XVI International Botanical Congess

Conserved regions of the chloroplast rDNA operon containing internal transcribed spacer regions (cpITS) were amplified from various representatives of eusporangiate and leptosporangiate fern lineages. Resolution of the phylogenetic trees constructed with cpITS sequences indicate that these are quite suitable for studying phylogeny of major fern lineages. In addition to sequence information cpITS regions harbour length polymorphisms which possess a well-defined phylogenetic distribution. Both the structural pattern of length polymorphisms and sequence information are used to explore phylogenetic positions of heterosporous water ferns and basal leptosporangiate taxa.