Establishment of a Tissue Culture and Rapid Propagation System of Dryopteris fragrans

Dryopteris fragrans is a perennial herb fern with medical and economical values, such as anti-oxidation, bacteriostasis, anti-psoriasis, and anti-tumor. The wild resources of D. fragrans are scarce. Establishing a regeneration system for D. fragrans through tissue culture is needed to enable a sustainable use of this valuable resource. In this experiment, through sterile culture of spores of D. fragrans, the effects of different factors on prothallium proliferation, sporophyte induction, callus induction and proliferation, cluster bud differentiation, and rooting were compared and analyzed to establish a rapid propagation system, which laid the foundation for large-scale production of D. fragrans. The results showed that 1/2MS medium provided optimal growth with green color and a multiplication factor up to 5.67±0.59. The obtained plants have numerous young spores, and the spore induction rate was (37.50±2.04)%. The most efficient callus induction medium contains 1/2MS media supplied with 2.0 mg·L^-1 6-BA, and 1.0 mg·L^-1 2,4-D, which reached an induction rate up to (96.67±5.77)%. The optimal callus proliferation medium we obtained was 1/2MS media supplied with 1.0 mg·L^-1 6-BA, and 0.5 mg·L^-1 2,4-D, which reached a proliferation factor of 13.30. The obtained granular callus produced a large number of cluster buds (53.33±3.33)% in 1/2MS medium, and 1/2MS media supplied with 0.2 mg·L^-1 NAA medium promoted rooting, resulting in a transplanting survival rate of ~60%.