A MOLECULAR PHYLOGENY OF THE HETEROKONT ALGAE BASED ON ANALYSES OF CHLOROPLAST‐ENCODED rbcL SEQUENCE DATA1

作者：Niels Daugbjerg, Robert A. Andersen · 发表于：Journal of Phycology · 年份：1997 · DOI：10.1111/j.0022-3646.1997.01031.x · 被引用次数：169 · 研究领域：Marine Biology and Ecology Research、Microbial Community Ecology and Physiology、Marine and coastal ecosystems

ABSTRACT Nearly complete ribulose‐1,5‐bisphosphate carboxylase/ oxygenase (rbcL)sequences from 27 taxa of heterokont algae were determined and combined with rbcL sequences obtained from GenBank for four other heterokont algae and three red algae. The phylogeny of the morphologically diverse haterokont algae was inferred from an unambiguously aligned data matrix using the red algae as the root, Significantly higher levels of mutational saturation in third codon positions were found when plotting the pair‐wise substitutions with and without corrections for multiple substitutions at the same site for first and second codon positions only and for third positions only. In light of this observation, third codon positions were excluded from phylogenetic analyses. Both weighted‐parsimony and maximum‐likelihood analyses supported with high bootstrap values the monophyly of the nine currently recognized classes of heterokont algae. The Eustigmatophyceae were the most basal group, and the Dictyochophyceae branched off as the second most basal group. The branching pattern for the other classes was well supported in terms of bootstrap values in the weightedparsimony analysis but was weakly supported in the maximum‐likelihood analysis (<50%). In the parsimony analysis, the diatoms formed a sister group to the branch containing the Chrysophyceae and Synurophyceae. This clade, charactetized by siliceous structures (frustules, cysts, scales), was the sister group to the Pelagophyceae/Sarcinoc...