Pteridophyte reproduction - Christian Brothers...
Transcript of Pteridophyte reproduction - Christian Brothers...
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Pteridophyte reproduction
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Modified 17-13 (19-9) Embryophytes
“Bryophytes”
Rhy
nia
(Fos
sil)
Lyco
podi
ophy
ta
Pteridophyta
Transition to land
megaphylls
microphylls
Microphylls• One vascular trace
– No branching vasculature in leaf– Forms from protostele
http://28.media.tumblr.com/tumblr_lgpco8M9Ie1qa2aauo1_500.jpg
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Megaphylls– Branching vascular traces (veins) in leaves– Typically large
http://intro.bio.umb.edu/111-112/OLLM/112s99/phyla/plants/pterophyta.jpg
Are not always large.
Highly reduced megaphylls in Equisetales.
http://www.missouriplants.com/Ferns/Equisetum_hymenale_stems.jpg
Remember the STELES
Pteridophyta
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Stele modification in Pteridophyta
(a few with eustele)
ancestor had protostele,like Lycopodiophyta.
siphonostele
eustele
Protosteles
Lycopodiophyta
Siphonosteles
Most ferns, though, have siphonosteles with leaf gaps
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Eusteles
Equisetales—eusteles; convergent with seed plants.
Heterosporous ferns
Eusporangiate ferns
Equisetales
Modification of life cycle and reproduction in Pteridophyta
heterosporyendosporic gametophyte
Filicales
Equisetales
ancestor had dominant homosporoussporophyte with undergroundnon-photosynthetic gametophyte,like Lycopodiaceae
above-ground photosyntheticgametophyte
leptosporangia
above-ground photosyntheticgametophyte
Life cycles: above-ground photosynthetic gametophyte
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Heterosporous ferns
Equisetales
Eusporangiate ferns
Modification of life cycle and reproduction in Pteridophyta2. Leptosporangia
heterosporyendosporic gametophyte
Filicales
Eusporangiate ferns
ancestor had dominant homosporoussporophyte with undergroundnon-photosynthetic gametophyte,like Lycopodiaceae
above-ground photosyntheticgametophyte
leptosporangia
Life cycles: eusporangia vs. leptosporangia
Eusporangia: large1 to 1000’s of spores the basal (primitive) conditionwalls several cells thick found in most land plants
Leptosporangia: small64 spores
walls one cell thickhave annulus (thickened ring) grouped into sori (sing. sorus)only in Filicales and heterosporous ferns
Life cycles: eusporangia
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Life cycles: eusporangia in a eusporangiate fern (Botrychium)
Life cycles: leptosporangia
Life cycles: leptosporangia in Filicales
http://www.google.com/imgres?q=leptosporangia+in+filicales&hl=en&client=firefox-a&hs=HLb&sa=X&rls=org.mozilla:en-US:official&biw=748&bih=393&tbm=isch&prmd=imvns&tbnid=cDA5fNilc4DjaM:&imgrefurl=http://www.increasemyvocabulary.com/definition/of/leptosporangium/&docid=UL-NACsnDhf5jM&imgurl=http://farm3.static.flickr.com/2127/2263445746_61832fff71.jpg&w=500&h=375&ei=-2OsTtbwC62rsALHi8WADw&zoom=1
http://t0.gstatic.com/images?q=tbn:ANd9GcQ5dCnB8I61yQSkLGFZHRNK9szAhC4CieR19Yvgi78YQTs01RUurg
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Life cycles: leptosporangia grouped into sori in Filicales(Thelypteris)
http://t2.gstatic.com/images?q=tbn:ANd9GcR67ZaOrG_IZnVCTJlKNnzNb9xRzv2WRyzTn65QY9_qNAtdmw-d
Life cycles: leptosporangia grouped into soriin Filicales (Asplenium)
http://t2.gstatic.com/images?q=tbn:ANd9GcRa-R-awiaCHFAk1U2wWgyE4uwVRf-2z5DuiTDyJ5trjRpP7kMP
Heterosporous ferns
Equisetales
Eusporangiate ferns
Modification of life cycle and reproduction in Pteridophyta3. Heterospory and endosporic gametophytes
heterosporyendosporic gametophyte
Filicales
Eusporangiate ferns
ancestor had dominant homosporoussporophyte with undergroundnon-photosynthetic gametophyte,like Lycopodiaceae
above-ground photosyntheticgametophyte
leptosporangia
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Life cycles: heterospory
The life cycle of Selaginella is the same as that found in theheterosporous ferns and in the seed plants.
Live
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Embryophytes
“Bryophytes”
Rhy
nia
(Fos
sil)
Lyco
podi
ophy
ta
Pteridophytes
Transition to land
megaphylls
Equisetales: brief overview
--highly reduced megaphylls--eusteles--homosporous
i--eusporangia--above-ground photosynthetic gametophyte--strobili--hollow, jointed stems embedded with silica--one genus, Equisetum, about 15 species;
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Equisetales: Equisetum
Equisetales is the only fern group with strobili.Strobili are stems withmodified leaves–sporophylls—clustered on
http://www.sbs.utexas.edu/bio406d/images/pics/equ/Equisetum%20hyemale%20strob1.jpg
p p ythem. These sporophylls are often called sporangiophoreson Equisetum.
Equisetum: strobili
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Embryophytes
“Bryophytes”R
hyni
a (F
ossi
l)Ly
copo
diop
hyta
Pteridophytes
Transition to land
megaphylls
Eusporangiate ferns: brief overview
--megaphylls--protosteles--homosporoushomosporous--eusporangia--underground, non-photosynthetic gametophyte--includes Psilotales and Ophioglossales--7 genera, about 70 species
Eusporangiate ferns: Ophioglossales: Botrychium
What you’re seeing here is one leaf
http://www.rook.org/earl/bwca/nature/ferns/botrychium-multifidum-1sm.jpg
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Eusporangiate ferns: Ophioglossales: Ophioglossum
http://hengduan.huh.harvard.edu/fieldnotes/photos/show_image?image_id=1140
Eusporangiate ferns: Psilotales: Psilotum
http://t0.gstatic.com/images?q=tbn:ANd9GcRN0JvXD52gT892P9oJD7fNeMmehdMwcUyqLf8yF_ATVFbdvvh0
Live
rwor
tsH
ornw
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Mos
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To b
e co
nt.
Embryophytes
“Bryophytes”
Rhy
nia
(Fos
sil)
Lyco
podi
ophy
ta
Pteridophytes
Transition to land
megaphylls
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Heterosporous ferns: brief overview
--all aquatic--megaphylls--siphonosteles--heterosporousp--leptosporangia--endosporic gametophyte--includes Marsileales and Salviniales--5 genera, about 70 species
Heterosporous ferns: Salviniales: Azolla
http://nas.er.usgs.gov/XIMAGESERVERX/2007/20071004180006.jpg
Heterosporous ferns: Salviniales: Salvinia
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Heterosporous ferns: Marsileales: Marsilea
Live
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Embryophytes
“Bryophytes”
Rhy
nia
(Fos
sil)
Lyco
podi
ophy
ta
Pteridophytes
Transition to land
megaphylls
Filicales: brief overview
--megaphylls--siphonosteles (mostly) – few with eusteles--homosporoushomosporous--leptosporangia--above-ground, photosynthetic gametophyte--about 320 genera, 10,500 species
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Filicales: Dennstaedtia
Filicales: Pteridium
http://t2.gstatic.com/images?q=tbn:ANd9GcQSnzinzDmcXng7WDPh3-KaypqI3JJUDSxUWSbyCjSa91eTqQOzcg