Development, comparability and potential applications of RAPD markers in the genus Medicago.

The aims of the current investigations were the optimization of the PCR variables for RAPD analysis in the genus Medicago and the evaluation of the reproducibility of genome specific fingerprints using this type of molecular marker. Due to the sensitivity of the polymerase chain reaction system and to the number of experimental variables, the amplification of random genomic sequences in a reproducible way was only possible with rigorously standardized reaction conditions. Several factors such as type of thermal cycler, ramping temperatures, magnesium concentration, polymerase brand and primer performance appeared to influence the obtaining of optimal DNA yields and useful electrophoretic patterns. In addition, there was evidence that, for exchanging information in collaborative research programs, the PCR conditions under which DNA polymorphisms were originally found should be closely repeated. Potential applications of RAPD markers in alfalfa improvement programs are discussed.