Figure 5

Maximum likelihood (ML) tree based on the combined data set from rbcL and atpB genes of 138 operational taxonomic units (OTUs) (zygnematophycean algae) and five outgroup OTUs (Coleochaete) (Supplementary Tables S1, S4) using RAxML²⁶. Branch lengths are proportional to the evolutionary distances indicated by scale bar above the tree or subtree in each figure. Numbers at left and right sides above branches are bootstrap values (50% or more) by ML analysis and posterior probabilities (0.90 or more) by Bayesian inference (BI), respectively. Asterisk represents 100% bootstrap values by ML method or 1.00 posterior probability by BI. OTU designations in boldface represent 52 rbcL-types from Japan (Supplementary Table S1). Note that OTUs of I–VII correspond to those of Clades I–VII of Stancheva et al.¹¹ and “S. sp.” may belong to Temnogyra or Sirogonium because of lack of sexual reproduction characteristics. (a) Overview of the ML tree based on rbcL and atpB concatenated dataset. Details of “Desmidiales” are shown in Supplementary Fig. S5. (b) Details of part of the ML tree (a) showing Clades III–VI.