Callose in Cell Walls during Reproductive Processes in Cytinus Hypocistis L.

SUMMARY

Micro- and macrosporogenesis, as well as megagametogenesis and fertilization were studied by fluorescence microscopy in Cytinus hypocistis in order to get new data on the role played by callose in the reproduction process. Callose is present in the whole cell wall of the megasporocytes; the fluorescence decreases during the reductional division and disappears nearly completely before the equational division. Dyads, triads and tetrads show an intense callose fluorescence in the newly formed cell walls. In the megagametophyte the filiform apparatus exhibits the stronger fluorescence lasting till the entry of the pollen tube inside the embryo sac; it is no longer detectable after fertilization. The cytokinesis leading to the microspore formation is successive and the tetrads disposition is isobilateral. The role played by callose in the reproduction process is discussed.