ABSTRACT
Background: Stevia rebaudiana Bertoni, an important anti-diabetic medicinal plant, becomes an inevitable alternative to sugar. Due to the propagation difficulties, tissue culture is the best alternative for rapid mass propagation of stevia plants
Objective: The present study was conducted to optimize a protocol for rapid micropropagation of Stevia rebaudiana by shoot tip explants and to investigate the effect of growth regulators concentration on steviol-glycosides content under in vitro culture conditions
Methods: Young nodal stem explants were collected from a young growing plant and the effects of media and growth regulators on shoot proliferation were studied. Shoots produced on optimal medium for shoot proliferation were used for rooting experiments and the effects of IBA, NAA, and active carbon on root induction in both full MS and half MS media were investigated
Results: Based on the results obtained from the proliferation stage, there was no significant difference between growth regulator levels. Analysis of data obtained from rooting experiment, revealed that there are significant differences between growth regulators in leaf length, shoot dry weight, and root fresh weight. Based on the results of mean comparison, plantlets grown on free active carbon media had the higher biomass than those grown on media supplemented with 2 mg.L[-1] active carbon. The highest content of stevioside [8.18%] was observed at half MS medium supplemented with 0.2 mg. L-1 IBA, and 2 mg.L[ -1] active carbon
Conclusion: Plant growth regulators can be included among the factors affecting shoot proliferation and root induction of Stevia rebaudiana. Micropropagation of stevia can be improved by altering the macro elements concentration and adding activated carbon. In conclusion, half MS medium supplemented with 0.2 mg.L[-1]IBA, and 2 mg.L[-1]active carbon was superior for stevioside content
ABSTRACT
Fennel [Foeniculum vulgar] is a medicinal plant species in the Apiaceae family with culinary and medicinal uses. This study was conducted to evaluate the effects of enzymatic digestion of PCR product in improvement of the efficiency of RAPD markers. Nine RAPD primers were used to amplify the genomic DNA of fifteen accessions of Fennel. Following amplification, a part of PCR products was digested with two restriction enzymes [EcoRl and MseI]. Both of digested and undigested PCR products were separated on agarose gel electrophoresis. The accessions were grouped by cluster analysis and polymorphic information content index was calculated for each marker. Also percentage and component of essential oil were indicated by CC/MS analysis. The comparison of banding patterns of digested and undigested PCR products revealed that digestion of RAPD-PCR product using a four base cutter enzyme such as Mse I shows a higher level of polymorphism as compared to standard RAPD. Cluster analysis based on data obtained by modified RAPD classified accessions more suitable as compared to standard RAPD data. There was no correlation between genetic diversity and metabolic yield. Restriction enzymes have enormous potential to improve the efficiency of RAPD markers in evaluation of genetic diversity across genome