花椒及其混淆品的rDNA ITS区序列分析与鉴别

目的研究不同居群的花椒及其混淆品的rDNA ITS区碱基序列的特征及其差异，为花椒的鉴别提供可靠的分子标记。方法运用PCR产物直接测序和克隆测序法对甘肃、陕西、四川、河北等7个花椒居群及3个混淆种的rDNA ITS区(包括ITS1，5.8S，ITS2)碱基序列进行序列测定。结果首次报道花椒ITS区的碱基序列，序列总长度为619-620 bp，长度变异较少，与混淆种长度仅相差4 bp。花椒各居群中，rDNA ITS区碱基序列有15个变异位点、12个信息位点、3个特异性识别位点。与混淆品间的碱基差异则较为显著，多达71个变异位点，有4个花椒特异性识别位点。结论依据花椒ITS区的序列特征可准确鉴别各居群的花椒及其混淆品；亲缘关系密切的花椒居群在地理位置上也非常靠近；rDNA ITS序列特征可作为花椒种内和种间鉴别的有效分子标记。     

基于rDNA ITS序列SNP位点的特异性聚合酶链反应引物鉴别青椒和花椒

目的设计专用于花椒与青椒鉴别的特异性聚合酶链反应(PCR)引物,建立花椒与青椒的分子鉴别方法。方法本研究提取花椒与青椒样品的DNA,并利用rDNA ITS(核糖体DNA内部转录间隔区)序列通用型引物分别对样品进行PCR扩增,PCR产物经双向测序、比对,寻找单核苷酸多态性(SNP)特异性位点,并分别针对花椒与青椒的SNP位点设计出花椒与青椒的特异性PCR引物,用于花椒与青椒的特异性PCR引物鉴别。结果所设计的特异性引物为花椒和青椒的鉴别提供了分子鉴定的依据,可以快速、准确地检测出花椒和青椒。结论本文所设计的特异性PCR引物能有效地鉴别出花椒与青椒,该方法具有准确、高效、灵敏、简便等特点,具有较好的市场应用前景。     

位点特异性PCR鉴别两面针掺伪飞龙掌血的方法研究

目的:探讨DNA条形码技术对鉴定两面针掺伪飞龙掌血的可行性，建立两面针特异性快速聚合酶链式反应(PCR)分子鉴定方法。方法:通过对两面针和伪品飞龙掌血DNA条形码进行对比分析，寻找单核苷酸多态性(SNP)位点并设计特异性鉴别引物，优化PCR反应体系与程序，进行退火温度、引物酶、反应循环数、灵敏度及专属性等方法学考察。结果:ITS2条形码适用于两面针及伪品飞龙掌血的鉴别，所建立的位点特异性PCR鉴别方法，在退火温度为56℃、循环数为33次时，伪品飞龙掌血经过特异性引物扩增后，在200～300 bp之间检出一条单一DNA条带，而两面针则无此条带。结论:所建立的位点特异性PCR方法可准确检测两面针中是否含有飞龙掌血，为两面针质量监测提供一种新型的鉴定手段。     

鼠尾草属药用植物及其近缘种的ITS序列分析

采用分子系统学方法分析鼠尾草属药用植物及其近缘种的遗传多样性，为准确进行基源鉴定、阐明本属内的种间关系及发现新的药用资源提供分子证据。本文从野外采集的27个鼠尾草属植物叶片样品中分离提取DNA，PCR扩增ITS区及5.8S rDNA完整序列并测序，采用Mega 3.1软件进行系统学分析。27个鼠尾草样品的ITS及5.8S rDNA区序列全长为612～617 bp，邻接法(neighbor-Joining)构建的系统发生树部分支持了形态学的属下划分，但对部分种的系统位置特别是三叶鼠尾草和黄花鼠尾草两个亚种的处理上与形态学划分存在明显的分歧。序列分析显示5.8S rDNA序列相当保守，而ITS区段则在亚属间差异明显，且原产我国的该属植物与欧美引进种明显具有不同起源。ITS系统树对于亚属和组的处理较为合理，但对组下的划分则表现出了信息量不足，需要其他相关证据的支持。ITS分析支持了丹参组内其他近缘种作为丹参类药材替代资源的合理性，同时也揭示了甘西鼠尾类高山丹参在遗传上与丹参类药材的显著不同。     

