REPETITIVE, GENOME-SPECIFIC PROBES IN WHEAT (TRITICUM-AESTIVUM) L-EM THELL AMPLIFIED WITH MINISATELLITE CORE SEQUENCES

The detection and analysis of DNA polymorphisms in crops is an essenti al component of marker-assisted selection and cultivar identification in plant breeding. We have explored the direct amplification of minisa tellite DNA by PCR (DAMD-PCR) as a means for generating DNA probes tha t are useful for detecting DNA polymorphisms and DNA fingerprinting in wheat. This technique was facilitated by high-stringency PCR with kno wn plant and animal minisatellite core sequences as primers on wheat g enomic DNA. The products of DAMD-PCR from Triticum aestivum, T. durum, T. monococcum, T. speltoides and T. tauschii showed a high degree of polymorphism and the various genomes could be identified. Cloning of t he DAMD-PCR products and subsequent Southern hybridization frequently revealed polymorphic probes showing a good degree of genome specificit y. In addition, polymorphic, single locus, and moderately dispersed PC R products were cloned that may have a potential for DNA fingerprintin g. Our experiments were limited primarily to diploid wheats and the re sults indicated that DAMD-PCR may isolate genome-specific probes from wild diploid wheat species that could be used to monitor genome introg ression into hexaploid wheat.