Identification of RAPD markers tightly linked to wheat powdery mildew resistance gene Pm6.l

Pm6 transferred from Triticum timopheevii L. to common wheat, is an effective resistance gene to powdery mildew disease caused by Erysiphe graminis f. sp. tritici. The RAPD technique, employing a total of 700 decamer primers, was used to identify polymorphic markers between resistant (IGVI463) and susceptible (Prins) near-isogenic lines. Primer OPV20 produced a 2,000 base pair (bp) reproducible fragment only in the resistant near-isogenic line. The 2,000-bp DNA fragment was present in all other introgression lines containing Pm6. Using the F2 mapping population from a cross of IGVI-463 (PI170914/7*Prins) x Prins, Pm6 was shown to be closely linked to the marker OPV20-2000 at a genetic distance of 3.0 +/- 2.2 cM. The marker was successfully used in detecting the presence of Pm6 in different genetic backgrounds.