| Tea is an important economic crop.The south of Shaanxi is the northernmost growth area of tea in China. There are abundance of germplasm resources and long history. However, the study and utilization of the germplasm resource were few. In this study, genetic diversity of materials were analysised,and the DNA fingerprint database of tea plant by 3 markers were built. The result showed that:1. Genetic diversity of 50 materials in Shaanxi was investigated. Taking 6 representative tea materials as templates, 40 pairs of SRAP markers were screened out from total 154 pairs of primers, which showed specific bands and highly polymorphism, and construction of DNA fingerprint database of tea plant by SRAP markers. The results demonstrated that total 338 alleles were verified using SRAP markers, and about 5-13 alleles were detected by each pair of molecular markers with an average of 8.45 alleles. And genetic polymorphism information content of each SRAP locus was between 0.78-0.99, with an average of 0.93. Additionally, the genetic similarity of the 50 varieties was between 0.49-0.69.2. Forty pairs of EST-SSR markers were screened out from total 100 pairs of primers, construction of DNA fingerprint database of tea plant by these markers. The results demonstrated that total 320 alleles were verified using EST-SSR markers, and about 3 to 16 alleles were detected by each pair of molecular markers with an average of 8 alleles. And genetic polymorphism information content of each EST-SSR locus was between 0.76~0.99, with an average of 0.94. Additionally, the genetic similarity of the 50 varieties was between 0.55~0.77.3. Thirty eight of 125 SCo T marker primers were screened out and each primer can be detected out 4 to 17 alleles. Construction of DNA fingerprint database of tea plant by SCo T markers. On average, 10.89 allelic variations were detected by each SCo T marker. Four hundred and fourteen DNA fragments were amplified via 38 pairs of SCo T primer. In addition, genetic polymorphism information content of each SCo T locus was between 0.56 and 0.98, the average of which was 0.89 for the tested materials, and the genetic similarity coefficient was between 0. 48 and 0.74.4. These markers were used in assessment of genetic diversity of 50 tea materials. And differences of the three markers in numbers of the percentage of polymorphic bands(PPB), polymorphic information content(PIC), average band informativeness(Ibav), effective multiplex ratio(EMR), resolving power(Rp), marker index(MI) were compared among these materials. The result showed that, total 336 alleles were amplified by 40 pairs of SRAP, with the PPB, PIC, EMR, Ibav, Rp, MI of 89.34%, 0.93, 7.55, 0.61, 5.11, 4.61, respectively. Meanwhile, 320 alleles were identified by 40 pairs of EST-SSR primers, and the PPB, PIC, EMR, Ibav, Rp, MI were 94.06%, 0.94, 7.53, 0.56, 4.48, 4.22, respectively. In addition, 439 alleles were detected by 38 SCo T primers, with the PPB, PIC, EMR, Ibav, Rp, MI of 96.14%, 0.89, 10.47, 0.58, 6.71, 6.07, respectively. The EMR, Rp and PIC showed similar trends among EST-SSR, SRAP and SCo T, with the highest value of SCo T, followed by SRAP and EST-SSR. However, the PIC showed different trend, with the highest value of EST-SSR, followed by SRAP and SCo T. These results indicated that SCo T markers had higher marking efficiency, and EST-SSR markers had richer polymorphism information.In summary, 50 tea plants fingerprint were construct by three markers, respectively. This research reflects the heigh genetic diversity of Shaanxi tea varieties at the molecular level, and it provides the theory foundation for the systematic breeding and cross breeding. |
PDF Full Text Request