ABSTRACT
Pollen means a male gametophyte (see microspores). W hen the cell is added (artificially or, as in nature, by wind or insect-pollinators) to the surface of the pistil stigma in a flower or on the surface of female Gymnosperm microstrobils, it can germinate: forming an amoebe-like emergence called a pollen tube (Stanley and Linskens, 1974). The division of the pollen nucleus leads to the appearance of spermia which move along the growing pollen tube to the egg cell. So fertilization occurs. Resin ducts and reservoirs are secretory structures that contain resin (complex terpenoid composition). The structures are especially abundant in conifer plants. Trichomes (also see hairs) are unicellular or multicellular secretory structures which originate from epidermal cells on plant surfaces. Vegetative microspores - non-sexual cells serve for vegetative breeding of spore-breeding plants (see microspores). During their development the unicellular organism converts to multicellular thallus, which later forms sexual organs. Viable or non-viable microspores - cells, which are able to germinate in nature or in the artificial nutrient medium.
