Phylogeny of the proteaceae based on atpB and atpB-rbcL intergenic spacer region sequences

Parsimony analyses were conducted for 46 genera representing all subfamilie s and tribes within Proteaceae using two chloroplast sequences: the gene at pB and the noncoding spacer region between atpB and rbcL. The spacer region was more variable than atpB and provided insertion and deletion data as we ll as nucleotide substitutions. The atpB and spacer region data sets were h ighly congruent (as indicated by the partition homogeneity test) and were a nalysed separately and combined. Both unweighted and weighted character sta tes (3:1 correction for transition bias) for the atpB data resulted in very similar strict consensus trees. In addition, the large subfamilies Proteoi deae and Grevilleoideae were analysed separately, using appropriate outgrou ps determined by the analyses with complete sampling. The results from the combination of data were better resolved and supported than the results fro m each separate data set, although the Grevilleoideae were highly unresolve d in all analyses. Most subfamilies in the Proteaceae were essentially mono phyletic, but most tribes and subtribes were not. Bellendena is weakly supp orted as the sister group to all remaining members of the Proteaceae. Monot ypic Eidotheoideae is well supported as a member of Proteoideae. Carnarvoni oideae and Sphalmioideae are strongly supported as closely allied to the Gr evilleoideae, but their positions in relation to this subfamily are unresol ved. Other unusual alliances supported by our molecular data are: Isopogon- Adenanthos-Leucadendron-Protea, Petrophile-Aulax, Cardwellia-Euplass-Gevuin a, and Opisthiolepis-Buckinghamia-Grevillea. The tree resulting from the co mbined data showed limited congruence with morphological characters (flower pairs, stylar pollen presentation, and ovule number). Congruence with chro mosome number was minimal, but our tree does support previous hypotheses of multiple aneuploidy and chromosome doubling events. The African and South American genera included in our analysis are dispersed among various clades with taxa from Australia and Asia, suggesting a former Gondwanian distribu tion for Proteaceae.