李的大小孢子及雌雄配子体发育研究

STUDIES ON DEVELOPMENT OF MEGASPORE AND MICROSPORE, MALE AND FEMALE GAMETOPHYTES IN PRUNUS AMERICANA

以牛心李（ＰｒｕｎｕｓａｍｅｒｉｃａｎａＭａｒｓｈ）为材料，系统地观察了李的大小孢子与雌雄配子体发育，结果表明：①３月末～４月末为小孢子及雄配子体发育时期。小孢子母细胞减数分裂中，胞质分裂为同时型，呈四面体型排列，成熟花粉为２—细胞型，②４月中旬～５月初，为大孢子和雌配子体发育时期。双珠被、厚珠心，胚囊发育属单孢子蓼型。并对其发育的时序性、地域性等问题进行了讨论。

The development of megaspore and mierospore, male and female gametophytesin Prunus americana Marsh.was observed in a systematic way. The results arc as follows:1.The development of mierospore and male gametophyte is from the cud of Mar.to theend of Apr.In the meiosis of mierospore mother cells cytogenesis is simutaneous type, andthey arrange as tetrahedra. When the authors break,the matured pollen is 2-celled.2. The development of megaspore and female gametophytes is from the middle of Apr.to the beginning or May.That is bitegmic, crassinucellate and the development of the embryoabcs is monosporic polygonum.The sequence and region characters of the development were also discussed.