The study of plant phylogeny using amino acid sequences of Ribulose-1,5-Bisphosphate Carboxylase. V. Magnoliaceae, Polygonaceae and the concept of primitiveness

Abstract

N-terminal, 40 amino acid sequences of ribulose bisphosphate carboxylase small subunit are given for three species of Polygonaceae, three of Magnoliaceae and for Metasequoia. Making use of three plastocyanin and one cytochrome c sequences from the literature, these families are added to a previously published phylogenetic tree. Fagaceae and Proteaceae are also added. Uncertainties in the 14-family tree are pointed out. The root of the tree is identified using gymnosperm sequences. The concept of primitiveness as it is relevant to this research is discussed. From the phylogenetic tree there is no evidence for primitiveness of Magnoliaceae, though it is not precluded. Polygonaceae and Chenopodiaceae form a branch that diverges from the main tree near the presumptive dicotyledonous origin.