Sources of potential errors in the application of random amplified polymorphic DNAs in cucumber

Abstract

The influence of tissue age, pathogen infestation, intrapopulation contamination, and polymerase chain reaction (PCR) conditions were assessed as sources of error in random amplified polymorphic DNA (RAPD) analysis. DNA from young, uninfected tissue provided the most consistent results. Plants infected with Sphaerotheca fuliginea Schl. (ex Fr.) Poll. showed variation in RAPD banding patterns compared to those of uninfected plants. Differences in banding patterns were detectable when DNA from two inbred lines were mixed at dilution ratios of ≤20:1 but not ≥50:1. Differing lots of commercially available 10× reaction buffer, MgCl2 stock solutions, and Taq DNA polymerase affected RAPD banding patterns and overall yield. For reproducibility of RAPD assays, it may be necessary to optimize reactions for specific lots of PCR reagents from either commercial or in-house sources.