The rDNA ITS2 regions of T. dendrolimi Matsumura and T. ostriniae Pang et Chen (Hymenoptera: Trichogrammatidae) were cloned and sequenced. The homologous sequences available in GenBank were retrieved and...The rDNA ITS2 regions of T. dendrolimi Matsumura and T. ostriniae Pang et Chen (Hymenoptera: Trichogrammatidae) were cloned and sequenced. The homologous sequences available in GenBank were retrieved and analyzed, and then specific primers were designed for molecular identification and detection of T. dendrolimi. Repeated screening showed that PCR amplification by the diagnostic primers enabled the differentiation of not only bulk samples and single adult (male or female), but also eggs and juveniles, which was not possible by conventional methods. The advantage of this system over morphology based systems is that non specialists are able to identify individuals or trace specimens efficiently. The derived molecular detection technique was then used to identify 12 specimens collected from different localities on the Chinese mainland; the results showed that this protocol could be applied to molecular monitoring of Trichogramma species in the field.Finally,ITS2s of 6 geographical populations of T.dendrolimi (TdCHA,TDJL,TdXZ,TdRH,TdGZ and TdYBL) were cloned and sequenced.The multialignment analysis of intraspecific ITS2 se quences showed that the diagnostic primers have their own theoretical bases.展开更多
文摘目的:基于ITS2序列对中药材王不留行种子及其混伪品进行鉴定研究,为王不留行种子及其混伪品的鉴定提供新方法。方法:对王不留行种子及其混伪品样品提取基因组DNA、PCR扩增、双向测序获得ITS2序列。应用MEGA 6.0软件计算种内、种间遗传距离,构建邻接树,基于自行编写的代码和开源代码PHP QR Code的编码方式,将王不留行及其混伪品ITS2序列转换为条形码图片,获得各物种二维DNA条形码图片,并在中药材DNA条形码鉴定系统(www.tcmbarcode.cn)对所获得ITS2序列进行分析鉴定。结果:王不留行药材ITS2序列长度为219-221 bp,种内最大K2P遗传距离为0.009,小于其与混伪品的种间K2P遗传距离,王不留行及其混伪品ITS2序列间存在的变异位点较多。NJ树结果表明王不留行与其混伪品分别聚为一支,可明显区分。结论:ITS2序列可以准确鉴别王不留行种子,为其种质资源鉴定和中药材种子质量标准的建立提供了新方法,将获得的ITS2序列转换为二维DNA条形码可为王不留行药材流通管理提供便利,为保障王不留行临床用药安全提供了新的技术手段。
文摘The rDNA ITS2 regions of T. dendrolimi Matsumura and T. ostriniae Pang et Chen (Hymenoptera: Trichogrammatidae) were cloned and sequenced. The homologous sequences available in GenBank were retrieved and analyzed, and then specific primers were designed for molecular identification and detection of T. dendrolimi. Repeated screening showed that PCR amplification by the diagnostic primers enabled the differentiation of not only bulk samples and single adult (male or female), but also eggs and juveniles, which was not possible by conventional methods. The advantage of this system over morphology based systems is that non specialists are able to identify individuals or trace specimens efficiently. The derived molecular detection technique was then used to identify 12 specimens collected from different localities on the Chinese mainland; the results showed that this protocol could be applied to molecular monitoring of Trichogramma species in the field.Finally,ITS2s of 6 geographical populations of T.dendrolimi (TdCHA,TDJL,TdXZ,TdRH,TdGZ and TdYBL) were cloned and sequenced.The multialignment analysis of intraspecific ITS2 se quences showed that the diagnostic primers have their own theoretical bases.
