A photoautotrophic micropropagation system using large vessels with forced ventilation for commercial application

Poor growth in vitro, low survival ex vitro and intensive manual operations are commonly observed in conventional or photomixotrophic micropropagation (PM) systems using sugar-containing medium and airtight small culture vessels. To produce a large number of high-quality plantlets with simplified operation, a photoautotrophic micropropagation (PA) system using sugar-free medium and large vessels with forced ventilation has been developed and applied for commercial application. The light intensity, photoperiod, temperature and relative humidity inside of the vessels can be controlled automatically. Yucca filamentosa plantlets were cultured photoautotrophically in the PA device with a CO 2 concentration of 1000 μmol mol -1. Growth in vitro and survival percentage ex vitro of the plantlets in the PA device were compared with those of the plantlets in the PM system using sugar-containing medium and small vessels. Fresh and dry weights of the PA plantlets were significantly higher than those of the PM plantlets. Survival percentage was 96% for the PA plantlets, and 21% for the PM plantlets. The current study has proved that the rooting and acclimatization stages can be combined into one stage, and less labor and high survival percentage ex vitro can be achieved by using multi-cell trays containing a porous supporting material in the PA system. The results indicate that the PA system has advantages over the PM system for commercial application with respect to enhanced growth and high survival, and make it possible to produce high-quality plantlets rapidly.