Transition to a Land Flora: A Molecular Phylogenetic Perspective

Phylogenetic analyses of morphoultrastructural characters and DNA sequences of chloroplast, mitochondrial, and nuclear genes and investigations of genomic structural features in both organellar genomes have clarified several difficult issues in charophyte and bryophyte phylogenies. Mesostigma seems to represent the first lineage of streptophytes, and Charales are a derived member of charophytes. Liverworts and hornworts both are candidates for the basal‐most lineage in land plants according to analyses of morphoultrastructural and sequence data, but mitochondrial intron distribution favors the former. Takakia is likely a basal moss. More studies using both multigene sequence analyses and genomic structural characters will significantly improve our understanding of the origin and early evolution of land plants.