Further Optimization of Random Amplified Polymorphic DNA (RAPD) Analysis in Common Bean

Introduction The recent development of the random amplified polymorphic DNA (RAPD) marker system (Williams et al., 1990) has spawned considerable interest within the plant breeding community. The simplicity of the assay itself, as compared to restriction fragment length polymorphism (RFLP) analysis, potentially affords the opportunity to apply this marker system to the benefit of both basic and applied plant breeding problems. Since early 1991, the bean breeding and genetics program at Michigan State University has been working with the RAPD system as a means of providing molecular markers for several major disease resistance genes. Early work in our laboratory demonstrated the rapidity with which RAPD markers could be identified in common bean (Miklas ct al., 1993) and also provided useful information regarding the choice of thermostable enzyme {Stoffel Fragment DNA Polymcrasc) for use in the polymcrase chain reaction (PCR) (Miklas and Kelly, 1992). In this report we outline several modifications that we have since made to our PCR set-up and cycling profile. We believe that these modifications have not only improved our capacity for data acquisition but have improved the overall efficiency of the RAPD system in our laboratory.