XVI International Botanical Congess
Apomixis (A) in flowering plants is defined as seed production without meiosis and (or) fertilization. The origin and inheritance of A is still unclear. Molecular biologist are searching for the mutations and the genetic factors responsible for A. Morphological studies of reproductive structures in different A types (apospory, diplospory, adventive embryony) show the main structural and functional regularities of the developmental processes. Differentiation of A initials are based on: increase of cell, nucleus and nucleolus size, cell isolation by the thickening of the cell wall and closing of the plasmodesmata, reorganization of the protoplast via changes and intensification of the biosynthetic processes (proteins). The pathway of sexual and A reproductive structures, their differentiation and development, and viable seed formation are generally similar in both types of reproduction.