Research Advances about Developmental Mechanism of Somatic Embryos in Conifers Ultrastructural Studies on the Development of Zygote and Proembryo in Plantago major Ultrastructural Studies on the Development of Zygote and Proembryo in Plantago major Isolation of Zygotes and Proembryos in Doritis pulcherrima Ovule Development and Seed Formation of Calanthe tsoongiana T.Tang et F.T.Wang Research Progress in Suspensor of Angiosperms ISOLATION AND CULTURE OF PROTOPLAST FROM EMBRYONIC SUSPENSION CELL OF PINUS TAEDA LINN.