Phylogenetic position of Schnabelia, a genus endemic to China： Evidence from sequences of cpDNA matK gene and nrDNA ITS regions

The chloroplast gene matK and the internal transcribed spacers (ITS) of the nuclear ribosomal DNA from Schnabelia, a genus endemic to China, and 6 genera of Verbenaceae and 13 genera of Lamiaceae were sequenced. The phylogenetic signal and validity outgroups were measured and evaluated by means of the relatively apparent synapomorphy analysis (RASA). Independent and combined phylogenetic analyses for the matK and ITS sequences were performed using the maximum parsimony (MP), neighbor-joining (NJ) and maximum likelihood (ML) methods, indicating that Schnabelia oligophylla and Caryopteris terniflora form a sister-group relationship. The Caryopteris complex is not shown to be a monophyly because Trichostema, C. paniculata and C. forrestii are paraphyletic to the clade containing the remaining members of the complex. A monophyly of Ajugoideae proposed by Cantino et al., including 8 genera in this study, is strongly supported and the closest relatives of Schnabelia are in the Ajugoideae (Lamiaceae), especially near Caryopteris terniflora. The polygenetic analyses also showed that the genera of Lamiaceae and Verbenaceae sampled in this tudy are phylogenetically mixed and the genus Avicennia is distant to other genera of Verbenaceae. RASA and combined analysis can be used as effective approaches to determining the relationships among phylogenetically complex groups.     

Phylogenetic relationships and divergence times of the family Araucariaceae based on the DNA sequences of eight genes

Araucariaceae is one of the most primitive families of the living conifers, and its phylogenetic relationships and divergence times are critically important issues. The DNA sequences of 8 genes, i.e., nuclear ribosomal 18S and 26S rRNA, chloroplast 16S rRNA, rbcL, matK and rps4, and mitochondrial coxl and atpl, obtained from this study and GenBank were used for constructing the molecular phylogenetic trees of Araucariaceae, indicating that the phyiogenetic relationships among the three genera of this family should be （（Wollemia, Agathis）, Araucaria）. On the basis of the fossil calibrations of Wollemia and the two tribes Araucaria and Eutacta of the genus Araucaria, the divergence time of Araucariaceae was estimated to be （308± 53） million years ago, that is, the origin of the family was in the Late Carboniferous rather than Triassic as a traditional view. With the same gene combination, the diver- gence times of the genera Araucaria and Agathis were （246 ± 47） and （61 ±15） Ma, respectively. Statis- tical analyses on the phylogenetic trees generated by using different genes and comparisons of the divergence times estimated by using those genes suggested that the chloroplast matK and rps4 genes are most suitable for investigating the phylogenetic relationships and divergence times of the family Araucariaceae.     

Growth, structure and upconversion mechanisms of Ba2ErCl7 crystal

The methods to grow a novel upconversion crystal Ba₂ErCl₇ are reported in this note. Ba₂ErCl₇ material was synthesized with Er₂O₃, BaCl₂·2H₂O and NH₄Cl by using a so-called “direct synthesis method”. High quality Ba₂ErCl₇ single crystals with size up to 4 mm×8 mm×15 mm were grown by using the Czochralski and the Bridgman methods. Intense yellow-green luminescence was detected when the crystal was pumped by an 803 laser diode (LD). Transmittance spectrum was measured by using HITACH U-3500 spectrophotometer at room temperature for the first time, in which one can see that the transmittance is high in the range from 350 to 1 600 nm and the cut-off wavelength of the crystal was 230 nm. The upconversion mechanisms were discussed.     

Testing relative evolutionary rates and estimating divergence times among six genera of Rhizophoraceae using cpDNA and nrDNA sequences

The molecular phylogenetic trees of 10 species representing 6 genera of the family Rhizophoraceae have been constructed using the sequences of chloroplast genesmatK andrbcL as well as the ITS regions of nuclear ribosomal DNA. Relative-rate tests between lineages in these phylogenetic trees have been performed. On the basis of the results of the relative-rate tests and related molecular evolutionary rate data, the divergence times between the lineages are estimated as follows: (i) the first divergence time in these genera is 132.25 million years ago (mya); (ii) the average divergence time between two tribes, i.e. inland Legnotideae (exceptCarallia brachiata) and mangrove Rhizophoreae, is 64.13 mya; and (iii) the average divergence time between two inland species,C. garciniaefolia andC. pectinifolia, is 19.92 mya.     

