Abstract Detail

From the backbone to diversification: unraveling the evolutionary history of Ericales

Phylogenetic relationships of Ericales inferred from plastid and mitochondrial genome, as well as transcriptome sequence.

Ericales is a highly morphologically heterogeneous order in the basal Asterids clade in angiosperms. It comprises 22 families, ca. 346 genera and 11,545 species, including a parasite family Mitrastemonaceae, two carnivorous families Roridulaceae and Sarraceniaceae, and a mycoheterotrophic subfamily Monotropoideae. Despite a series of molecular phylogenetic studies attempting to circumscribe some major clades of the order, some deep relationships remained unresolved, and Mitrastemonaceae has never been incorporated in phylogenetic analyses of Ericales. In this study, we obtained chloroplast genome, mitochondrial genome, and transcriptome data of representative species of all families in Ericales. Totally, the plastid genome dataset comprised 210 species with 79 protein coding genes and 162 noncoding regions, the mitochondrial genome dataset comprised 120 species with 33 protein coding genes and 8 noncoding regions, and the transcriptome dataset comprised 135 species with 1023 maximum inclusion (MI) orthologs obtained. Similar phylogenetic relationships were recovered based on plastid and mitochondrial genome datasets, and some strongly supported clades were resolved: (1) balsaminoid clade: Marcgraviaceae-(Tetrameristaceae-Balsaminaceae), was sister to the remaining families of Ericales; (2) polemonioids clade: Polemoniaceae-Fouquieriaceae; (3) primuloids clade: (Primulaceae-Ebenaceae)-Sapotaceae; (4) pentaphylacoids clade: Pentaphylacaceae-Sladeniaceae; (5) ericoids-sarracenioids clade: ((Actinidiaceae-Roridulaceae)-Sarraceniaceae)-((Ericaceae-Cyrillaceae)-Clethraceae); (6) styracoids clade: (Styracaceae-Diapensiaceae)-Symplocaceae. Theaceae was recovered as sister to styracoids clade with middle support (70%). Based on transcriptome data, the phylogenetic relationships showed some confliction. The monophyly of clades styracoid, polemonioids, pentaphylacoids, balsaminoids and ericoids-sarraceniaoids were highly supported. However, interfamily relationships in ericoids-sarraceniaoid were different. The monophyly of primuloids clade was not supported, with Sapotaceae recovered as sister to ((Theaceae-styracoids)-(ericoids-sarracenioids))-pentaphylacoids and Primulaceae-Ebenaceae sister to polemonioids. The systematic position of Mitrastemonaceae and Lecythidaceae within Ericales was not confirmed based on all the datasets. The phylogenetic confliction between organelle and nuclear genome may reveal an ancient hybrid or incomplete lineages sorting in the deep nodes. Very short internal branches of families in the phylogenetic tree indicated a rapid radiation diversification of Ericales, which posing a particularly difficult challenge for phylogenetic inference of Ericales. Some other factors that may influence the phylogenetic inference will be evaluated further, such as the impact of heterotrophic and carnivorous lineages, whole genome duplication, incomplete lineages sorting, and divergence time.

1 - Kunming Institute of Botany, 132# Lanhei Road, Kunming, Yunnan, 650201, PRC

Keywords:
phylogenomics
Ericales
genome skimming
transcriptome.

Presentation Type: Colloquium Presentations
Number: C3008
Abstract ID:156
Candidate for Awards:None