Molecular evidence for a natural primary triple hybrid in plants revealed from direct sequencing.
Molecular evidence for a natural primary triple hybrid in plants revealed from direct sequencing.
复制标题
直接测序揭示了植物中天然初级三重杂交的分子证据。
DOI：
10.1093/aob/mcm072
复制
发表时间：
2007
期刊：
影响因子：
4.2
通讯作者：
J. Fehrer
中科院分区：
文献类型：
--
作者：
Z. Kaplan;J. Fehrer
背景与目的
由三种不同植物物种组成的天然初级杂种的分子证据很少报道。因此，进行了调查的起源和一个可能的情况下，为一个不育的植物克隆的崛起，显示了三个独立的，明确定义的眼子菜属物种的诊断形态特征的组合。
方法
来自母系遗传的细胞质（rpl 20-rps 12）和双亲遗传的核核糖体DNA（ITS）的序列的组合用于鉴定推定的三重杂交体的确切身份。
关键成果
直接测序显示三个亲本类群的ITS变体，P. gramineus，P. lucens和P. perfoliatus，而叶绿体DNA鉴定P. perfoliatus为母本。描述了通过可育的双元杂种P. gramineeus x P. lucens与P. perfoliatus杂交产生三杂种的情景。
结论
尽管三交种是不育的，但它拥有一种有效的生存策略，甚至在亲本环境中也能在当地获得成功，这可能是杂种优势的结果。调查的人口是唯一一个已知的这种混合，P. x torssanderi，全世界。同工酶分析表明，殖民地遗传一致。研究的植物代表了一个似乎已经在这个网站上持续了很长一段时间的单一克隆。
BACKGROUND AND AIMS
Molecular evidence for natural primary hybrids composed of three different plant species is very rarely reported. An investigation was therefore carried out into the origin and a possible scenario for the rise of a sterile plant clone showing a combination of diagnostic morphological features of three separate, well-defined Potamogeton species.
METHODS
The combination of sequences from maternally inherited cytoplasmic (rpl20-rps12) and biparentally inherited nuclear ribosomal DNA (ITS) was used to identify the exact identity of the putative triple hybrid.
KEY RESULTS
Direct sequencing showed ITS variants of three parental taxa, P. gramineus, P. lucens and P. perfoliatus, whereas chloroplast DNA identified P. perfoliatus as the female parent. A scenario for the rise of the triple hybrid through a fertile binary hybrid P. gramineus x P. lucens crossed with P. perfoliatus is described.
CONCLUSIONS
Even though the triple hybrid is sterile, it possesses an efficient strategy for its existence and became locally successful even in the parental environment, perhaps as a result of heterosis. The population investigated is the only one known of this hybrid, P. x torssanderi, worldwide. Isozyme analysis indicated the colony to be genetically uniform. The plants studied represented a single clone that seems to have persisted at this site for a long time.