Bryophytes have three main classes: Hepaticopsida, Anthocerotopsida, and Bryopsida. Gametophytes vary in structure between classes from simple thallose forms to more complex leafy forms. The life cycle involves a dominant gametophyte phase that produces gametes and a sporophyte phase that is dependent on the gametophyte. The sporophyte evolves from a simple sac producing spores to more complex forms with sterile foot and seta structures that aid in spore dispersal. Bryophytes have economic importance as fuel sources from peat, in horticulture, and for traditional medicinal uses treating wounds, skin conditions, and insect bites.
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.
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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.
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5. Topic
PARAPHYSIS
Anthocerotopsid
a
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.
1. Filamentous or simple thallose
protonema
2. 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 -
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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
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8. Sphaerocarpos sporophyte
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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
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• 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.
Simplification of the dehiscence apparatus
Reduction of photosynthesis tissue in the
capsule wall.
Disappearance of stomata and intercellular
spaces.
Decreases in the thickness of the wall.
Gradual elimination of the seta and
subsequently the disappearance of the foot.
Progressive increase in the fertility of the
sporogenous cells
12. Medicinal uses
Skin
treatment
Help to cure
ringworms
disease
Use for
curing for
allaying
arising from
insect bites
Ash of moss is
mixed with
honey and fat
to treat cuts,
burns and
wounds.
Scabies,
acne etc,.
Role of bryophytes in different
ways
Seed beds
Food &
shelter
Pollution, Ph, acid
rain indicator
Soil conservation
Polytrichum
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13. Bryophyte
Structural organization and
evolution ofgametophyte and
sporophyte
Given notes
Economicimportance of
bryophyte
Slideshare
Economic importance of
bryophytes - Khwaja Mahnoor
https://www.slideshare.net/khawajamahn
oor/economical-importance-of-
bryophytes
Reference
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