Ampelopsis brevipedunculata (Maxim.) Trautv., also known as porcelain berry, has been used for many years as herbal folk medicine to treat liver diseases. This study was conducted to assess the influence of various factors on the rooting of hardwood stem cuttings of this plant species, collected from Jeju Island (Korea). Three experiments were conducted: (1) Stems of three diameters (≤ 4.5, > 4.5 – < 6.5, or ≥ 6.5 mm), (2) four types of rooting media [rockwool cubes, perlite, peat moss + perlite (3:1, v/v), or vermiculite] and (3) indole-3-butyric acid (IBA) at four treatment concentrations (0, 100, 200, or 400 mg·L-1). For the IBA concentration experiments, cuttings of the various diameters were inserted to a depth of 2 cm in a commercial propagation medium in 72-cell plug trays. The planted stem cuttings were initially placed on a fog bench for 16 days at 95% ± 5% relative humidity at a temperature of 25°C ± 3°C under 95% shade. The stem cuttings were then transferred to a greenhouse bench under ambient light and fed a nutrient solution on a daily basis for 2 weeks. Among the tested stem diameters, cuttings with a stem diameter ≥ 6.5 mm produced the largest stem diameter (2.6 mm) of new shoot, but without root growth. Initial stem diameter significantly affected the length of the new shoot, and the longest shoot length (67.8 mm) was observed in cuttings with an initial stem diameter of ≥ 6.5 mm. Cuttings inserted in vermiculite produced the largest diameter of new shoot (2.4 mm), whereas cuttings grown in rockwool cubes produced the shortest, stem diameter of new shoot growth (1.9 mm). No significant differences (p ≤ 0.05) were observed in the length of new shoot growth among the various rooting media and IBA concentrations. Furthermore, all tested IBA concentrations failed to induce rooting. Collectively, these results suggest that porcelain berry cuttings with an initial diameter of ≥ 6.5 mm have higher survival and bud break, but they did not produce rooting. Further studies are needed to optimize the protocol for the rooting of hardwood stem cuttings of A. brevipedunculata (Maxim.) Trautv.

Abstract
 Introduction
 Materials and Methods
  Plant materials
  Experiment 1. Effect of cutting diameter on the rooting of hardwood cuttings of A. brevipedunculata
  Experiment 2. Effect of rooting medium on the rooting of hardwood cuttings of A. brevipedunculata
  Experiment 3. Effect of IBA concentration on the rooting of hardwood cuttings of A. brevipedunculata
 Growth measurements of cuttings
 Statistical analysis
 Results
  Experiment 1. Effect of cutting diameter on the rooting of hardwood cuttings of A. brevipedunculata
  Experiment 2. Effect of rooting medium on the rooting of hardwood cuttings of A. brevipedunculata
  Experiment 3. Effect of IBA concentration on the rooting of hardwood cuttings of A. brevipedunculata
 Discussion
  Experiment 1. Effect of cutting diameter on the rooting of hardwood cuttings of A. brevipedunculata
  Experiment 2. Effect of rooting medium on the rooting of hardwood cuttings of A. brevipedunculata
  Experiment 3. Effect of IBA concentration on the rooting of hardwood cuttings of A. brevipedunculat
  Conclusion
 References

• Dong Il Kang(Division of Applied Life Science Graduate School (BK 21 Plus Program), Gyeongsang National University)
• Luc The Thi(Division of Applied Life Science Graduate School (BK 21 Plus Program), Gyeongsang National University)
• Hyun Jin Kim(National Institute of Biological Resources, Ministry of Environment)
• Byoung Ryong Jeong(Division of Applied Life Science Graduate School (BK 21 Plus Program), Gyeongsang National University, Institute of Agriculture and Life Science, Gyeongsang National University, Research Institute of Life Science, Gyeongsang National University) Corresponding author