In vitro adventitious regeneration and plantlet transplantation of Atractylodes chinensis (DC.) Koidz., a valuable medicinal plant

Abstract

Triploid Atractylodes chinensis (DC.) Koidz. (A. chinensis) is a valuable genetic resource for medicinal plant breeding, and there is a demand to develop an efficient in vitro regeneration protocol to resolve triploid sterility in production. In this study, the effects of sterilization, bud type, 6-benzyladenine (6-BA) combined with 1-naphthaleneacetic acid (NAA) or indole-3-butyric acid (IBA) and transplanting materials on shoot regeneration, rooting and growth were explored. The genetic stability of regenerated plants was verified using flow cytometry (FCM) and simple sequence repetition (SSR) molecular markers. When axillary buds were sterilized with sodium hypochlorite for 30 min and cultured on Murashige and Skoog (MS) + 1.5 mg·L-1 6-BA + 0.4 mg·L-1 NAA medium, the regeneration rate was 61.33%. Strong roots occurred on 1/2 MS combined with 3% sucrose and 0.6 mg·L-1 IBA medium. Rooting plantlets transplanted into a mixture of peat soil: perlite (1:1, v/v), the survival rate up to 90.00%. Histological analyses revealed that shoot meristematic cells derived from cambium cells developed into the apical meristem and formed shoots. FCM analysis determined that the ploidy levels of 20 random regenerated plants were coincident with explants, the number and size of bands obtained by 6 pairs of SSR polymorphic primers were consistent. The results of this study show that our in vitro adventitious regeneration and plantlet transplantation protocol of triploid A. chinensis was efficient and produced strong genetic stability.