Abstract:To better understand the aborted seed of cultivated Syringa microphylla Diels in Beijing,we observed the embryo development of S.microphylla.(1)The fruit setting rates from artificial self-pollination and controlled emasculation were 0 while intraspecific crossing pollination and natural pollination were 20.37% and 9.13% respectively.The setting rates from four pollination methods were all 0;(2)The anther wall conformed to the basic type and glandular tapetum.The cytokinesis of the microspore mother cells in meiosis was the simultaneous type,and microspore tetrad was mainly tetrahedral shape.The mature pollen grains were of 2-celled type.The ovule was anatropous,unitegmic and tenuinucellate,megaspore tetrad was linear shape.The development of the embryo sac was the polygonum type.The endosperm developed to be the nuclear type and the embryo the asterad type.The globular embryo,heart-shaped embryo,torpedo embryo and cotyledonal embryo were formed sequentially.However,the development of the cotyledonal embryo stopped and all cells gradually degraded in early September.The study showed that S.microphylla was cross-pollinated plant,the method of the intraspecific crossing pollination could increase the fruit setting rates,while no viable seed was harvested.The microspore and megaspore,male and female gametophytes,pollination fertilization and early embryo development were normal,but the later embryo growth stopped.