Some features of the embryology of the twin-leaf squill {Scilla bifolia L.)

Abstract

The paper presents the results of studying the processes of development of male and female generative structures of one of the species of the Asparagaceae family - Scilla bifolia L. It is shown that the microsporangium wall develops according to the monocotyledonous type and consists of epidermis, endothecium, middle layer consisting of two layers of cells, and tapetum. Sporogenic tissue is represented by two or three rows of cells, tetrads of microspores are formed successively. Pollen grains are two-celled. The gynaeceum consists of a single pistil with an upper trilocular ovary. The ovule is anatropic, crassinucellate, bitegmal, medionucellate, funicular. The micropyle is formed by an internal integument, which, growing, forms an operculum in the apical part, and the external integument forms a caruncle, or arilloid. The germ sac is octonucleate, 7-celled, synergids with a filamentous apparatus, have small beak-like outgrowths. The egg cell is somewhat rounded, elongated, with a typical arrangement of cytoplasm, nucleus and vacuole. Scilla bifolia is pollinated by insects, which are attracted by the pleasant aroma and bright color of the perianth. The endosperm is helobious. The fruit is a spherical-three- lobed, trilocular box with brownish seeds. It is propagated by seeds and vegetatively, the type of seed gennination is underground.