齿瓣石斛的位点特异性PCR鉴别

目的设计出齿瓣石斛的位点特异性鉴别引物,仅通过PCR就能完成对齿瓣石斛真伪进行准确鉴别。方法根据齿瓣石斛及其他枫斗类、黄草类石斛的rDNA ITS序列数据库,设计了齿瓣石斛的位点特异性PCR鉴别引物JB-Chiban-01S和JB-Chiban-01X。然后,对38种石斛属植物模板DNA进行了PCR扩增,阳性者即为齿瓣石斛正品。结果当退火温度设定为58℃时,只有齿瓣石斛的模板DNA能被扩增出来,而其他的37种石斛属植物均为阴性。该鉴别反应重复性好,已在鉴别齿瓣石斛时发挥重要作用。结论运用位点特异性鉴别引物能成功地对齿瓣石斛进行PCR鉴别,与DNA测序鉴别方法相比,位点特异性PCR具有高效、准确、简便、省时等优点。     

中国不同地区蛇床的rDNA ITS序列分析

目的：探讨不同分布区的蛇床Cnidium monnieri的ITS序列变异与其地理分布和化学成分的相关性。方法：设计2对引物,Pf+Pb及P5.8S ITS1+P5.8S ITS2,PCR扩增产物纯化后用银染法或ABI 310测序。结果：得到核糖体DNA中的ITS及5.8S rDNA完全序列,18S和26S rDNA部分序列,共约700 bp。5个地点样品的ITS-1及ITS-2的序列大小分别为210～217 bp和219～224 bp。ITS-1碱基序列的遗传距离0.00～1.93%,ITS-2碱基序列的遗传距离0.46～2.34%,ITS-1较为保守。以NJ法根据ITS-2序列数据重建系统发生树。哈尔滨样品聚为一组,衡水与德州样品和郑州与高淳样品各自聚为一组。结论：ITS-2序列的变异与中国产蛇床的纬度分布相关,而其与蛇床化学型的关系尚需作进一步研究。     

球花石斛的位点特异性PCR鉴别研究

为建立球花石斛的DNA分子标记鉴别方法，本文根据测定及GenBank上登录的109种共计164个石斛样本的rDNA ITS序列，设计了特异性鉴别引物QH-JB1 和QH-JB2，并对球花石斛进行了位点特异性PCR鉴别研究。结果表明，当复性条件为63.5 ℃，1 min时，只有球花石斛的模板DNA能被扩增出约300 bp的阳性扩增带，而其他种石斛均为阴性。证明用本法鉴别球花石斛简便、省时，也适用于干燥球花石斛药材的鉴别，具有广泛的应用前景。     

RNaseH依赖性PCR扩增结合熔解曲线法鉴别石菖蒲与藏菖蒲掺杂

目的 采用核糖核酸酶H依赖性PCR(rhPCR)扩增结合熔解曲线分析对石菖蒲与藏菖蒲进行快速鉴定及相互掺杂检测。方法 比对分析石菖蒲与藏菖蒲核基因组内转录间隔区2(ITS2)序列，寻找稳定的单核苷酸多态性(SNP)位点设计特异性扩增引物，根据扩增产物熔解温度(T_m)不同进行鉴别，考察引物特异性，筛选最佳混合引物比例，并考察该方法灵敏度、掺混检出限及适用性。结果 设计的特异性引物具有良好特异性，石菖蒲、藏菖蒲扩增产物可分别产生(89.4±0.2)与(87.9±0.2)℃的单一特异性熔解曲线峰。所建立的方法灵敏度高，DNA检出限均为0.1 ng,对石菖蒲和藏菖蒲的掺混检出限均为10%。检测样品28份，其中石菖蒲16份、藏菖蒲12份，检测结果与DNA条形码结果一致。结论 该研究基于RNase H依赖性PCR扩增结合熔解曲线建立的石菖蒲及藏菖蒲鉴别及掺杂检测方法可有效鉴别石菖蒲、藏菖蒲及掺杂样品，有利于石菖蒲药材质量控制。     

