A phylogeny of Pouteria (Sapotaceae) from Malesia and Australasia

Abstract

The genus Pouteria Aublet is a pantropical group and many of its species produce high-quality timber and edible fruit. In 1991, on the basis of morphological characters, Pennington combined the genus Planchonella Pierre with Pouteria, expanding the latter genus to nine sections and 325 species. However, many Planchonella species were not included in his account and doubt remains about the generic limits of Pouteria sensu Pennington. This paper re-assesses the generic delimitation of Pouteria and its affinities with Planchonella from molecular data generated from the nuclear-encoded internal transcribed spacer (ITS) region. The analysis includes 22 Planchonella species and three Pouteria species sensu van Royen collected from Malesia and Australia, and seven additional Planchonella species from New Caledonia with molecular data available from GenBank. Other genera from Sapotaceae included in the analysis were Chrysophyllum, Niemeyera, Pichonia, Pycnandra and Xantolis (tribe Chrysophylleae) and Mimusops, Palaquium and Manilkara (outgroups from other tribes). The resulting ITS cladograms from both Bayesian and maximum parsimony analyses indicated that Malesian and Australasian Pouteria species are not monophyletic and comprise three separate lineages, therefore providing evidence against the broad circumscription of this genus by Pennington. Tertiary leaf venation type (reticulate, parallel or ramified), when mapped onto the phylogeny, correlated with these groupings, indicating that this character is taxonomically informative.