RESUMO
The random amplified polymorphic DNA (RAPD) technique was used to amplify DNA fragment, aiming at finding markers linked to the sex trait in Cycas tanqingii D. Y. Wang. A total number of 160 random primers were screened in the RAPD-PCR and more than 2500 RAPD fragments were generated from the male or the female plants. One fragment of about 500 bp was amplified steadily and repeatedly by the S0465 (CCCCGGTAAC) primer only from female plants but not male plants. The RAPD marker was then converted into female-linked dominant SCAR (Sequence Characterized Amplified Regions) marker named STQC-S465-483. The development of this sex-linked SCAR marker provides a possibility of identifying the sex of Cycas tanqingii before sexual maturation, which is very important to in situ or ex situ conservation.
Assuntos
Cycas/genética , Genes de Plantas , Marcadores Genéticos/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Processos de Determinação Sexual , Sequência de Bases , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodosRESUMO
Genetic diversity of 28 cultivars of yam (Dioscorea opposita Thunb) was assessed by means of Inter-simple sequence repeat (ISSR) markers. The results showed that seven proper primers, with rich polymorphism, could be selected from a total of forty four ISSR ones; distinct differences appeared among 28 cultivars amplified bands, and the rate of polymorphic bands was 83.01%; Shannon's Information index was 0.3191; a Jaccard's genetic similarity matrix and a dendrogram for these cultivars were formed, in which they could be divided into four groups: Group 1 was composed of D. opposita. cv. Ribenbai, D. opposita. cv. Huashanyao and D. opposita. cv. Ribenyuan; Group2 contained D. opposita. cv. Xiaoye; Group 3 contained D. opposita. cv. No.1 Songye; other 23 cultivars were put into Group4. PCA(Principal component analysis) was employed to evaluate the resolving power of the markers to differentiate among them. This laid the foundation of the identification of yam cultivars and the efficient use of its germplasm resources.
Assuntos
Dioscorea/genética , Variação Genética/genética , Repetições de Microssatélites/genética , DNA de Plantas/genética , Dioscorea/classificação , Filogenia , Reação em Cadeia da PolimeraseRESUMO
OBJECTIVE: To establish a simple rapid and sensitive nested RT-PCR method for detection of SARS coronavirus RNA by designing the specific primers for SARS and optimizing the parameters for PCR. METHODS: Primers and fluorescent probes were designed according to the sequences of SARS coronavirus genes available from GenBank. The optimization of the parameters for PCR was performed in PE 7700 thermal cycle. The 36 serum samples and 40 mouthwash of SARS patients and 80 samples of healthy people were tested. RESULTS: The positive rate of patient serum and mouthwash was 33.6%, (12/36) and 67.5%, (27/40), respectively, while the positive rate of healthy people was zero (0/160). CONCLUSION: The simple nested RT-PCR method was a rapid, efficient and sensitive one for SARS early diagnosis.
Assuntos
Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Síndrome Respiratória Aguda Grave/virologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Secreções Corporais/virologia , Primers do DNA , Humanos , RNA Viral/sangue , RNA Viral/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Síndrome Respiratória Aguda Grave/sangue , Síndrome Respiratória Aguda Grave/diagnósticoRESUMO
RAPD and ISSR markers were used to assess the germplasm genetic diversity among 10 individuals of Rehmannia glutinosa, including 8 cultivars and 2 virus-free lines micropropagated by tip tissue culture. 17 RAPD primers and 10 ISSR primers, with polymorphic and informative patterns, were selected from a total of 80 RAPD ones and 44 ISSR ones to determine these individuals' genetic diversity. The 17RAPD primers and 10 ISSR primers generated 177RAPDfragments and 110 fragments, respectively. The number of effective loci, the percentage of polymorphic loci, Shannon's Information index (I) and effective number of alleles (Ne) is in turn109, 61.58%, 0.3135, 1.3641 for RAPD makers, and 79, 71.82 %, 0.3577 and 1.4037 for ISSR markers; Jaccard's genetic similarity matrice and dendrograms for the 10 individuals were formed based on RAPD and ISSR-generated polymorphic bands. In dendrograms, they could be divided into two groups: one group containing six individuals such as Zupei 85.5, Datian 85.5, jinzhuangyuan, Jinbai, Zupei 9302 and Datian9302; the other composed of 4 ones such as Beijing No.1, Dahongpao, Dihuang 9104 and wild dihuang; the correlation coefficient of 0.649 between RAPD and ISSR markers GSs indicated that these two markers were significantly correlated. The results revealed that RAPD and ISSR markers were suitable for assessment of germplasm genetic diversity of Rehmannia glutinosa, and ISSR marker was superior to RAPD marker.
