Embryological study of Gentiana cruciata L. (Gentianaceae) from Bulgaria

Abstract

Embryological study on the Bulgarian native populations of Gentiana cruciata L. has been carried out. The anther is tetrasporangiate. Its wall develops according to Dicotyledonous-type and consists of epidermis, fibrous endothecium, two middle layers and glandular tapetum. The simultaneous microsporogenesis leads to formation of predominantly tetrahedral microspore tetrads. The mature pollen grains are 2-celled. The ovule is anatropous, tenuinucellate and unitegmic with unicellular archesporium. The development of the embryo sac follows the Polygonum-type and rarely - the Allium-type. The legitimate embryo and endosperm develop after double fertilization. The embryogenesis runs according to Asterad-type. Initially, the endosperm is nuclear. In some ovules somatic apospory was established