ORGANELLAR DNA RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM (RFLP) AND NUCLEAR RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) ANALYSES OF MORPHOTYPES OF GRACILARIA (GRACILARIALES, RHODOPHYTA) FROM CHILE

The extreme phenotypic variability recognized among the species of Gra cilaria has highlighted the need for the application of refined method s to help solve taxa identifications. In Chile, there still exists unc ertainty about the exact number of Gracilaria species. Our investigati ons are centered on DNA analyses of morphotypes collected from differe nt geographical locations, namely Lenga and Isla Santa Maria, Region V III (36 degrees 00' S to 38 degrees 00' S), and Maullin, Region X (39 degrees 30' S to 43 degrees 40' S). These two regions of Chile are con sidered as areas of confluence of G. chilensis, G. verrucosa, and a sp ecies of Gracilariopsis. In this study four morphotypes, from a natura l bed located in Maullin, were analyzed for RFLP of plastid DNA and th e results compared with data of four morphotypes from a bed in Lenga. The DNA banding patterns from each enzyme digest were identical irresp ective of morphotypes and/or locations. In an attempt to unravel the n ature of the morphological differences found among Lenga and Maullin m orphotypes, RAPD analyses of nuclear DNA were also performed; however, no polymorphism has been found yet. Therefore, the data of this study , as well as concurrent data from preliminary interfertility tests, su ggest that all morphotypes belong to a single taxon, Gracilaria chilen sis.