中日产川芎的matK、ITS基因序列及其物种间的亲缘关系

目的分析中国产川芎Ligusticum chuanxiong Hort.及日本产川芎Cnidium officinale Makino的核基因组ITS和叶绿体基因组matK序列,为探讨中日产川芎物种间的亲缘关系提供分子依据.方法采用PCR直接测序技术测定川芎和日本川芎的ITS基因和matK基因核苷酸序列并作序列变异分析.结果川芎和日本川芎的matK序列长度均为1268 bp,编码422个氨基酸.ITS1-5.8S-ITS2序列长度均为699 bp,其中18S rRNA基因3′端序列54 bp,ITS1序列215 bp,5.8S rRNA基因序列162 bp,ITS2序列222 bp,26S rRNA基因5′端序列46 bp.根据排序比较,川芎原植物与其商品药材间的matK基因和ITS基因序列完全相同,而川芎与日本川芎间matK基因则仅有1个变异位点,即在上游959 nt处1个转换替代(T→C),反映在氨基酸序列则发生一个非同义取代V(GTG)→A(GCG);ITS基因也仅有1个变异位点,即在ITS1上游54 nt处1个转换替代(T→C).结论通过进化速率较快的基因序列同源性分析,基本可以认为中日所产川芎基原一致,日本川芎学名似应改为Ligusticum chuanxiong Hort..     

多重连接探针扩增技术鉴别半夏及其常见混伪品

目的 基于多重连接探针扩增技术(MLPA)建立一种中药材半夏与其常见伪品虎掌、滴水珠的分子鉴定方法,为半夏药材质量控制提供依据。方法 从Genbank数据库下载半夏属核基因组内转录间隔区(ITS)序列,利用MEGA 6.05版软件进行序列比对,依据半夏、虎掌及滴水珠ITS序列中的单核苷酸多态性(SNP)位点设计物种特异性MLPA探针,MLPA反应后采用熔解曲线法对扩增产物进行分析。结果 半夏、虎掌和滴水珠样品DNA与物种特异性MLPA探针可分别产生位于84.84,82.76及80.14℃的单一熔解峰,表明探针具有良好特异性;构建的探针体系可对0.1 ng模板DNA进行检测,并可有效检出半夏中掺混1%的虎掌或滴水珠样品。对市场收集样品进行检测,鉴别结果准确,灵敏度高。结论 该研究建立的多重连接探针扩增方法可准确鉴别半夏和虎掌、滴水珠,具有特异性强、灵敏度高等特点,可为半夏药材质量控制提供技术支持。     

Authentication of an endangered herb <Emphasis Type="Italic">Changium smyrnioides</Emphasis> from different producing areas based on rDNA ITS sequences and allele-specific PCR

The rDNA ITS region of 18 samples of Changium smyrnioides from 7 areas and of 2 samples of Chuanminshen violaceum were sequenced and analyzed. The amplified ITS region of the samples, including a partial sequence of ITS1 and complete sequences of 5.8S and ITS2, had a total length of 555 bp. After complete alignment, there were 49 variable sites, of which 45 were informative, when gaps were treated as missing data. Samples of C. smyrnioides from different locations could be identified exactly based on the variable sites. The maximum parsimony (MP) and neighbor joining (NJ) tree constructed from the ITS sequences based on Kumar’s two-parameter model showed that the genetic distances of the C. smyrnioides samples from different locations were not always related to their geographical distances. A specific primer set for Allele-specific PCR authentication of C. violaceum from Jurong of Jiangsu was designed based on the SNP in the ITS sequence alignment. C. violaceum from the major genuine producing area in Jurong of Jiangsu could be identified exactly and quickly by Allele-specific PCR.     

Allele-specific primers for diagnostic PCR authentication of Dendrobium officinale

Based on rDNA ITS sequences of D. officinale and the other 37 species of Dendrobium, a pair of allele-specific diagnostic primers, TP-JB01S and TP-JB01X, were designed to authenticate D. officinale from the other species. Before the diagnostic PCR, the primer pair, P1 and P2, for amplifying the whole ITS region was used to validate template DNA and to obtain the appropriate template DNA for the diagnostic PCR. Diagnostic PCRs were performed using the diagnostic primers with the total DNAs of the original plants as a template. When the annealing temperature was raised to 66 degrees C, only the template DNA of D. officinale could be amplified whereas the diagnostic PCRs of the other Dendrobium species were all negative. The diagnostic PCRs have been repeated many times and have played an important role in authenticating the stems of D. officinale in China. Compared with the authentication method by sequencing DNA fragments, the allele-specific diagnostic PCR is not only simpler and time-saving but also practical and effective.     

