PREDIGESTION OF DNA-TEMPLATE IMPROVES THE LEVEL OF POLYMORPHISM OF RANDOM AMPLIFIED POLYMORPHIC DNAS IN WHEAT

Random amplified polymorphic DNA (RAPD) analysis in wheat has proven t o be poor in its levels of both reproducibility and polymorphism. By d igesting the template, prior to performing PCR, with frequently cuttin g restriction enzymes, the level of polymorphism was improved. RAPD pr ofiles from certain primers were not affected by this pretreatment of the template, but other primers produced distinct profiles from each o f several restriction enzymes assayed. Some polymorphisms were specifi c to one or more restriction digests, but none involved the simple los s of bands from the unrestricted template profile. Genotypic compariso ns enabled the selection of primer-restriction enzyme combinations tha t enabled polymorphic and mappable patterns to be produced both betwee n wheat varieties and between wheats with and without chromosomal segm ents deriving from related species.