Study On The Rapid Propagation Techniques And Gametophyte Development Of Two Ornamental Ferns

Ornamental fern is the kind of fern with high ornamental value.By virtue of its verdant leaf color,beautiful leaf shape and diverse ecological adaptability as a shade plant,it has broad application prospects.This thesis chose Phymatosorus scolopendria and Microsorum punctatum as experiment materials.By means of reproductive techniques of spore sterile culture and conventional sporophyte induction,a rapid propagation system of Phymatosorus scolopendria and Microsorum punctatum was built,aiming to provide experimental and technical guidance for their large-scale reproduction,protection and development.Furthermore,the thesis also provided reference for protection and development of other ornamental ferns.Besides,whole processes of spore germination and gametophyte development of Phymatosorus scolopendria and Microsorum punctatum were observed and recorded by microscope,providing basic information for studies on the taxonomy of ferns.The main results were shown as follows:Spores of Phymatosorus scolopendria were selected as explants to do spore sterile culture:the optimal medium for spore germination was 1/4MS with 10 g·L^-1sucrose,and the optimal pH was 7.0⁸.0;the optimal medium for prothallus proliferation was 1/2MS without sucrose,and adding 0.5 mg·L^-1KT or NAA to the medium could effectively promote prothallus proliferation;the optimal medium for sporophyte formation was1/2MS without sucrose.However,the induction time of sporophyte was shortened,and the induction rate was increased by partial tissue culture.The optimal substrate for conventional sporophyte induction was black soil:perlite（1:1）,and the induction rate was up to 100%.By adopting the method of Knauss’s partial tissue culture method,the prothallus fragments of P.scolopendria developed into complete prothallus and formed sporophytes.This method saved a lot of work,but the formation time of sporophyte was not uniform.Spores of Mirosocrum punctatum were selected as explants to do spore sterile culture:The optimal time for spores sterilized by 4%NaClO solution was 3 min,the optimal medium for spore germination was 1/2MS with 10 g·L^-11 sucrose,and the optimal pH was7.0⁸.0;The optimal medium for prothallus proliferation was 1/2MS with 20 g·L^-1sucrose,and adding 0.5 mg·L^-1NAA to the medium could effectively promote prothallus proliferation;it was more difficult for sporophyte formation to be induced under sterile condition.However,sporophyte was able to be successfully induced by the partial tissue culture method,and the optimal substrate for sporophyte formation was a mixture of peat-soil:river sand（2:1）.The spore germination pattern of Phymatosorus scolopendria was Anemia type,and the development of gametophyte was Drynaria type.The types of trichomes included unicellular trichomes and multicellular trichomes distributed on the margin or back side of the gametophyte.Moreover,the spore germination pattern of Microsorum punctatum was Vittaria type,and the development of gametophyte was Drynaria type.The number of unicellular trichomes and multicellular branching trichomes growing on the margin or back side of the gametophyte was relatively smaller.