“金丝4号”枣大小孢子发生及雌雄配子体发育

摘要

为探明枣有性生殖过程中是否存在生殖障碍,以“金丝4号”枣为试材,采用石蜡切片技术,对其大小孢子发生及雌雄配子体发育过程进行了观察.结果表明:“金丝4号”枣花药为4室,花药壁4～5层,分别为表皮、1～2层药室内壁、中层和腺质绒毡层,花药壁的发育属于基本型；小孢子母细胞胞质分裂为同时型,四分体排列多为正四面体；花粉为三角形,具3个萌发孔,3沟,成熟花粉为2-细胞型；大孢子母细胞经减数分裂中期、后期、末期形成的四分体大孢子呈线型排列,合点端的功能大孢子经过3次有丝分裂,最后形成7细胞8核胚囊；倒生胚珠,双珠被,厚珠心,蓼型胚囊.%In order to test whether there was any obstacle of reproduction in the process of sexual reproduction,the microsporogenesis,megasporogensis and development of male and female gametophytes in Ziziphus jujube Mill cv ‘jinsi No.4’ were observed by paraffin section technique.The results show that each anther in Z.jujube Mill cv ‘jinsi No.4’ has four cells,anther wall is from four to five layers,which are the epidermis,1-2 layers of endothecium,middle layer and glandular tapetum layers,and the development of anther wall is of basic type.The meiosis in the microspore mother cells is belonged to simultaneous type,and the most of the tetrads are arranged in a regular tetrahedron shape.The shape of pollen is triangular with three germination pores and three furrows,and the ripened pollen is of 2-cell type.The megaspores in tetrad are in a linear arrangement,which form from megaspore mother cell through middle period,later period and end period of meiosis.After three times mitosis,the functional megaspore at chalazal end forms a embryo sac with seven cells and eight nucleus.The ovule is anatropous,two integuments,crassinucellate.The development of embryo sac is belong to Polygonum type.