In Iran, a large number of Rosa species have been exposed to extinction and therefore preservation techniques are necessary to safeguard their future. In the present investigation, the objectives were to optimize the micropropagation and medium-term conservation of one of these wild species, Rosa pulverulenta. At proliferation stage, the maximum number of new leaves (9.6) were produced on the medium containing 4 μM BAP + 0 μM GA3, whereas the maximum number of axillary shoots (4.1) were observed in the medium containing 4 μM BAP + 3 μM GA3. The results for rooting experiments suggested that the highest increase in stem height (49.5 mm) at the acclimatization stage was observed in plantlets treated with 1 μM IBA + 0.5 μM NAA during the rooting stage. Comparing the refrigerator and phytotron conditions for medium-term conservation of in vitro plantlets indicated that although the refrigerator conditions resulted in lower growth rate compared with the phytotron, the survival rate in refrigerator (100%) was significantly higher than phytotron (87.5%). Furthermore, the growth rate of the plantlets from the refrigerator was accelerated during the recovery period and verged on to the ones stored in the phytotron.
in vitro conservation; micropropagation; proliferation; recovery; rooting; Rosa pulverulenta
