| Abstract: | Rapid, simple and highly sensitive are the great advantages of RAPD (random amplified polymorphic DNA) method. However, its optimum condition of amplification varies greatly among different studies and, in turn, causes much debates in terms of its reproducibility and validation of its application to the study of systemetics. For this reason the authors tried to probe into some essential factors that might affect the result of RAPD assay. The results from the authors' genetic diversity research in Cathaya argyrophylla confirmed that (a) DNA templates, whether undergoing multiple steps of purification or not, showed the same RAPD profiles, hence, most of the steps would be unnecessary: (b) RNA, no matter deprived or not from the DNA templates, had no influence on amplification; (c) DNA templates with a wide range of concentration produced the same band patterns constantly; (d) DNA templates extracted from either fresh or dry leaves produced the same RAPD results. Therefore, it was concluded that RAPD exhibited very good reproducibility. Furthermore, the authors had also discussed some problems in product analysis and data analysis of RAPD. The use of RAPD method in taxonomic study was evaluated in the study on the relationships of congeneric species of Cimicifuga, Actaea asatica and Aconitum sungpanense, and the applicability of RAPD to systematic studies of species and closely related genera, although with some limitations, was highly appreciated. |
