Research on tissue rapid breeding technology of endangered plant Cibotiumbarometz (L.) J. Sm.

Abstract This research aimed to establish the Cibotium barometz tissue rapid breeding technology and provide a theoretical basis for its artificial breeding and industrial planting. The spores' germination conditions were selected, along with the optimum sterilization time and spore germination medium. The germination material was incubated in different basic media to select a basal medium suitable for proliferation and differentiation. Based on the results of basic medium screening, the proliferation orthogonal and differentiation experiments were performed to screen the best media, and then the C. barometz rooting experiment was performed in two single-factor experiments by using the differentiated sporophytes as materials. The optimal sterilization time of C. barometz spores was 11 minutes and the best medium for germination was 1/8MS medium supplemented with 0.02 mg/L IAA. MS medium was suitable for the proliferation and differentiation of tissue culture seedlings, while the WPM medium was suitable for sporophyte differentiation. The best medium for growth was the MS medium, supplemented with 1.0 mg/L IAA and 0.5 mg/L 6-BA. Concentrations of sucrose had a significant effect on the differentiation of tissue culture seedlings, while no sucrose culture had barely any growth or differentiation effect on sporophytes. The effect of proliferation and differentiation was the best when sucrose concentration was set at 20 g/L. Low concentration cannot limit the growth or differentiation, while high concentration may inhibit those processes. The PGRs including IAA, NAA, 6-BA, and GA3 had better differentiation effects, but the KT was slightly weaker. The rooting rate of sporophytes initially increased and then decreased with the concentrations of ABT, IBA, and IAA. The rooting rate reached the maximum when the concentrations of ABT and IBA were at 1.5 mg•L -1 and IAA was at 1.0 mg•L -1 (which were 86.82%, 91.52%, and 90.89%, respectively). Compared with ABT and IAA, IBA had a significant effect on the average and the longest root length of C. barometz, and the three PGRs had no obvious effect on the average or maximum diameter. The optimal cultivation conditions for the organization of rapid breeding technology from the germination, growth, differentiation, and rooting of C. barometz were obtained, and the sporophytes were successfully transplanted to the external environment, and all these results provided a theoretical reference for the industrial planting of C. barometz.