gene has not been widely used in common wheat breeding because of linkage with the yellow pigment gene
Y. This gene tints flour yellow, reducing its appeal in bread making. However, a high level of yellow pigment is desirable in durum wheat breeding. We produced 97 recombinant chromosomes between
L. ponticum transfer 7D.7E#1 and its wheat homoeologues, using the
ph1b mutation that promotes homoeologous pairing. We characterized a subset of 37 of these lines with 11 molecular markers and evaluated their resistance to leaf rust and the abundance of yellow pigment. The
Lr19 gene was mapped between loci
Xwg420 and
Xmwg2062, whereas
Y was mapped distal to
Xpsr687, the most distal marker on the long arm of chromosome 7. A short terminal 7EL segment translocated to 7A, including
Lr19 and
Y (line 1-23), has been transferred to durum wheat by backcrossing. The presence of this alien segment significantly increased the abundance of yellow pigment. The
Lr19 also conferred resistance to a new durum leaf rust race from California and Mexico that is virulent on most durum wheat cultivars. The new durum lines with the recombinant 7E segment will be useful parents to increase yellow pigment and leaf rust resistance in durum wheat breeding programs. For the common wheat breeding programs, we selected the recombinant line 1-96, which has an interstitial 7E segment carrying
Lr19 but not
Y. This recombinant line can be used to improve leaf rust resistance without affecting flour color. The 7EL/7DL 1-96 recombinant chromosome did not show the meiotic self-elimination previously reported for a 7EL/7BL translocation.
Communicated by P. Langridge