Spore Culture and Gametophyte Development of Dryopteris varia (L.) Ktunze Effects of amino acid-N and ammonium-N on wheat seedlings under sterile culture Studies on Spore Propagation of Pteris cretica ‘Albo-lineata’ Effects of different nitrogen forms on rice seedlings under sterilized culture at high temperature Studies on totally and partially enclosed sterile culture methods used in the research of rice organic nutrition Studies on Spore Propagation of Pteris cretica ‘Albo-lineata’ Development Process and Spore Sterile Culture of Pteris wallichiana Agardh.