Abstract: The selection of different peony explants and sterilization methods were studied to suppress the high contamination rate in underground bud tissue culture of peony. The results show that healthy plump underground buds in moderate size should be first considered and different HgCl₂ sterilization time should be applied according to the buds’ size, and 5-8 min is advisable. Striping several outer scale layers and leaving at least 2 inside scale layers and choosing the one-step sterilization method could reduce the contamination rate and ensure a thorough sterilization.

Key words: Paeonia lactiflora, underground buds, tissue culture, contamination