STUDY ON TECHNIQUES TO IMPROVE THE SURVIVAL RATE AND GROWTH OF PHU THO’S 5-PETALED WHITE ORCHID IN VITRO IN THE ACCLIMATIZATION STAGE

Tóm tắt

Hardening in vitro orchid plantlets to adapt to the ex vitro environment is a decisive step to the final quality of the tissue culture products. The acclimatization of the Phu Tho’s 5-petaled white plantlets was carried out in a greenhouse by controlling relative humidity and the light intensity. Research results have shown that, the leaving containers of Phu Tho’s 5-petaled white plants for 7 days in the greenhouse, then opening the lid for 2 days, has helped the plantlets gradually acclimate to the natural environment to achieve the survival rate of 89.44%. Plantlets growing in a greenhouse in a condition that was shaded 50% and watered two times a day in the early morning and late afternoon got a survival rate of 92.22%, plant height of 4.35 cm, with an average of 12.05 roots, 6.77 leaves per plantlet, and leaf surface width of 1.85 cm. NPK fertilizers at the concentration 1.0 g/l were applied with the ratio of 30:10:10 periodically every 7 days after 1 month of planting. As the result, after 12 weeks, the plantlets have achieved the height of 8.55 cm, the trunk diameter of 1.11 cm, the number of leaves of 12.09, the number of roots 16.10, and the plantlets were sturdy and healthy.