Complete chloroplast genome sequences of <i>Dioscorea</i>: Characterization, genomic resources, and phylogenetic analyses

Abstract

<i>Dioscorea</i> L., the largest genus of the family <i>Dioscoreaceae</i> with over 600 species, is not only an important food but also a medicinal plant. The identification and classification of <i>Dioscorea</i> L. is a rather difficult task. In this study, we sequenced five <i>Dioscorea</i> chloroplast genomes, and analyzed with four other chloroplast genomes of <i>Dioscorea</i> species from GenBank. The <i>Dioscorea</i> chloroplast genomes displayed the typical quadripartite structure of angiosperms, which consisted of a pair of inverted repeats separated by a large single-copy region, and a small single-copy region. The location and distribution of repeat sequences and microsatellites were determined, and the rapidly evolving chloroplast genome regions (<i>trnK-trnQ</i>, <i>trnS-trnG</i>, <i>trnC-petN</i>, <i>trnE-trnT</i>, <i>petG-trnW-trnP</i>, <i>ndhF</i>, <i>trnL-rpl32</i>, and <i>ycf1</i>) were detected. Phylogenetic relationships of <i>Dioscorea</i> inferred from chloroplast genomes obtained high support even in shortest internodes. Thus, chloroplast genome sequences provide potential molecular markers and genomic resources for phylogeny and species identification.