Molecular analysis of the genus Mitragyna existing in Thailand based on rDNA ITS sequences and its application to identify a narcotic species: Mitragyna speciosa

In Thailand, there are four Mitragyna species; M. speciosa, M. hirsuta, M. diversifolia, and M. rotundifolia. One, M. speciosa, is a narcotic plant and has medicinal importance for its opium-like effect. Since the use of M. speciosa has been forbidden in Thailand, the leaves of M. diversifolia or others are frequently used as substitutes but are not considered as effective. Therefore, accurate authentication of M. speciosa is essential for both medicinal and forensic purposes. The nucleotide sequences of internal transcribed spacers (ITS) and the 5.8S coding region of nuclear ribosomal DNA (rDNA) of the Mitragyna species were analyzed. The whole length of ITS1-5.8S-ITS2 region was 608 bp in M. speciosa, 607 bp in the other species. Nineteen sites of nucleotide substitutions and 3 sites of 1-bp indels were observed, and M. speciosa showed specific sequence differed from the others. Based on the ITS sequences, a distinctive site recognized by a restriction enzyme XmaI in M. speciosa was found and then PCR-restriction fragment length polymorphism (RFLP) analysis was established to differentiate M. speciosa from the others. By the method, a 409-bp PCR fragment of ITS1-5.8S (partial) rDNA region from M. speciosa was cleaved into two fragments of 119 bp and 290 bp while the other species remained undigested. This method provides an effective and accurate identification of M. speciosa.     

Molecular authentication of the traditional Tibetan medicinal plant Swertia mussotii

Swertia mussotii is an important species in Tibetan folk medicine. However, it is quite expensive and frequently adulterated, so reliable methods for authentication of putative specimens and preparations of the species are needed to protect consumers and to support conservation measures. We show here that the chloroplast (cp) DNA RPL16 intron has limited utility for differentiating S. mussotii from closely related species, since the cpDNA RPL16 sequences are identical in S. mussotii and two other species of Swertia. However, the rDNA internal transcribed spacer (ITS) sequences differ significantly between S. mussotii and all of 13 tested potential adulterants. Thus, the ITS region provides a robust molecular marker for differentiating the medicinal S. mussotii from related adulterants. Therefore, a pair of allele-specific diagnostic primers based on the divergent ITS region was designed to distinguish S. mussotii from the other species. Authentication by allele-specific diagnostic PCR using these primers is convenient, effective and both simpler and less time-consuming than sequencing the ITS region.     

不同产地蒺藜核糖体DNA内转录间隔区序列分析

目的通过测定核糖体DNA内转录间隔区(Ribosomal DNA internal transcribed spacer,rDNA-ITS)基因序列,确定不同产地的蒺藜在种质遗传上是否存在差异。方法利用PCR产物直接测序,测定不同产地蒺藜的rDNA-ITS基因序列。结果测得ITS碱基序列742 bp,其中ITS1全部序列267 bp,5.8 S全部序列167bp,ITS2全部序列209 bp。6个产地的蒺藜样品的ITS的碱基序列完全相同。结论不同地区的蒺藜在种质上没有发生变异。     

Authentication of stems of Dendrobium officinale by rDNA ITS region sequences

The rDNA ITS regions of five Dendrobium species were sequenced. Each Dendrobium species was found to have a unique sequence in the ITS region, so that they could be easily distinguished at the DNA level. The aligned 644 bp of the ITS region includes 235 bp ITS1, 163 bp 5.8S, and 246 bp ITS2. One hundred and eighty-nine sites are variable. The sequences of D. officinale could be easily distinguished from the other four adulterant species according to the sequence variation at 11 sites, 7 in ITS1, 1 in 5.8S, and 3 in ITS2. These could be used as molecular characters to distinguish the stems of D. officinale from the adulterants.