IDENTIFICATION, MAPPING, AND APPLICATION OF POLYMORPHIC DNA ASSOCIATED WITH RESISTANCE GENE PM21 OF WHEAT

A new powdery mildew resistance gene designated Pm21, from Haynaldia v illosa, a relative of wheat, has been identified and incorporated into wheat through an alien translocation line. Cytogenetic and biochemica l analyses showed that chromosome arms 6VS and 6AL were involved in th is translocation. Random amplified polymorphic DNA (RAPD) analysis was performed on recipient wheat cultivar Yangmai 5, the translocation li ne, and H. villosa with 180 random primers. Eight of the 180 primers a mplified polymorphic DNA in the translocation line, and the same resul ts were obtained in four replications. Furthermore, RAPD analysis was reported for substitution line 6V, seven addition lines (1V-7V), and t he F-1, as well as F-2 plants of (translocation line X 'Yangmai 5'), u sing two of the eight random primers. One RAPD marker, specific to chr omosome arm 6VS, OPH17-1900, could be used as a molecular marker for t he detection of gene Pm21 in breeding materials with powdery mildew re sistance introduced from H. villosa.