Phylogeny of basal angiosperms: Analyses of five genes from three genomes

DNA sequences of five mitochondrial, plastid, and nuclear genes from 105 sp ecies (103 genera and 63 families) representing all major lineages of gymno sperms and basal angiosperms were analyzed using parsimony methods to recon struct the phylogeny of basal angiosperms. The standard most parsimonious t rees search, taxon deletion analyses, and constraint analyses in combinatio n with Kishino-Hasegawa tests provided a rigorous analytical perspective fo r identifying Amborella, Nymphaeales, and Illiciales-Trimeniaceae-Austrobai leya (ANITA) as the basalmost lineages of extant angiosperms. The parsimony criterion (equal weighting) favored the trees in which Amborella was siste r to all other angiosperms, whereas the likelihood measure favored the tree s in which the Amborella-Nymphaeales clade represented the first diverging lineage of angiosperms. However, the Kishino-Hasegawa test showed that thes e trees, as well as those in which Nymphaeales were sister to all other ang iosperms, were not significantly different from each other. The clade of eu magnoliids, consisting of Winterales, Piperales, Magnoliales, and Laurales, was also consistently recovered in all of the analyses, albeit with low bo otstrap support. Two genera of Gnetales, Gnetum and Welwitschia, did not fo rm a sister group to angiosperms but fell into conifers with strong support . This result refutes the anthophyte hypothesis.