Assessment of somaclonal variation in micropropagation of Damask Rose (Rosa damascena Mill.) using molecular markers

This research was performed to investigate the possible genetic change in micropropagation of Damask Rose (Rosa damascena Mill.) using start codon targeted polymorphism (SCoT) and CAAT-box derived polymorphism (CBDP) markers as gene targeted markers. The shoot single node segments included lateral buds were used as the explants. After sterilization of the explants, a solid MS medium was used for the establishment stage of explants. After 4 weeks, regenerated shoots  were subcultured in VS medium supplemented with different combinations Auxins and Cytokinins for multiplication stage. For in vitro rooting, the plantlets were subcultured in MS medium supplemented with 2 mg/L IAA(Indole AceticAcid)  and 2 mg/L IBA(Indole ButyricAcid). After 8 weeks, the rooted plants were transferred ex vitro and acclimated in the greenhouse. Start codon targeted (SCoT) and CAAT-box derived polymorphism (CBDP)markers were used for analyzing the genetic diversity of 8 Damask Rose plantlets obtained from media with  different combinations of plant growth regulators. Fifteen CBDP and fifteen SCoT primers amplified a total of 173 scorable bands, of which 74 were polymorphic. The average of polymorphic information content(PIC) for SCoT and CBDP primers were 0.32 and 0.35 respectively which revealed a good efficiency of both markers in analyzing genetic diversity. The dendrogram generated based on SCoT data separated the individuals into two groups as well as clustering based on CBDP data. Although, our findings revealed a low level of genetic variability among samples, the results of cluster analysis showed that the use of 2,4-D  in particular in higher concentrations in medium, can increase the rate of genetic changes. These results also, indicated that SCoT and CBDP techniques can be used for detection of genetic variation in in vitro cultures.