| Abstract: | Gardenia jasminoides Ellis is an evergreen tropical plant and favorite to gardeners throughout the world. Several studies have documented that in vitro micropropagation can be used for clonal propagation of G. jasminoides Ellis, the efficiency remained low. In addition, no information is available on the genetic and epigenetic fidelity of the micropropagated plants. Here, we report on a simplified protocol for high efficient micropropagation of G. jasminoides Ellis cv. “Kinberly” based on enhanced branching of shoot-tips as explants. The protocol consisted of sequential use of three media, namely, bud-induction, elongation and root-induction. By using two molecular markers, amplified fragment length polymorphism (AFLP) and methylation sensitive amplified polymorphism (MSAP), we analyzed the genetic and DNA methylation pattern stability of 23 morphologically normal plants randomly taken from a sub-population (>100) of micropropagated plants originated from a single shoot-tip. We found that of >1,000 scored AFLP bands across the 23 micropropagated plants, no incident of genetic variation was detected. In contrast, of 750 scored MSAP bands, moderate but clear alteration in several DNA methylation patterns occurred in the majority of the 23 micropropagated plants. The changed methylation patterns involved both CG and CHG sites representing either hyper- or hypo-methylation, which occurred without altering the total methylation levels partly due to concomitant hyper- and hypo-methylation alterations. Our results indicated that epigenetic instability in the form of DNA methylation patterns can be susceptible to the in vitro micropropagation process for G. jasminoides Ellis, and needs to be taken into account in the process of large-scale commercial propagation of this plant. |
