ABSTRACT
Objective Conserved DNA-Derived Polymorphism (CDDP) markers were used in the study of the genetic diversity of 43 Dendrobium officinale and preliminary resistance screening, in order to provide a theoretical basis for the screening of D. officinale and the selection of fine varieties. Methods A total of 21 CDDP primers were used to amplify the genomic DNA of the test material with clear and polymorphic primers. Results Sixteen primers generated 151 bands, of which 144 (95.7%) were polymorphic. The results of data analysis on three population showed that the percentage of polymorphic locus (PPL) were between 65.56% and 82.12%, coefficient of genetic differentiation among natural populations (Gst) was 0.110 2, and the total gene flow (Nm) was 4.035 4. Indicating that anthropogenic factors may also promote the genetic diversity of D. officinale. Conclusion The genetic diversity of D. officinale was rich, and the results showed that there were eight plants with potentially good resistance among 43 materials.
ABSTRACT
Objective: To optimize the regeneration system of Rhodiola crenulata, to establish the optimal conditions for resistance screening, and to lay the foundation for the establishment of the efficient genetic transformation system of R. crenulata. Methods: The leaves of Rhodiola crenulata were used as explants. The influences of different ratios of 6-BA, NAA, and IAA in the medium on callus induction and growth conditions were observed, and the implant resistance of Kanamycin (Kan) and hygromycin (Hyg) was screened by gradient method. Results: MS + 3.0 mg/L 6-BA + 1.0 mg/L NAA + 700 mg/L L-Pro was the optimal medium for the differentiation of leaf adventitious bud and the differentiation ratio of adventitious bud reached 92%; MS + 700 mg/L L-Pro was the medium for adventitious roots; The best selection of genetic transformation system for R. crenulata was 200 mg/L Kan and 10 mg/L Hyg; Adding 10 mg/L Vc could effectively inhibit the phenolic substances secretion. Conclusion: The regeneration system of R. crenulata, is optimized, and the pressure of Kan and Hyg for genetic transformation system of R. crenulata is screened.
ABSTRACT
A method of streptomycin resistance screening was applied to improve t he productivity of Natamycin by Streptomyces gilvosporeus(ATCC13326) The sp ores treated with UV light were regenerated on agar plates containing 0 6?g/mL stre p tomycin 122 streptomycin resistant(str) mutants were obtained The Natamycin y iel ds of 13 mutants were higher than the original strain The mutants with high Na t amycin productivity were screened at a high frequency(10 6%) The highest one that demonstrated 1 46 times that of the original strain in Natamy cin productivity was obtained