ABSTRACT
Taxonomy is the description, naming and classification of organisms on the basis of morphology. Taxa have types that, in the case of bryophytes, are herbarium specimens. This chapter considers ways in which molecular techniques, that usually have to be used with living plant material, can improve taxonomy. It uses three molecular techniques to study speciation in liverworts. Sibling species have been found in other liverworts of the orders Marchantiales and Metzgeriales: Conocephalum conicum (L.) Dumort, Riccia dictyospora M. Howe, Pellia epiphylla (L.) Corda and Aneura pinguis (L.) Dumort. The chapter describes three examples, such as isozyme polymorphism, restriction fragment length polymorphism and random amplified polymorphic DNA. A more detailed description of the methods is provided in Bischler & Boisselier-Dubayle. Specific RFLP patterns were displayed with several restriction enzymes and hybridization with rDNA probes from wheat. Changes in the mobility of enzymes in an electric field are assumed to reflect changes in the encoding DNA.
