ITS2 sequence-structure phylogeny in the Scenedesmaceae with special reference to Coelastrum (Chlorophyta, Chlorophyceae), including the new genera Comasiella and Pectinodesmus
ITS2 sequence-structure phylogeny in the Scenedesmaceae with special reference to Coelastrum (Chlorophyta, Chlorophyceae), including the new genera Comasiella and Pectinodesmus
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DOI：
10.2216/09-61.1
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发表时间：
2010-07-01
期刊：
影响因子：
1.6
通讯作者：
Krienitz, Lomar
中科院分区：
文献类型：
--
作者：
Hegewald, Eberhard;Wolf, Matthias;Krienitz, Lomar
九种腔astrum类群核编码内转录间隔物2 （ITS2）核糖体RNA的序列和二级结构测定了botryoides Westella（至今卵囊科）和lunatus Dimorphococcus (scenedesmacae)，并与已有的scenedesmacae类群（Desmodesmus, Enallax, Neodesmus Scenedesmus）的GenBank条目进行了比较。系统发育分析表明，所研究的腔astrum类群分属几个不同的花腔科分支：5个腔astrum类群（小腔astrum，星腔astrum astroideum，星腔astrum变种rugosum = Coelastrum rugosum， pseudommicroporum和球形腔astrum包括proboscideum）为单系分支，2个标记为Coelastrum morum的菌株属于不同的属。带有蛇腔草的马提尼葡萄簇的非洲菌株。芬兰菌株用星形球菌、双形态球菌和哈里奥蒂娜标记morum簇。从形态上看，该菌株属于弹性体科，与赛蓬弹性体有亲缘关系。牛乳草属牛乳草科中单独的一种。Coelastrum reticulatum与Asterarcys、Dimorphococcus和Coelastrella属同属；因此，它的分离，在一个单独的属，如最初描述（Hariotina），是合理的。总体上，ITS2数据的系统发育分析表明，腔星科属于单系的scenedesmacae，因此划分为两个科是不合理的，但它们属于单系亚科腔星总科。Comasiella属和Pectinodesmus属是新建立的，并提出了几个新的组合。
Sequences and secondary structures of the nuclear-encoded internal transcribed spacer 2 (ITS2) ribosomal RNA of nine Coelastrum taxa, Asterarcys quadricellulare (Coelastraceae). Westella botryoides (hitherto Oocystaceae) and Dimorphococcus lunatus (Scenedesmaceae) were determined and compared with existing GenBank entries of scenedesmacean taxa (Desmodesmus, Enallax, Neodesmus Scenedesmus). Phylogenetic analyses showed that the studied Coelastrum taxa belong to several different lineages within the Scenedesmaceae: five Coelastrum taxa (Coelastrum microporum, Coelastrum astroideum, C. astroideum var. rugosum = Coelastrum rugosum, Coelastrum pseudomicroporum and Coelastrum sphaericum incl. Coelastrum proboscideum) form monophyletic clades, whereas two strains labeled Coelastrum morum belong to different genera. The African strain of C. martini clusters with Coelastrum cambricum. The Finnish strain labeled C. morum clusters with Asterarcys, Dimorphococcus and Hariotina. According to its morphology this strain belongs to Coelastrella, related to Coelastrella saiponensis. Westella botryoides belongs to a separate elude within the Scenedesmaceae. Coelastrum reticulatum is positioned in the chide with Asterarcys, Dimorphococcus and Coelastrella; hence its separation in a separate genus, as originally described (Hariotina), is justified. In general, the phylogenetic analysis of ITS2 data shows that the Coelastraceae are included in the monophyletic Scenedesmaceae, and thus the splitting into two families is not justified, but they belong to the monophyletic subfamily Coelastroidea. The genera Comasiella and Pectinodesmus are newly erected, and several new combinations are proposed.