%0 Journal Article %A DU Yi-Ming %A ZHONG Yuan %A SHANG Hong-Qin %A CHENG Fang-Yun %T Callus Induction and Differentiation from the Filaments of Paeonia ostii ‘Feng Dan’ %D 2020 %R 10.7525/j.issn.1673-5102.2020.04.005 %J Bulletin of Botanical Research %P 514-522 %V 40 %N 4 %X With the filaments of Paeonia ostii as explants, the effect of developmental stage of explant, basal media and PGRs on callus induction, proliferation and differentiation were investigated, and the morph-histological observation of different types of callus was performed. The translucent and white filaments from flower bud of 13-19 mm in diameter is optimal for callus induction. The optimal callus induction medium was SH containing 1 mg·L-1 2,4-D, 2 mg·L-1 NAA and 0.2 mg·L-1 BA. The optimal proliferation medium was SH containing 0.5 mg·L-1 2,4-D, 0.5 mg·L-1 NAA and 0.25 mg·L-1 BA, and the proliferation rate was 3.86. The filaments callus can be divided into three types according to their morphological and microstructural characteristic, the type Ⅰ callus presented typical embryogenic callus characteristics, and somatic embryogenesis was observed from this kind of callus; there were plenty of vascular tissues formed in the type Ⅱ and type Ⅲ callus, and shoot organogenesis was observed from the type Ⅱ callus, but no morphogenesis from the type Ⅲ callus. These results suggested that the filaments have important regeneration potential as a good novel explant source, which have important value in establishing in vitro regeneration system of tree peony. %U https://bbr.nefu.edu.cn/EN/10.7525/j.issn.1673-5102.2020.04.005