PART OF A SPECIAL ISSUE ON PALM BIOLOGY Phylogenetic utility of the nuclear genes AGAMOUS 1 and PHYTOCHROME B in palms (Arecaceae): an example within Bactridinae

†Background and Aims Molecular phylogenetic studies of palms (Arecaceae) have not yet provided a fullyresolved phylogeny of the family. There is a need to increase the current set of markers to resolve difficultgroups such as the Neotropical subtribe Bactridinae (Arecoideae: Cocoseae). We propose the use of twosingle-copy nuclear genes as valuable tools for palm phylogenetics.†Methods New primers were developed for the amplification of the AGAMOUS 1 (AG1) and PHYTOCHROME B(PHYB) genes. For the AGAMOUS gene, the paralogue 1 of Elaeis guineensis (EgAG1) was targeted. The regionamplified contained coding sequences between the MIKC K and C MADS-box domains. For the PHYB gene,exon 1 (partial sequence) was first amplified in palm species using published degenerate primers for Poaceae,and then specific palm primers were designed. The two gene portions were sequenced in 22 species of palms repre-senting all genera of Bactridinae, with emphasis on Astrocaryum and Hexopetion, the status of the latter genus stillbeing debated.†Key Results The new primers designed allow consistent amplification and high-quality sequencing within thepalm family. The two loci studied produced more variability than chloroplast loci and equally or less variabilitythan PRK, RPBII and ITS nuclear markers. The phylogenetic structure obtained with AG1 and PHYB genes pro-vides new insights into intergeneric relationships within the Bactridinae and the intrageneric structure ofAstrocaryum. The Hexopetion clade was recovered as monophyletic with both markers and was weakly supportedas sister to Astrocaryum sensu stricto in the combined analysis. The rare Astrocaryum minus formed a speciescomplex with Astrocaryum gynacanthum. Moreover, both AG1 and PHYB contain a microsatellite that couldhave further uses in species delimitation and population genetics.†Conclusions AG1 and PHYB provide additional phylogenetic information within the palm family, and shouldprove useful in combination with other genes to improve the resolution of palm phylogenies.Key words: AGAMOUS 1, PHYTOCHROME B, phylogenetic markers, microsatellite, palms, Arecaceae,Bactridinae, Acrocomia, Aiphanes, Astrocaryum, Bactris, Desmoncus, Hexopetion.