Plastome Phylogenomics Provide Insight into the Evolution of Taxus

The taxonomy of an ancient gymnosperm genus Taxus, with high value in horticulture and medicine, is perplexing because few reliable morphological characters for diagnosing species. Here, we performed a comprehensive investigation the evolutionary dynamics Taxus chloroplast genomes estimated phylogenetic relationships, divergence times, ancestral distributions species by comparing 18 complete genomes. variations across genome different indicated that remarkably varied lineages have reshaped architecture. Our well-resolved phylogeny supported T. brevifolia Nutt. was basal followed other North America lineages. Divergence time estimation range reconstruction suggested originated Late Cretaceous revealed extant shared common ancestor whose distribution area probably afterwards earliest members expanded to Southeast Asia from where Chinese originated. predominant European more closer relationship Eastern Asian speciation Eurasia arose several dispersal vicariance events Miocene. Genome-wide scanning positively selected genes were involved translation photosynthesis system which might be related adaptive evolution availability these not only enhances our understanding elusive relationships such as conservation, diversity, gene selection within but also provides excellent templates genetic bases further exploration well plant breeding improvement.