Comparative Analyses of Chloroplast Genomes Provide Comprehensive Insights into the Adaptive Evolution of Paphiopedilum (Orchidaceae)

An elucidation of how the selection pressures caused by habitat environments affect plant plastid genomes and lead to adaptive evolution plants, is a very intense area research in evolutionary biology. The genus Paphiopedilum predominant group orchids that includes over 66 species with high horticultural ornamental value. However, owing destructive exploitation deterioration wild germplasm resources Paphiopedilum, it needs more molecular genetic studies on this genus. chloroplast cytoplasmically inherited often used studies. Thus, for study, we newly sequenced, assembled annotated five species. size these ranged from 155,886 bp (P. henryanum) 160,503 ‘GZSLKY’ Youyou) they contained 121–122 genes, which consisted 76 protein coding eight ribosomal RNAs, 37–38 transfer RNAs. Combined other 14 species, characteristics repeat sequences, divergent hotspot regions, condo usage bias were evaluated identified, respectively. gene analysis showed some fragments ndh ycf families shared both nucleus. Although genomic structure content was conserved, there significant boundary shift inverted (IR) expansion small single copy (SSC) contraction. lower GC loss genes could be result responses its unique habitats. under positive selection, including accD, matK, psbM, rpl20, rps12, ycf1, ycf2 might regarded as potential candidate further significantly contribute Paphiopedilum.