Campanula americana Genome sequencing

The chloroplast genome is generally conserved across angiosperms. However, several independent lineages have shown accelerated plastid genome evolution in terms of increased nucleotide substitution rates and dN/dS ratios in a subset of genes as well as structural rearrangements. A similar set of plastid genes show increased nucleotide substitution rates and dN/dS ratios across lineages, suggesting similar mechanisms may be leading to positive or relaxed purifying selection on the genes. However, whether similar mechanisms are operating at the intraspecific level is unknown. The goal of this study was to obtain and compare patterns of plastid genome interspecific divergence and intraspecific polymorphism in Campanualstrum americanum to see if there is evidence for similar accelerated plastid genome evolution acting at the intraspecific level.