in Plant Kingdom by

1 Answer

0 votes

The Sphagnum has two distinct phases in the life cycle that is the gametophytic phase and the sporophytic phase. The plant body is haploid gametophyte and it is the dominant phase in the life cycle of Sphagnum. It is formed from the buds in the protonema which is itself is formed from the germination of the spore. The protonema is a one cell layer thick juvenile stage. The gametophytes undergoes sexual reproduction by developing the male sex organ the antheridia and the female sex organ the archegonia that are produced on the antheridial and archegonial branches respectively. Some sphagnum species are borne on the same plant known as the monoecious species where some others are dioecious species. Antheridia produces thousands of motile sperms called antherozoids and the archegonia contains a single egg. During fertilization, the sperm fuses with the egg and produce a diploid zygote that develops to the sporophyte. Since the sporophyte develops from the zygote it is also diploid. The sporogonium develops large number of microscopic spores which are produced as a result of meiosis. After the maturation of the capsule under the dry condition the lid or operculum burst opens resulting in the release of the spore. These spores on germination give rise to the protonema there begin the gametophyte generation. From the protonema several bud formation occurs; these buds give rise to number of gametophytic plant body thereby completing the life cycle.