红树科6属cpDNA和nrDNA序列相对速率检验及分歧时间估计

基于红树科６属１０种及外类群的ｃｐＤＮＡｍａｔＫ基因和ｒｂｃＬ基因序列以及ｎｒＤＮＡＩＴＳ区序列，分别构建了分子系统发育树，对不同系统发育树中有关分支间的核苷酸序列置换速率进行了差异显著性检验，根据相对速率检验结果，结合现有分子进化资料，推算属间的首次分枝时间为１３２．２５Ｍａ前，分布于内陆的竹节树族９除竹节树外）与分布于海红树族间的平均分歧时间为６４．１３Ｍａ前、而陆生的大叶竹节树和旁杞木间的分     

基于PCR-RFLP梨品种cpDNA遗传多态性的分析

为了研究库尔勒香梨等19个主要梨品种的cpDNA遗传多态性,采用PCR-RFLP进行分析,利用10对通用引物对总DNA进行扩增,并且采用7种限制性内切酶对PCR产物进行酶切,应用DPS v7.05版软件计算Jaccard相异系数,采用非加权类平均法(UPGMA)进行0-1系统聚类分析.结果显示:7对引物(cp01、cp02、cp03、cp04、cp06、cp09、cp10)能在梨属植物上扩增出1条特异性谱带,cp09/MvaI,cp03/Hin6I的酶切位点有显著差异.根据结果分析,库尔勒香梨与鸭梨、砀山梨、苹果梨、早酥、慈梨、金川雪梨、锦丰、新疆句句梨的平均距离系数较小,与其他梨的平均距离系数较大.     

三倍体枇杷叶绿体DNA提取方法的优化

将三倍体枇杷叶片通过液氮研磨、差速离心与蔗糖密度梯度离心相结合的方法得到高纯度的叶绿体,在光学显微镜和荧光显微镜下分别观察到椭圆形颗粒状和自发红色荧光的叶绿体.提取的cpDNA经凝胶电泳检测,完整性好,纯度高,无降解.经紫外分光光度仪测定,所得cpDNA浓度为0.761ng/ul.     

籼稻与粳稻品种间叶绿体DNA的RFLP差异

用ＥｃｏＲＩ与ＡｖａＩ对栽培稻的７个籼稻品种和４个粳稻品种进行叶绿体ＤＮＡ（ｃｐＤＮＡ）的ＲＦＬＰ分析，结果显示籼稻品种的ｃｐＤＮＡ具有较高的多态性，粳稻品种的则较为均一．另外，栽培稻的ｃｐＤＮＡ并无严格的亚种特异性．     

赤枝栲(Castanopsis kawakamii)叶绿体DNA的提纯方法研究

建立了一个快速、简便的提取赤枝榜(Castanopsis kawakamii)叶绿体DNA的方法，该方法主要步骤包括：叶绿体分离、DNA酶处理、裂解、去蛋白和纯化．本方法具有高产率、高纯度、高质量和快速简便等优点，省去了传统的蔗糖密度梯度离心和氯化铯密度梯度离心等昂贵、耗时的步骤．对获得的叶绿体DNA进行了限制性内切酶消化、RAPD分析并摸索出其最适应条件．     

栓皮栎群体cpDNA变异初步研究

对收集栓皮栎主要分布区的19个天然群体,利用PCR-RFLP技术对群体的变异进行研究.对4个cpDNA片段PCR-RFLP研究表明:19个群体间有较好的多态性,共发现9种单倍型.单倍型变异主要出现在群体间,群体内变异很小,群体间遗传分化系数(Gst)为0.8488,而群体内遗传多样性只占15.12%.栓皮栎的现有分布格局可能是第四纪冰川后,以秦岭以南的川东到大别山区一带为中心,不同的适应类型向四周逐步扩散的结果.