Polyterra peat plug system for commercial-scale acclimatization of in vitro shoot cultures of hybrid aspen(Populus alba L.×P. grandidentata Michx.)

Successful acclimatization from in vitro shoot cultures of hybrid aspen were obtained using Polyterra Peat Plug System(PPPS) and Artificial Soil Mix(ASM) under two types of humidity control system such as Intermittent Misting System(IMS) and Gas Exchangeable Humidity Tent(GEHT). Best results(more than 98% survival) were observed by transplanting well-expanded(8 ㎝ in height) in vitro shoot cultures onto PPPS and maintained in the greenhouse where IMS and anti-radiation screen were installed. When acclimated plants were re-poted in round standard plastic pots containing ASM, each shoots started rapid growth with no more death. Reliable two step methods for hardening of large-scale micropropagules using this hybrid aspen was successfully demonstrated.