STRUCTURE AND EVOLUTION IN GAMETOPHYTES, SPOROPHYTES

This ppt is about structural organization and evolution of gametophytic and sporophytic phase of bryophytes and there economic uses.

1. BRYOPHYTES NOTES NIHARIKA

2. Bryophyte Structural organization and evolution of gametophytes Gametophyte

3. h Life cycle Classes HEPATICOPSIDA ANTHOCEROTOPSIDA BRYOPSIDA Hepaticopsida 4 Riella Asymmetrical gametophyte. Erect axis. Single conspicuous straight to spiral twisted plate like Wing. Ventral scale borne along the median of axis. Rhizoids are restricted to first formed parts. Riccia Dichotomous branching – Rosette. Dorsal surface – median furrow. Lower – colourless , parenchymatous with starch . Upper – air chamber, chloroplast. 3 Riella

4. Targionia Ribbon shaped. Sparingly dichotomous. Abundant adventitious branches – ventral side. Air pores – encircled with 4-6 concentric rings of cells. Monoclea Largest- thallose gametophyte – Monoclea fosteri . 2-3 times dichotomously branched. Chloroplast – dorsal epidermis. Antheridia – sessile receptacle. Archegonia – hood like sheath. Marchantia Jungermannials Leafy liverwort. Simple thallose type or foliose – stem and leaves. Antheridium – globose. Archegonial – neck has 5 vertical rows of cells. Pellia Porella Prostrate, dorsiventral, leafy axis. 3 rows of leaves. 2– lateral rows – dorsal side, 1-ventral side – amphigastria. 5 6

5. Topic PARAPHYSIS Anthocerotopsida Bryopsida Hornworts Small and distinct group Sporophyte – indefinite growth meristem at the base of capsule. Takakia Erect and radial Leaves - irregular –all sides as pairs. Rhizome without rhizoids. Gametophyte – thallose , lobed, radially dissected, dorsiventral, smooth walled rhizoids. Mucilage cavity on ventral surface. Single chloroplast with central pyrenoid. Sex organs are sunken in the thallus. Filamentous or simple thallose protonema Gametophore Rhizoids present – multicellular and diagonal cross walls. Stem – erect and prostrate. Leaves – sessile, single midrib, spirally arranged. Sex organs are in clusters. Perigonial – Antheridia Perichaetium - Archegonia Polytrichum Epidermis , hypodermal strands, endodermis and pericycle. Central cylinder has complex tissue differentiation - 7 8

6. Leptoids – resembles sieve cells Hydroids – water conducting tissue Steroids – supporting tissue EVOLUTIONARY THEORY Three Major Evolutionary Lines Are Recognizable Among Bryophytes 1. The Progressive Evolution Theory: This says that the first Bryophytes were of the simple thallose type with simple sporophytes, the complex forms developed by Progressive Evolution. 2. The Regressive Evolution Theory: This says that some erect, more complicated form was the first Bryophyte evolved, other forms, then developed by reduction in different lines 9 10

7. Bryophyte Structural organization and evolution of sporophytes Sporophyte Sporophyte Diploid generation Devoid of rhizoids Depends on gametophyte Spore production and dispersion Sperical - Riccia Capsule, foot – Corsinia Foot, seta and capsule – Marchantia

8. Sphaerocarpos sporophyte 14 13 Progressive sterilization - Bower Progressive elaboration and complexity of sporophyte Theory of Sterilization Progress in sterilization of potent fertile cells. Support in nutrition, support & dispersion. Riccia sporophyte Least amount of sterile tissue Entire embryo forms the spore producing capsule Dehiscence absent Lower part of young sporophyte becomes sterile and forms small bulbous foot and a very short seta. Targionia sporophyte Foot – large, bulbous Seta – long Half sporogenous cells from elaters. Marchantia sporophyte Half embryo – hypobasal region – sterile Sterile cells – foot, seta apical cap and elaters. Sphaerocarpos

9. Reduction theory 16 15 Epibasal half – entire sporophyte (foot & seta) Central mass of sporogenous cells – capsule base remain sterile - elaters Pellia sporophyte Anthoceros sporophyte Complete sterilization at center Entire endothecium remain sterile - columella Funaria sporophyte Major portion of the sporophyte remains sterile to form foot and seta.

10. Bryophyte Economic Importance Of Bryophytes Bryophytes as fuel Importance

11. Moss industry 20 19 Horticulture uses Bryophyte products Growing ornamental plants

12. Medicinal uses Role of bryophytes in different ways Polytrichum 21 22

13. Bryophyte Structural organization and evolution of gametophyte and sporophyte Given notes Economic importance of bryophyte Slideshare Economic importance of bryophytes - Khwaja Mahnoor https://www.slideshare.net/khawajamahnoor/economical-importance-of-bryophytes References 24

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