| The embryology in Tilia miqueliana of Nanjing Forestry University was studied systemically using the paraffin cut method in micro level.The research included its flower bud differentiation, megasporogenesis, the development of female gametophyte, microsporogenesis, the development of male gametophyte, fertilization, the development of embryo. The main results of the studies were as follows:1. Tilia miqueliana hiemal bud belonged to mixed bud. After the sprout of mixed bud, flower bud was formed in leaf axil. Flower bud was differentiated in the same year from the end of March to the early May(in Nanjing). The differentiation included two processes with inflorescence differentiation and floret differentiation. The flower bud differentiation took about 35 to 40 days totally,and it was that of short duration and fast development.2. The pollen longevity of Tilia miqueliana was relatively short, the optimal moisture content was 8.99%.3. Archesporial cells formed in middle April. In early May, the microspore mother cell started its meiosis. The cytokinesis of microspore mother cell during meiosis was of simultane- aous type. Its tetrasporophyte was tetrahedral. The observation showed: The development of the microspore mother cell was nonsynchronous in most condition. The anther matured in late May.4. The ovary of Tilia miqueliana had 5 rooms and each room had 2 ovules. Ovule primordial formed on 24th April, embryo matured in late May. Stigma belonged to wet stigma. Tilia miqueliana had 5-splited stigma and empty stylar canal. Pollen tubes could develop along the style after entering papillas.5. The main reasons for low seed plumpness of Tilia miqueliana were:â‘ Most of the fertilization process was abnormal. Namely, after pollen tube entered the embryo sac, one sperm syncretized with secondary nucleus, and formed primary endosperm nucleus; the other sperm did not syncretize with egg cell normally.â‘¡Endosperm of Tilia miqueliana degenerated rapidly after a certain period of time and aborted.
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