­Complete plastid genome sequences of two species of the Neotropical genus Brunellia (Brunelliaceae)

Abstract

Here we present the first two complete plastid genomes for Brunelliaceae, a Neotropical family with a single genus, Brunellia. We surveyed the entire plastid genome in order to find variable cpDNA regions for further phylogenetic analyses across the family. We sampled morphologically different species, B. antioquensis and B. trianae, and found that the plastid genomes are 157,685 and 157,775 bp in length and display the typical quadripartite structure found in angiosperms. Despite the clear morphological distinction between both species, the molecular data show a very low level of divergence. The amount of nucleotide substitutions per site is one of the lowest reported to date among published congeneric studies (π = 0.00025). The plastid genomes have gene order and content coincident with other COM (Celastrales, Oxalidales, Malpighiales) relatives. Phylogenetic analyses of selected superrosid representatives show high bootstrap support for the ((C,M)O) topology. The N-fixing clade appears as the sister group of the COM clade and Zygophyllales as the sister to the rest of the fabids group.

Comparative analysis of plastomes in Oxalidaceae: Phylogenetic relationships and potential molecular markers

“…The position of the COM clade within rosids has long been problematic in angiosperm phylogeny ( APG IV, 2016 ; Sun et al., 2016 ; Gonçalves et al., 2019 ). Our study showed that COM is monophyletic with strong support, a result that is consistent with most phylogenetic analyses based on plastid data (e.g., Gonçalves et al., 2019 ; Valencia-D et al., 2020 ) but conflicts with several studies using mitochondrial genes ( Zhu et al., 2007 ; Qiu et al., 2010 ) or nuclear data sets ( Zhao et al., 2016 ; Zeng et al., 2017 ; Yang et al., 2020 ). This phylogenetic discordance may be related to an ancient episode of hybridization followed by plastid capture during the rapid radiation of Rosidae ( Ruhfel et al., 2014 ; Sun et al., 2015 , 2016 ).…”

“…Trees tend to have lower Pi values compared with herbs ( Valencia-D et al., 2020 ). Similarly, our results showed that Pi values for both the coding and non-coding regions of the Averrhoa species were considerably lower than those of the Oxalis species ( Fig.…”

“…However, phylogenetic studies have indicated that the two families both belong to Oxalidales and are sister to each other ( APG IV, 2016 ). Oxalidales belongs to the ‘COM clade’, which also includes Celastrales and Malpighiales and has been broadly recognized as a well-defined monophyletic group ( APG IV, 2016 ; Valencia-D et al., 2020 ). Nevertheless, several recent studies based on nuclear genes suggested contradictory relationships ( Zhao et al., 2016 ; Zeng et al., 2017 ; Yang et al., 2020 ).…”

“…Nevertheless, several recent studies based on nuclear genes suggested contradictory relationships ( Zhao et al., 2016 ; Zeng et al., 2017 ; Yang et al., 2020 ). Despite support for monophyly of each of the orders within COM, the phylogenetic relationships among the orders of this group remain ambiguous ( APG IV, 2016 ; Valencia-D et al., 2020 ).…”

Incomplete lineage sorting and reticulate evolution mask species relationships in Brunelliaceae, an Andean family with rapid, recent diversification

“…and B. trianae Cuatrec.) that were putatively distantly related, morphologically divergent, and classified in different sections of the genus (Valencia et al, 2020). However, as there was low variability (99.85% sequence similarity) between those plastomes, we decided to explore the use of nuclear loci here.…”