Abstract:In order to further improve the pitaya varieties and yield, young stem segments of Zihonglong with red skin and red pulp were used as the test materials. Through selecting various plant growth regulators and concentration ratio, the culture medium, which was suitable for callus induction, adventitious bud regeneration and root formation, was screened to establish a stable, rapid and efficient plant regeneration system in pitaya (Hylocereus polyrhizus ‘Zihonglong’). The result indicated that high concentration of TDZ was beneficial to the callus induction, but not conducive to the adventitious bud regeneration. Vertical placement of the explants was better than horizontal placement for callus and adventitious shoot induction. The best medium for callus induction and adventitious shoot regeneration, through orthogonal designing with TDZ, 2,4-D and NAA, was MS medium supplemented with 1.0 mg ·L-1 2,4-D, 0.4 mg ·L-1 TDZ and 0.5 mg L-1 NAA, in which the callus induction rate was 89.1% and the adventitious shoot regeneration rate was 94%, The optimal medium for rooting was MS medium containing 0.5 mg ·L-1 CCC, 3.0 mg ·L-1 BA and 200 mg ·L-1 AC, which resulted in a rooting rate of 97%, the average root number of 7.0 and average root length of 10.3 cm.