CHAROPHYTE EVOLUTION AND THE ORIGIN OF LAND PLANTS

Morphological, biochemical, and molecular data strongly suggest a comm on ancestry of land plants and Charophyceae sensu MATTOX & STEWART. Al though it is now widely accepted that the Charophyceae are a sister gr oup to the land plants, there is considerable disagreement over the sy stematics of different charophycean taxa and whether a Chara- or Coleo chaete-like alga was ancestral to the land plants. Comparative analyse s of complete 18S rRNA gene sequences of charophycean algae, together with sequences from bryophytes, pteridophytes and higher plants now co nfirm a common ancestry of charophytes and land plants. These data sug gest that the Charales diverged early into a separate lineage, whereas other orders within the Charophyceae show close affinities to the bry ophytes.