绿绒蒿属藏药植物ndhF和rbcL序列片段特征分析

应用叶绿体ndhF和rbcL序列对绿绒蒿属藏药植物欧贝:长叶绿绒蒿Meconopsis lancifolia、全缘叶绿绒蒿Meconopsis integrifolia、红花绿绒蒿Meconopsis punicea、尼泊尔绿绒蒿Meconopsis napaulensis;刺儿恩:总状绿绒蒿Meconopsis racemosa、多刺绿绒蒿Meconopsis horridula进行鉴别,对其序列特征差异和亲缘关系进行分析。PCR直接测序后获得六种绿绒蒿的rbcL和ndhF的部分序列。用Clustal X2.1和MEGA6.06等软件分析得到任意两种间均有变异位点和遗传距离,根据rbcL和ndhF基因部分序列数据分别建立系统树。rbcL序列分析显示,任意两种间有变异位点;ndhF序列分析显示,除总状绿绒蒿(居群1)和多刺绿绒蒿序列无明显差异外,其他任意两种间均有位点变异。根据叶绿体ndhF和rbcL基因序列数据可以很好的鉴别6种绿绒蒿属藏药植物。

大黄属(蓼科)植物ndhF基因的适应性进化(英文)

大黄属(Rheum L.)是蓼科(Polygonaceae)中一个高度分化的大属,广泛分布在亚洲和欧洲的高山和沙漠地区,全世界约60种,其中在青藏高原及其邻近地区发现了约40种。该属种的高度分化曾被推测是第三纪末青藏高原的快速隆升以及第四纪气候的反复变化所引发的适应性辐射导致。为进一步了解大黄属植物辐射式物种分化的分子适应机制,该研究选取34个形态上多样化的大黄属物种,利用系统发育分析软件,在时间框架下采用位点模型和分支模型对大黄属的叶绿体ndhF基因进行了适应性进化分析。结果表明:大黄属植物的分子进化系统树呈现短而平行的辐射式分支式样,显示出典型的物种快速辐射多样化特征;用位点模型检验ndhF基因是否存在经受正向选择(ω>1)时,在氨基酸水平上共鉴定出3个NDHF亚基的正选择位点(188H,465H,551L),对NDHF亚基的二级结构进行分析后发现编码的188H氨基酸位于α螺旋上。大黄属植物可能通过这些结构域的适应性进化,适应青藏高原的快速隆升以及第四纪气候的反复变化而引发的陆地生态系统改变。该研究结果可为今后对该属植物的实验分析提供首选位点。

Phylogenetic inferences in Prunus （Rosaceae） using chloroplast ndhF and nuclear ribosomal ITS sequences

Sequences of the chloroplast ndhF gene and the nuclear ribosomal ITS regions are employed to recon-struct the phylogeny of Prunus (Rosaceae), and evaluate the classification schemes of this genus. The two data sets are congruent in that the genera Prunus s.l. and Maddenia form a monophyletic group, with Maddenia nested within Prunus. However, the ndhF data set is incongruent with the ITS data supporting two major groups within Prunus: one consisting of subgenera Laurocerasus (including Pygeum) and Padus as well as the genus Maddenia and another of subgenera Amygdalus, Cerasus, and Prunus. The ITS data, on the other hand, support a clade composed of subgenera Amygdalus and Prunus and Prunus sect. Microcerasus in addition to a paraphyletic grade of subgenera Laurocerasus and Padus (and the genus Maddenia) taxa. In general, the subgeneric classifications of Prunus s.l. are not supported. The ITS and ndhF phylogenies differ mainly in interspecific relationships and the relative position of the Padus/Laurocerasus group. Both ITS and ndhF data sets suggest that the formerly recog-nized genus Pygeum is polyphyletic and that the distinction of the subgenera Padus and Laurocerasus is not supported. The biogeographic interactions of the temperate and tropical members in the Padus/Laurocera- sus/Maddenia alliance including Pygeum are shown to be highly dynamic and complex.

