Complete chloroplast genome of green tide algae <i>Ulva flexuosa</i> (Ulvophyceae, Chlorophyta) with comparative analysis

<div><p><i>Ulva flexuosa</i>, one kind of green tide algae, has outbroken in the Yellow Sea of China during the past ten years. In the present study, we sequenced the chloroplast genome of <i>U</i>. <i>flexuosa</i> followed by annotation and comparative analysis. It indicated that the chloroplast genomes had high conservation among <i>Ulva</i> spp., and high rearrangement outside them. Though <i>U</i>. <i>flexuosa</i> was closer to <i>U</i>. <i>linza</i> than <i>U</i>. <i>fasciata</i> in phylogenetic tree, the average Ka/Ks between <i>U</i>. <i>flexuosa</i> and <i>U</i>. <i>linza</i> assessed by 67 protein-coding genes was higher than those between <i>U</i>. <i>flexuosa</i> and other species in <i>Ulva</i> spp., due to the variation of <i>psb</i>Z, <i>psb</i>M and <i>ycf</i>20. Our results laid the foundation for the future studies on the evolution of chloroplast genomes of <i>Ulva</i>, as well as the molecular identification of <i>U</i>. <i>flexuosa</i> varieties.</p>