This study was conducted to establish the best mass propagation system considering each developmental stage from spore germination to prothallus propagation and sporophyte formation, by selecting native 8 ferns of Dryopteridaceae, such as Arachniodes aristata (G. Forst.) Tindale, Dryopteris uniformis (Makino) Makino, Polystichum polyblepharum (Roem. ex Kunze) C. Presl, Cyrtomium fortunei J. Sm., P. braunii (Spenn.) Fee, D. fragrans (L.) Schott, D. nipponensis Koidz. and D. erythrosora (D. C. Eaton) Kuntze with high horticultural value.
As a result of culture to investigate the effect of medium kinds and concentrations on spore germination of 7 ferns, 6 species, such as A. aristata (G. Forst.) Tindale and P. polyblepharum (Roem. ex Kunze) C. Presl, showed the highest germination rate in Knop medium within 30 days, and the development into early prothallus after germination was excellent. Whereas, D. erythrosora (D. C. Eaton) Kuntze showed good germination rate and prothallus development of a spore in 1/2MS medium, so it was judged that the elements of reasonable medium demanded on spore germination of ferns are different by species.
To multiply prothallii formed after spore germination, nutritional requirements, sucrose, activated carbon and nitrogen sources were different according to species. Prothallus of 6 ferns showed excellent growth and development commonly in MS medium. However, D. uniformis (Makino) Makino showed the vigorous proliferation of prothallus in 1/2MS medium, and P. braunii (Spenn.) Fee showed excellent growth and development of prothallus in 2MS medium containing the high concentration of vitamins and inorganic substances.
In addition, the concentration of sucrose needed for growth and development of prothallus showed a great difference by species, and the reasonable concentration of sucrose by species was that D. fragrans (L.) Schott was 4%, A. aristata (G. Forst.) Tindale, D. uniformis (Makino) Makino, C. fortunei J. Sm., and P. braunii (Spenn.) Fee were 3%, D. nipponensis Koidz. was 2%, and P. polyblepharum (Roem. ex Kunze) C. Presl and D. erythrosora (D. C. Eaton) Kuntze were 1%. The addition of activated carbon in the medium worked in 4 species. The prothallus growth and development of P. polyblepharum (Roem. ex Kunze) C. Presl, C. fortunei J. Sm., and D. fragrans (L.) Schott were excellent in the medium containing 0.2% of activated carbon, and D. uniformis (Makino) Makino in 0.8% of activated carbon. About nitrogen source in medium, the addition of 60mM that ammonium (NH4+) and nitrate (NO3-) nitrogen were 20:40mM worked in 6 species of fern. Exceptionally, prothallus proliferation of P. polyblepharum (Roem. ex Kunze) C. Presl was effective with 60mM of ammonium nitrogen and D. fragrans (L.) Schott with 60mM of nitrate nitrogen.
As a result of an experiment to select the reasonable soil to promote the sporophyte formation from proliferated prothallus, production and growth of sporophytes by species were different according to mixing ratio of horticultural bed soil, pearlite, decomposed granite, and peatmoss. Five species such as A. aristata (G. Forst.) Tindale and D. uniformis (Makino) Makino showed a high formation of sporophytes in soil mixed horticultural bed soil, and pearlite or decomposed granite in the proportion of 2:1 (v:v), and also showed excellent growth and development in the same soil. Whereas, when horticultural bed soil and decomposed granite were mixed in the proportion of 2:1 (v:v), sporophyte formation of D. nipponensis Koidz. was excellent, but growth and development were active in the single use of horticultural bed soil. So it is necessary to consider the market price by kinds of soil.