Phylogeny of Catalpa （Bignoniaceae） inferred from sequences of chloroplast ndhF and nuclear ribosomal DNA

Phylogenetics of Chilopsis and Catalpa (Bignoniaceae) was elucidated based on sequences of chloro-plast ndhF and the nrDNA ITS region. In Bignoniaceae, Chilopsis and Catalpa are most closely related as sister genera. Our data supported section Macrocatalpa of the West Indies and section Catalpa of eastern Asian and North American continents. Within section Catalpa, Catalpa ovata of eastern Asia form a clade with North American species, C. speciosa and C. bignonioides, while the other eastern Asian species comprise a clade where C. duclouxii is sister to the clade of C. bungei and C. fargesii. The Caribbean species of Catalpa diverged early from the continental species. More studies are needed to test whether the phylogenetic pattern is common in eastern Asian-North American disjunct genera with species in the West Indies.

银杏叶绿体ndhF RNA编辑现象分析及C290位编辑对胁迫处理的响应

RNA编辑是一种转录后修饰加工过程,通过碱基的插入、缺失或替换可改变氨基酸的种类,增加蛋白质的疏水性和同源蛋白在不同物种间的保守性。该文通过DNA与cDNA序列的比对,分析了裸子植物银杏(Ginkgobiloba)叶绿体功能基因ndhF的编辑现象,该基因共含有21个编辑位点,且这21个位点均为部分编辑。生物信息学分析及与其它物种比对结果表明,ndhFC290位编辑可能会影响该蛋白的正确折叠。进一步使用单克隆酶切方法测定了不同胁迫处理对ndhFC290位编辑效率的影响,结果表明该位点的编辑效率对温度和黑暗敏感。

Phylogenetics and biogeography of eastern Asian–North American disjunct genus Pachysandra (Buxaceae) inferred from nucleotide sequences

Pachysandra is an eastern Asian-North American disjtunct genus with three species, two in eastern Asia （Pachysandra axillaris and Pachysandra terminalis） and one in eastern North America （Pachysandra procurnbens）. Although morphological and cytological studies suggest a close affinity of Pprocumbens with P axillaris, molecular data from nuclear and chloroplast DNA regions have provided conflicting signals. In this study, we tested previous phylogenetic hypotheses using sequences of nuclear ribosomal DNA internal transcribed spacers and chloroplast ndhF gene from multiple individuals of each of the three species. We also estimated the time of divergence between eastem Asia and eastern North America. Our results support the morphological and cytological conclusion that P procumbens is more closely related to P axillaris than to P terminalis. The estimated time of divergence of P axillaris and P procumbens was 14.6±5.5 mya, consistent with estimates from many other eastern Asian-North American disjunct genera. The migration of Pachysandra populations from eastern Asia to North America might have occurred by way of the North Atlantic land bridge.

DNA条形码在检疫性杂草银毛龙葵鉴定中的应用研究

银毛龙葵是我国进境植物检疫性有害生物,到目前为止我国还没有关于银毛龙葵的分子检测方法。本研究收集26份茄属植物样品,包括银毛龙葵5个不同来源的个体以及它的15个近缘种,使用了3个DNA区段trnS-trnG、ndhF和waxy来探讨银毛龙葵的DNA条形码检测方法。研究结果显示银毛龙葵从其近缘种中被成功鉴定出;此外trnS-trnG、ndhF和waxy 3个片段由于具有较强的分辨力而被建议作为茄属植物补充条形码。该研究对于银毛龙葵及其他茄属植物的检疫和监测具有重要价值。

一品红亚属杂草DNA条形码的筛选研究

为筛选可用于一品红亚属植物鉴定的DNA条形码序列,通过比较ITS、ITS2、trn H-psb A、rbc L、ndh F的种内和种间变异,进行Barcoding gap检验和鉴定成功率分析。结果表明:ITS、ITS2和trn H-psb A的种内种间变异数据显示明显好于rbc L、ndh F。在Barcoding gap检验和鉴定效率分析方面,trn H-psb A明显好于其他4个区域,但该区域也存在一些明显的缺点。而ITS2与ndh F的组合序列,明显好于其单条序列,有望成为一品红亚属植物DNA条形码序列。