Some aspects of embryology of the Poacynum armenum (Apocynaceae)

Abstract

The article presents some aspects of Poacynum armenum (Pobed.) Mavrodiev, Laktionov et Yu.E .Alexeev embryology. The processes of the male and female generative structures, endosperm formation have been described. Plant material was collected in the area of Cape Sarych on the Southern Coast of the Crimea during flowering and fruiting Poacynum armenum . It has been established that the type of microsporangium wall formation is centrifugal, the formation of microspores tetrads is simultaneous, the mature pollen is 3-cell with a three-furrow shell, the ovule is anatropic, unitegmal, tenuinucellate. Endosperm is cellular with chalazal haustorium. It is shown that one of the reasons for low seed productivity can be significant deviations in the development of male gametophytes and gametes, as well as the absence of pollinating insects during the flowering period. The activity of the sea and anthropogenic impact also have a negative effect, as well as the absence of pollinating insects during the flowering period. However, the formation of full seeds, the presence in this coenopopulation along with generative individuals of seedlings and juvenile individuals indicate seed reproduction of the species and the possibility of its natural renewa