Micropropagation of Juniper (Juniperus polycarpos): Optimizing surface sterilization pretreatments can play key role in suppression of contamination and browning of shoot tip explants

Mohammad Momeni1, Ebrahim Ganji-Moghadam2*, Ahmad Asgharzadeh3, Hashem Kazemzadeh –Beneh1


The juniper (Juniperus polycarpos) is enable to growth at the extremist of the geology, climatology and hydrology condition. The emptiness seed, embryo degeneration and seed dormancy are problems which necessitate the application of biotechnological technique to propagate mentioned juniper plant in vitro. Obtaining high efficiency of surface sterilization in order to prevent explants contamination and browning is necessary to success at initiate stage of juniper micropropagation. So, the effects of formulated of hypochlorite sodium, mercury chloride and ethanol as surface sterilization treatments on shoot tip explants of juniper were investigated. Optimized surface sterilization had a significantly effect on decrease contamination and browning in shoot tip explants (P<0.01). The results showed that surface sterilization treatments inhibited microbial or fungal contamination and browning of explants which can be minimized by optimizing mercuric chloride pretreatments. The formulated duration and concentration of hypochlorite sodium not only had no appreciable suppression effect on the contamination and browning in explants but also the browning extension in culture medium like same control was accelerated. It was found that mercuric chloride sterilization had distinguish or effective more than hypochlorite sodium on decrease contamination or browning. In contrast, lowest contamination or browning in culture medium and explants was displayed by formulated mercuric chloride. Therefore, the results suggested that in tissue plants if the aim is micropropagation of Juniperus polycarpos, elimination browning or having contaminated-free plants could be get in initiate state by using optimized mercuric chloride (Ethanol 70% at 1 min- sterile distilled water (SWD)- HgCl2 0.1% at 3 min-SDW) as surface sterilization.

Keywords: Juniper; Surface sterilization; Browning; Hypochlorite sodium; Mercuric chloride