Reproduction in Anthoceros

                                                     

Reproduction in Anthoceros is performed by all the three modes ie. vegetative, sexual and asexual.

Vegetative and sexual reproduction is found in gametophyte thallus, whereas asexual mode of reproduction (spore formation) is available in sporophye.

Vegetative reproduction:

a) Death and decay of older parts of the thallus causes separation of the terminal branches, these branches grow into new individual thallus.

b) Tuber formation is another option for vegetative reproduction in Anthoceros. Tubers are formed at the margin of the thallus, these tubers remain active even after death of the thallus and germinate into new thallus.in next favourable season.

Gemmae may be developed along the margin of the thallus in different species. It germinates after detachment from the thallus and forms new thallus.

Sexual reproduction: 

Anthoceros may be of monoecious (bisexual or homothallic) or dioecious (uni sexual or heterothallic). Monoecious species are generally protandrous (antheridia develop earlier than archegonia). Both the reproductive structures develop on the dorsal surface just behind the growing point of the thallus.

Antheridia: 

Antheridia may develop singly or in group(number may be varied) inside the antheridial chamber. A mature antheridium has a multicellular stalk and on he stalk the club shaped body is present. The body of the antheridium has a single cell layered jacket. The jacket is green in nearly mature condition but at full maturity it urns into red or bright ornage in colour. Inside the jacket mass of androcyte (antherozoid mother cell) cell are present. Each androcyte is metamorphosed into a single biflagellate antherozoid or sperm.

In presence of water the jacket of mature antheridium rupture at terminal position and the mass  of androcyte comes out. At final each androcyte forms a single antherozoid.

Archegonium: 

Archegonia are found on the thallus in embedded condition but the cover cells remain free on the surface. The mature archegonium consists of venter and neck but not surrounded by jacket layer (gametophyte tissue surrounds the structures), the neck has 4-6 neck canal cells, inside venter a ventral canal cell and a large egg is present. At the terminal of neck cover cells are found.

At maturity the cover cells disintegrate and the neck canal cell and ventral canal cell forms a mucilaginous matrix by interacting with water.

         

Fertilization:

Fertilization occur in presence of water. After formation of the mucilaginous matrix inside the archegonium, it comes out through the opened neck and form a mucilaginous mound. Antherozoids also migrate in presence of water and being attached to the mound, now the antherozoid enters through the neck and reach at venter to the egg.  Ultimately asingle antherozoid fuses with a single egg inside the venter and that how fertilization takes place. As a result of fertilization a diploid zygote is formed inside the venter.