Published online by Cambridge University Press: 05 December 2011
While only in its infancy, the application of electrophoretic analysis in studying the evolutionary biology of pteridophytes is proving to be of considerable value. Since the technique identifies subtle differences in protein structure, it can generate an improved picture of the genetic composition of organisms. To date electrophoresis is (1) providing us with new information about the structure of the pteridophyte genome, (2) interfacing well with laboratory studies of breeding system mechanisms to indicate that some pteridophytes are predominantly outcrossing species, and (3) generating genome-specific markers for detecting hybrids and analysing patterns of evolution. Electrophoretic data suggest that species of Bommeria are very distinct from one another and may not be congeneric. Further, enzyme characters indicate that the sexual Bommeria species have maintained a mechanism to promote outcrossing in populations, in spite of the limitations that this breeding system places on colonising ability. In Cystopteris, electrophoretic markers are of value in deciphering species relationships and origins, especially among neopolyploid taxa. The indication in Cystopteris that extant diploids are outcrossing may help to explain the complex systematic patterns that currently exist within and among its taxa. Further investigations may demonstrate that similar mechanisms are prevalent among other systematically challenging ferns and fern allies.