Tissue interactions in the developing locule of Gasteria verrucosa during microsporogenesis

We investigated the development of the locule tissues of Gasteria verrucosa (Mill.) H. Duval during microsporogenesis using electron microscopy and summarized it in detailed pen-drawings. In the early stages of development, the epidermis, endothecium and middle layer show no remarkable processes relating to tapetum and pollen development. The tapetum regulates the disappearance of the original cell walls and the callose walls from the microspores and itself. These wall materials partly turn into starch in both tissues. The spherical shape of the meiotic callose walls and the presence of the cytomictic channels enable the pollen mother cells to divide into equally shaped microspores, which is important for random dispersal.