Open Style - Style of Stigma Interaction
Aegle, Fritillaria, Lilium spp. have variable number of stylar canals depending on the number of carpels. The epidermal cells of stylar canal divide actively and become papillate in acropetal succession. In Lilium each cell contain 1-5 nuclei which later fuse. The stylar canal thus becomes lined with highly glandular and secretory cells which are dome-shaped with a thick outer tangential wall (canal cells). The wall towards the canal is smooth but is highly convoluted towards the interior of the cells. In Citrus the inner tangential wall of canal cells is thick and made up of fibrillar homogeneous and granular nonhomogeneous material. The canal cells have a large nucleus and often become multinucleate.
Cytoplasm is rid in organelles such as mitochondria, dictyosomes, free ribosomes or polysomes, smooth and rough ER and occasional amyloplasts. It is supposed that a main portion of the secretion product is transported to the canal cells from the neighboring parenchyma cells through the numerous plasmodesmatal connections. The golgi apparatus of canal cells of Lilium regale and Lilium devidii secrete a non- cellulosic and amorphous polysaccharide containing mucilage during the bud stage. This is easily transported to the outer walls of canal cells. In L. longiflorum, the secretion products of the canal cells are retained with the help 'of a thin and continuous layer of cuticle until after pollination. The stigmatic papillae of Lilium lack the characteristic secretory zone seen in canal cells and the stigmatic exudate is known to appear before pollination. The stigmatic exudate, may, therefore be a secretion product of the canal cells transported through the intercellular spaces. The stylar exudate is produced in two phases in Lycopersicon; the first contains carbohydrate and the second proteins.