Insights into the phylogenetic relationship of the lamiids orders based on whole chloroplast genome sequencing

Abstract

Lamiids, an asterid clade consists of over 40,000 species distributed among eight orders, Icacinales, Garryales and Metteniusales, known informally as “basal lamiids”, Boraginales, Gentianales, Lamiales, Solanales, and Vahliales, known informally as “core lamiids”. Over recent years, different phylogenetic studies have clarified the formation of lamiids, however, the relationships among the orders remain unresolved. The whole chloroplast genome sequences of 49 taxa have been downloaded from GenBank (NCBI) and used to evaluate the evolutionary relationships of lamiids, and particularly to test the relationships among the main lineages of lamiids. The phylogenetic tree resulting from using Maximum Parsimony and Bayesian Inference were with identical topologies and provide good support for the following relationships, Lamiales as sister to Solanales, and Boraginales as sister to Gentianales together forming the core lamiids. In basal lamiids, the result support Garryales as sister to Metteniusales, while Icacinales was found to be the immediate sister to the other orders in the core lamiids. Our results may improve our understanding of the relationships between the orders of lamiids.

Keywords

• Basal lamiids
• Chloroplast genome
• Core lamiids
• Phylogenetic relationship
• Systematics