BOT 3: Bryophytes

8/8/2019 BOT 3: Bryophytes

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ES:NON-

VASCULAR

PLANTS tjmedina


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KINGDOM PLANTAE

Terrestrial organismsEukaryotic

PhotosyntheticOrgan formingWith diplohaplontic life cycleHeteromorphic gametophyteand sporophyte generations

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Closely related to the greenalgae: Charophyceae: Chara andColeochaete

Cellulosic cell wall

Chl a and b as pigments

Starch as stored food

Phragmoplast type of cytokinesisSimilarities in nuclear genes and rRNA

KINGDOM PLANTAE

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Adaptations to the life on land:Sterile jacket of cells surrounding

egg-sperm producing structures

Protective layers of cells coveringspore producing structures

Protected embryo

Waxy coating cuticleSpecialized cells for water and food

conduction

KINGDOM PLANTAE

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KINGDOM PLANTAE

Kingdom Plantae

VascularPlants

Non-vascularPlants

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NON-VASCULAR PLANTS:BRYOPHYTES

earliest land plants

well-adapted to moist habitats (low-lying)

the only land plants that have a dominant

gametophyte (the sporophyte is parasitic tothe gametophyte).

Sporophyte

(2n)

Gametophyte (n)

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lack Vascular Tissue

Impact on Structurea few have modified water transport cells, calledhydroids and solute conducting cells, called

leptoids , but this is rare.size restriction depends on cell to cell diffusion for

transport

often grow in prostrate masses or clumps (Novascular tissues for strength for upright growth)

attach to substrate with rhizoids which anchor(no true roots)


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Three divisions:

Hepatophyta (Liverworts)

Anthocerophyta (Hornworts)

Bryophyta (Mosses)


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DIVISION HEPATOPHYTA Sporophyte

non-photosynthetic, parasitic on the gametophyte (foot)

with spores (with elaters for dispersal); borne on acapsule-seta;

Gametophyte green, small, flat, ribbon like;

no xylem and phloem, cuticle and stomata

two forms: thallose hepatics- many cells thick; dorsal part is

chloroplast rich and ventral part is colorless with rhizoid leafy hepatics- well-branched and form small mats;

arranged in 3 ranks: a pair of lateral appendages and amedian appendage (amphigastria); leaf no midrib or costa.

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Reproductionasexually: by fragmentation (wherein older

central portions die leaving growing tips as

new individuals), and gemmae formation(multicellular asexual propagule, stored ingemmae cups)

sexually: gametophyte produces antheridiaand archegonia

DIVISION HEPATOPHYTA

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ThalloseLiverworts

LeafyLiverworts

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Thallose LiverwortsMarchantia


With gemmaecups

archegoniophore

antheridiophore

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Thallose LiverwortRicciaCyathodium


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Leafy liverworts Plagiochila

Bazzania

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Sporophyte elongated, horn-like, photosynthetic structure

arising from the gametophyte

cylindrical sporangium; spores with

pseudoelaters (slightly coiled strands) Gametophyte resemble thallose hepatics

each cell has a single chloroplast and pyrenoid

with stomatawith extensive internal cavities filled with

mucilage, and occupied by cyanobacteria(Nostoc).

DIVISIONANTHOCEROPHYTA

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Reproductionasexually: spore formation in

capsules (with reduced or no seta)

sexually:gametophyte(monoecious)produces archegonia

and antheridia (clustered) on thedorsal side; the sperm isbiflagellated and facilitated by water.


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Anthoceros


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Sporophyteonly the female moss produces an erect

sporophyte (at the terminal end of thestem exhibiting a long seta and shortcylindrical capsule) and bears spores

Gametophytegreen, leafy (occur in 2 or 3 ranks; with

costa or midrib) and generally, uprightwater flows by simple diffusion (epidermis,

cortex, medulla); for the familyPolytrichaceae: hydroids and leptoids arepresent in the medulla.

DIVISION BRYOPHYTA

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2 patterns of growth:cushiony- gametophyte is erect and

sporophyte is terminal

feathery- gametophyte is creeping, sporophyte

lateral.

Reproductionasexually: spore formation in capsules

(with calyptra, operculum and peristome

teeth)sexually: gametophyte (dioecious)

produces archegonia and antheridia(biflagellated sperm)

DIVISION BRYOPHYTA

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DIVISION BRYOPHYTA

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Cushiony mossMnium

Fissidens

Pogonatum

DIVISION BRYOPHYTA

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Feathery mossesThuidium

Sphagnum

DIVISION BRYOPHYTA

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ROLE OFBRYOPHYTES pioneer plants, growing on bare rock and

contributing to soil development.

in mountain forests they form a thick carpet,reducing erosion.

in forest ecosystems they act like a spongeretaining and slowly releasing water

provide habitat for other plants and smallanimals as well as microorganisms like N2-

fixing cyanobacteria

can serve as bioindicators of pollution andenvironmental degradation

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REFERENCES

http://www.cavehill.uwi.edu/FPAS/bcs/bl14ap

http://www.microscopy-uk.org.uk/mag/index

http://scidiv.bcc.ctc.edu/rkr/Botany110/lectu

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http://www.cavehill.uwi.edu/FPAS/bcs/bl14apl/bryo1.htmhttp://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjul98/jpmoss.htmlhttp://scidiv.bcc.ctc.edu/rkr/Botany110/lectures/bryophytes.htmlhttp://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjul98/jpmoss.htmlhttp://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjul98/jpmoss.htmlhttp://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjul98/jpmoss.htmlhttp://scidiv.bcc.ctc.edu/rkr/Botany110/lectures/bryophytes.htmlhttp://scidiv.bcc.ctc.edu/rkr/Botany110/lectures/bryophytes.htmlhttp://scidiv.bcc.ctc.edu/rkr/Botany110/lectures/bryophytes.htmlhttp://scidiv.bcc.ctc.edu/rkr/Botany110/lectures/bryophytes.htmlhttp://scidiv.bcc.ctc.edu/rkr/Botany110/lectures/bryophytes.htmlhttp://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjul98/jpmoss.htmlhttp://www.cavehill.uwi.edu/FPAS/bcs/bl14apl/bryo1.htm


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BOT 3: Bryophytes