Origin and relationships of Saintpaulia (Gesneriaceae) based on ribosomal DNA internal transcribed spacer (ITS) sequences
Origin and relationships of Saintpaulia (Gesneriaceae) based on ribosomal DNA internal transcribed spacer (ITS) sequences
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DOI：
10.2307/2446286
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发表时间：
1997-07-01
影响因子：
3
通讯作者：
Cronk, QCB
中科院分区：
文献类型：
--
作者：
Moller, M;Cronk, QCB
8种圣保利亚（Saintpaulia H. Wendl）和19种林德尔链霉（Streptocarpus Lindl）的系统发育关系。（代表了属内所有主要的生长形式），以及两个外群(Haberlea rhodopensis Friv；利用核糖体DNA的两个内部转录间隔段（ITS）的比较核苷酸序列对spadiciformis W， T. Wang进行了检测。ITS 1区长度为228 ~ 249个碱基对，ITS 2区长度为196 ~ 245个碱基对；群内和群外物种在两个间隔间的成对序列差异范围为0 ~ 29%。链状carpella不是单系的，Saintpaulia是嵌套在链状carpella亚属中。链霉亚属链霉是单系的。ITS序列数据表明，单叶状Streptocarpus物种形成了一个分支，并且在ITS 2中具有独特的47-bp缺失。结果有力地支持了(1)Saintpaulia的单系性，以及(2)Saintpaulia与Streptocarpella亚属的非洲成员的单系性，表明Saintpaulia是从Streptocarpella亚属进化而来的。花和营养性状的差异可能是由于生态适应导致了相对较快的辐射。
Phylogenetic relationships of eight species of Saintpaulia H. Wendl, 19 species of Streptocarpus Lindl. (representing all major growth forms within the genus), and two outgroups (Haberlea rhodopensis Friv., Chirita spadiciformis W, T. Wang) were examined using comparative nucleotide sequences from the two internal transcribed spacers (ITS) of nuclear ribosomal DNA. The length of the ITS 1 region ranged from 228 to 249 base pairs (bp) and the ITS 2 region from 196 to 245 bp; Pairwise sequence divergence across both spacers for ingroup and outgroup species ranged from 0 to 29%. Streptocarpus is not monophyletic, and Saintpaulia is nested within Streptocarpus subgenus Streptocarpella. Streptocarpus subgenus Streptocarpus is monophyletic. The ITS sequence data demonstrate that the unifoliate Streptocarpus species form a clade, and are also characterized by a unique 47-bp deletion in ITS 2. The results strongly support the monophyly of (1) Saintpaulia, and (2) Saintpaulia plus the African members of the subgenus Streptocarpella of Streptocarpus, The data suggest the evolution of Saintpaulia from Streptocarpus subgenus Streptocarpella. The differences in flower and vegetative characters are probably due to ecological adaptation leading to a relatively rapid radiation of Saintpaulina.