Betaphycus, Eucheuma and Kappaphycus (Gigartinales, Florideophyceae) are the most commercially important genera of the family Solieriaceae that produce carrageenan. Here, three complete plastid genomes of Betaphycus gelatinus, Eucheuma denticulatum and Kappaphycus striatus were fully sequenced using next-generation sequencing technology. Genome organizations and gene contents of the three plastid genomes were highly alike. They all had circular mapping organizations and the sizes were 178,394 bp (B. gelatinus), 177,003 bp (E. denticulatum), and 176,763 bp (K. striatus). They encoded almost the same set of plastid genes (238–240), including 202 to 204 protein-encoding genes, 30 transfer RNA genes (tRNAs), 3 ribosomal RNA genes (rRNAs), 2 misc_RNAs (ffs, rnpB), and 1 transfer-messenger RNA gene (tmRNA). One group II intron interrupting the trnMe gene was identified in each of these three plastid genomes. Other three plastid genomes from species of the order Gigartinales including Kappaphycus alvarezii, Chondrus crispus and Mastocarpus papillatus have been reported. The plastid genome organization at the level of the order Gigartinales was highly conserved. Co-linear analysis among the six plastid genomes of the Gigartinales showed the considerable sequence synteny with the exception of one remarkable gene rearrangement. The approximately 12.5-kb gene fragment from gene psaM to ycf21 in plastid genomes of the four species of the Solieriaceae was completely reversed compared to that of M. papillatus and C. crispus. It might be used as the potential phylogenetic markers uniting the species of the Solieriaceae. In addition, phylogenetic analysis based on 138 shared protein-encoding genes from 53 Florideophyceae plastid genomes indicated all species were clearly divided into five clades corresponding to their subclasses. The results suggested there was a non-monophyletic relationship of the order Gigartinales. Four species of the family Solieriaceae formed one clade and E. denticulatum was basal relative to the other three species. The novel plastid genomes expand the available plastid pool for red algae which would facilitate the phylogenetic study in algae.

Betaphycus，麒麟菜和Kappaphycus（杉藻目，Florideophyceae）是家庭Solieriaceae产生卡拉胶的最重要的商业属。在这里，使用下一代测序技术对Betaphycus gelatinus，Eucheuma denticulatum和Kappaphycus striatus的三个完整质体基因组进行了完整测序。三个质体基因组的基因组组织和基因含量非常相似。他们都有圆形测绘组织和大小分别为178394个碱基（B. gelatinus），177003 BP（E.蟹），以及176763个碱基（K.叶蝉）。他们编码了几乎相同的质体基因集（238–240），包括202至204个蛋白质编码基因，30个转移RNA基因（tRNA），3个核糖体RNA基因（rRNA），2个misc_RNA（ffs，rnp B）和1个传递信使RNA基因（tmRNA）。在这三个质体基因组中的每一个中都鉴定出一个II类内含子，其中断了trn Me基因。来自Gigartinales物种的其他三个质体基因组，包括Kappaphycus alvarezii，Chondrus crispus和Mastocarpus papillatus已经报道。质体基因组组织在Gigartinales级的水平上是高度保守的。在Gigartinales的六个质体基因组中进行的共线性分析显示，除了一个显着的基因重排以外，该序列具有相当的序列同一性。与乳果分枝杆菌和C. crispus相比，在4种茄科植物的质体基因组中，从基因psa M到ycf 21大约12.5kb的基因片段被完全颠倒了。。它可能被用作团结茄科物种的潜在系统发生标记。此外，基于来自53个佛罗里达藻类质体基因组的138个共享蛋白质编码基因的系统发育分析表明，所有物种均清楚地分为对应其亚类的5个进化枝。结果表明，存在着一类单臂类的非单性关系。茄科的四个物种形成一个进化枝，而E. denticulatum相对于其他三个物种为基础。新的质体基因组扩展了红藻的可用质体库，这将有助于藻类的系统发育研究。