Comparative genome sequence and phylogenetic analysis of chloroplast for evolutionary relationship among Pinus species

Genus Pinus is a widely dispersed genus of conifer plants in the Northern Hemisphere. However, the inadequate accessibility of genomic knowledge limits our understanding of molecular phylogeny and evolution of Pinus species. In this study, the evolutionary features of complete plastid genome and the phylogeny of the Pinus genus were studied. A total of thirteen divergent hotspot regions (trnk-UUU, matK, trnQ-UUG, atpF, atpH, rpoC1, rpoC2, rpoB, ycf2, ycf1, trnD-GUC, trnY-GUA, and trnH-GUG) were identified that would be utilized as possible genetic markers for determination of phylogeny and population genetics analysis of Pinus species. Furthermore, seven genes (petD, psaI, psaM, matK, rps18, ycf1, and ycf2) with positive selection site in Pinus species were identified. Based on the whole genome this phylogenetic study showed that twenty-four Pinus species form a significant genealogical clade. Divergence time showed that the Pinus species originated about 100 million years ago (MYA) (95% HPD, 101.76.35-109.79 MYA), in lateral stages of Cretaceous. Moreover, two of the subgenera are consequently originated in 85.05 MYA (95% HPD, 81.04-88.02 MYA). This study provides a phylogenetic relationship and a chronological framework for the future study of the molecular evolution of the Pinus species. (C) 2021 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.

Automated summary

This study investigates the evolutionary features and phylogeny of Pinus species using the complete plastid genome. Thirteen hotspot regions are identified as potential genetic markers for determining phylogeny and population genetics analysis. Seven genes with positive selection sites in Pinus species are also identified. The study reveals that Pinus species originated around 100 million years ago and two subgenera originated around 85.05 million years ago.