ibclogo XVI International Botanical Congess

Abstract Number: 5581
Session = 3.1.7


INFERENCE OF PHYLOGENETIC STATUS OF SOME COCCOID ULVOPHYCEAN GREEN ALGAE BASED ON THE ULTRASTRUCTURE AND 18SrDNA SEQUENCE DATA


Shin Watanabe~, Masaru Takano~, *Takeshi Nakayama and ^Gary L. Floyd ~Toyama Univ., Japan, *Univ. Of Tsukuba, Japan, ^Ohio State Univ., USA.


Phylogenetic analysis showed seven unicellular green algae belong to the Ulvophyceae. Their status is inferred as next. 1) A tetrad former Ignatius tetrasporus and a freshwater epiphyte Pseudocharacium americanum produce quadriflagellate zoospores with upper basal bodies shifted in the counterclockwise (CCW) and lower ones in the clockwise orientation (CW). Some of the flagellar apparatus components resemble those in swarmers of Siphonocladales. 18SrDNA sequence analysis revealed that they form a clade with the latter algae. 2) marine species, Chlorosarcinopsis halophila with biflagellate swarmers of CCW-typed basal bodies and autosporic Chlorella salina are combined to each another and included in the Ulotrichales clade. 3) A Freshwater Helicodictyon planktonicum with CCW-typed biflagellate zoospores and two Chlorella species, C. stigmatophora and C. capsulata formed a monophyletic clade but their topological position changed by different analytical methods.

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