Abstract:

The formation and development of sporoderm of the fern Stenoloma chusanum Ching (Lindsaeaceae) are studied by means of light microcope (LM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results as follow: the mature spores of Stenoloma chusanum Ching are bilateral and monolete. The surface of spore is
smooth and shows a verrucate ornamentation. The sporoderm consists of endospore, exospore and perispore. The exospore which is formed by sporopollenin finishes its formation in the tetrad stage . Its surface is smooth and its texture is uniform. The perispore is formed by the tapetal residues which deposit on the outside of the exospore . The perispore can be distinguished into three layers, i. e. an outer perispore layer, a middle perispore layer and an inner perispore layer. It is obvious that a layer of space exists between the middle and the outer perispore layers. In the last, the formation and development of the spore wall are discussed. The results will contribute to a better understanding of the origin, development and
formation process of the sporoderm of ferns. It also can provide basic information for the palynology and phylogeny .

Key words: Stenoloma chusanum