Detection of variation among and within asparagus hybrids using random amplified DNA (RAPD) markers

The reliability of random amplified polymorphic DNA (RAPD) techniques to amplify polymorphisms in the asparagus (Asparagus officinallis L.) genome was investigated. DNA fragments generated by 10-base primers were separated on 1.5% agarose or 8% polyacrylamide gels, and the sensitivity of ethidium bromide and silver staining of amplified DNA products analysed on these gels was compared. Resolution of DNA bands on polyacrylamide gels was superior to that on agarose gels. Silver staining was more sensitive than ethidium bromide staining. The gel type used to separate DNA bands, and the staining technique used influenced the number of bands visualised for each DNA profile generated. The six asparagus cultivars used in this study were distinguished by unique banding patterns generated by each primer. OPC-12 for example generated polymorphic markers unique to three of the cultivars investigated. These markers were: ASP (500, 400, and 300 bp), TU (700 bp), and (PC 550 bp). Our investigation indicates that RAPD markers can be used to characterise asparagus cultivars, and that the technique is sensitive enough to reveal differences within seed-raised commercial cultivars. RAPD technology has the potential to detect somaclonal variation occurring during micropropagation.