Direct shoot induction of Paeonia lactiflora ‘Zhong Sheng Fen’ and rejuvenation of hyperhydric shoots

Abstract

The underground buds of herbaceous peony (Paeonia lactiflora Pall.) ‘Zhong Sheng Fen’ were used to investigate the effects of indole-3-acetic acid (IAA) on culture initiation, benzyladenine (BA) on axillary shoot induction, and three auxins (IAA, indole-3-butyric acid [IBA] and 1-naphthyleneacetic acid [NAA]) on axillary shoot proliferation. In addition, methods to rejuvenate hyperhydric microshoots were established. Our results showed that the best initiation medium for ‘Zhong Sheng Fen’ was half-strength Murashige and Skoog (MS) medium supplemented with double the concentration of Ca2 + (880 mg L−1), 1 mg L−1 BA, 0.5 mg L−1 gibberellic acid (GA3) and 0.1 mg L−1 IAA. Axillary shoots were successfully induced by 2.0 mg L−1 BA. Several methods allowed the successful rejuvenation of hyperhydric microshoots, allowing them to develop normally. These included the addition of 3 g L−1 activated charcoal, the removal of ammonium nitrate from the medium, doubling the concentration of Ca2 + or eliminating BA from the medium.