A rooting matrix and tissue culture vessel system yielded larger, faster growing Echeveria plants

Echeveria 'Black Prince' was micropropagated in a modified MS medium gelled with agar or liquid-infused OASIS foam growing medium cultured in square rigid polycarbonate boxes (Magenta-type vessels) and cultured in OASIS foam enclosed in flexible film vessels, (non-vented, 2 vented, and 4 vented with microporus membranes). After four weeks of culture, plantlets in flexible bags spent 1 week in a greenhouse mist bed to acclimatize the in vitro material to sunlight while rigid box treatments remained in the laboratory. After 5 weeks plants were potted in soilless mix and hand-watered as necessary. The plants from agar in box had the lowest survival compared to plants from the OASIS foam treatments (84 vs. 90-97%, respectively). Plants from the vented vessels had greater growth in the greenhouse than plants from non-vented vessels, with agar or OASIS foam (rigid boxes or sealed flexible bags). In vitro plantlets with larger crown diameter grew more quickly in the greenhouse, and when taken from vented vessels had the best greenhouse growth. Larger plants with crowns >30 mm produced in non-vented vessels did not demonstrate the faster growth observed in the vented treatments. After 6 weeks in the greenhouse, the largest plants originated from the vented vessels, and the smallest plants were from agar-cultured vessels. The Tissue Culture System that used OASIS foam in a vented flexible vessel, produced superior quality rooted plantlets because the root system was not disturbed during transfer. A second important benefit was that the acclimatization took place in the vented vessels on mist bed before transplant.