Morphology of Marsilea Systematic position Kingdom : Plantae - CEC

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Fig. 13 Diagrams showing stages in the dehiscence of Marsilea sporocarps. Gematophytic generation The microspores and the megaspores germinate separately to produce male (micro-) and the female (mega-) gametophytes. The microspores germinate immediately after shedding, forming small biconvex prothallial cell and a large apical cell. The apical cell by repeated divisions ultimately forms androcytes or antherizoid- mother cells. Each androcyte metamorphoses into a cork screw-shaped multiflagellate antherizoid, characterized by the presence of a prominent terminal vesicle (Fig. 14). Fig. 14 Marsilea: screwshaped multiflagellate antherizoid, characterized by the presence of a prominent terminal vesicle. Similarly, megaspore undergoes division, forming small nipple-shaped apical cell and a large basal prothallial cell. The apical cell forms the female
gametophyte, while prothallial cell provides nutrition to the developing gematophytes (Fig. 15). Fig. 15 Marsilea: germination and development of the female gametophyte. Fertilization: The neck canal cells and the ventral canal cell degenerates to form a mucilaginous mass, which attracts sperms chemotactically. One of the sperms fuses with the egg to accomplish fertilization and form the diploid zygote. The zygote is the mother cell of the next sporophytic generation and develops into a young sporophyte within 2-4 days after fertilization. Embryogeny: The fertilized egg (zygote) enlarges in its size and secretes a thin cellulose wall around it. It enters into rapid divisions, to give rise to a young sporophyte within 2 - 4 days. Zygote divides vertically and produces two unequal cells. The larger cell is known as the epibasal cell, and the smaller one as the hypobasal cell. These two cells undergo transverse divisions to form a quadrant embryo. The cells of the quadrant embryo show definite relation to the primary growth of the embryo. Epibasal half produces
Page 1 and 2: Morphology of Marsilea Marsilea, co
Page 3 and 4: Root: The primary root formed on th
Page 5 and 6: Anatomy of Marsilea Rhizome (Stem)
Page 7 and 8: Leaflet Fig. 5 Marsilea:Transverse
Page 9 and 10: Vascular bundle lies within the end
Page 11 and 12: Fig. 8 Marsilea: different modes of
Page 13 and 14: cell for the second sporocarp. This
Page 15: its development. The outer cell of
Page 19: produced within the fruit body, the

Morphology of Marsilea Systematic position Kingdom : Plantae - CEC

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