Embryology of Juglans mandshurica Maxim. (I) the Microsporogenesis,and the Development of Male Gametophytes

Microsporogenesis and development of male gametophytes were systenatically studied. Microspore mother cells (pollen mother cells) possess four pollen sacs ,the pollen sac includes the epidermis,fibrous layer,middle layer and tapetum.Anther wall development belongs to the basical type.The tapetum belongs to galandular type. Pollen grains middle layer and tapetum dispear gradually during the pollen development.The cytokinesis after meiotic division of PMCs is simultaneous and the microspore arrangement in the tetrad is tetrahedral.Later,terads are divided into to 4 single-cell.Mature pollen is 2-cells type.