Abstract: The effect of inorganic salts level, sucrose, mannitol and plant growth inhibitor PP₃₃₃ on In vitro conservation of Dioscorea bulbifera L. virus-free plantlet stems with a bud in MS basic medium was studied using single-factor experiments and orthogonal experimental method. The results showed that the survival rate of D.bulbifera L. virus-free plantlet stems with a bud which cultured on 1/4MS medium containing 2.0 mg·L^-1 KT, 0.5 mg·L^-1 NAA, 30 g·L^-1 sucrose, 20 g·L^-1 mannitol and 4 mg·L^-1 PP₃₃₃ and stored at 25±1℃ temperature was over 90%. After morphological indexes measurement, physiological and biochemical indexes determination and RT-PCR analysis, the genetic variation and PVY of In vitro conservation D.bulbifera L. virus-free plantlets were not detected. The results provided a simple and effective way for In vitro conservation of D.bulbifera L. virus-free plantlets germplasm.

Key words: Dioscorea bulbifera L., virus-free plantlets, germplasm, In vitro conservation