A COMBINATION OF MOLECULAR AND MORPHOLOGICAL CHARACTERS FOR DELIMITATION OF TAXA IN EUROPEAN PORELLA

The merits of morphological characters, isozyme patterns and random am plified polymorphic DNA (R.A.P.D.) markers for bryophyte species delim itation were investigated using European species of Porella. Isozymes and R.A.P.D. markers allow rapid detection of genetic differences in m orphologically highly-variable groups of organisms. Twenty-two clones of the European Porella species (eight species are currently recognise d: P. arborisvitae, P. baueri, P. canariensis, P. cordaeana, P. obtusa ta, P. pinnata, P. platyphylla, P. platyphylloidea) were investigated together with three populations of Canadian P. platyphylloidea. Isozym e patterns of esterase, glutamate-oxaloacetate transaminase, peroxidas e and malate enzyme were studied by electrophoresis. R.A.P.D. fingerpr ints were made using the polymerase chain reaction and six primers. Da ta were also obtained for 39 morphological characters scored for ten o r more individuals of each population. Eight distinct isoenzyme patter ns were obtained corresponding to the seven species and aberrant popul ation 267. These results were supported by the R.A.P.D. analysis which showed population 267 to be close to P. platyphylla but also to posse ss affinities with P. platyphylloidea. The analysis allowed a reassess ment of relationships between the European Porella species and the def inition of improved morphological character sets for discriminating th e taxa.