MOLECULAR MARKER-FACILITATED ANALYSIS OF INTROGRESSION IN WINTER-WHEAT X TRITICUM-TAUSCHII POPULATIONS

Triticum tauschii (Coss.) Schmal., a wild, diploid ancestor of common wheat (Triticum aestivum L.) has become an important genetic resource for wheat improvement. As this trend continues, a detailed understandi ng of the introgression process becomes increasingly important. This s tudy utilized molecular markers to track introgression of T. tauschii DNA into common wheat. Genotypes of 147 BC2F1 lines derived from cross es between wheat and T. tauschii were determined for one protein, 25 r estriction fragment length polymorphisms, and eight random amplified p olymorphic DNA markers. MAPMAKER and GMENDEL computer programs were us ed to determine Linkage groups and genetic distances. Map orders and r ecombination distances of linked probes compared favorably with the ex isting T. tauschii map except for chromosome 4D, which was inherited a s a unit. Certain chromosomal segments from either T. aestivum or T. t auschii were transferred more frequently than expected, and choice of recurrent parent played a role in the level of introgression that occu rred. Recombination between the D genomes of T. aestivum and T. tausch ii occurs at a level similar to that in an intraspecific cross; any ab normalities that exist should not hinder the ability to transfer genes of interest while eliminating Banking chromatin that may be responsib le for deleterious effects.