Bis2CF10.Lecture16

Bis2CF10.Lecture16 - Lecture 16 ORIGIN OF VASCULAR PLANTS...

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Unformatted text preview: Lecture 16 ORIGIN OF VASCULAR PLANTS Last: origin of land plants, life cycle Innovations within nonvascular land plants Innovations of vascular plants Ancestral morphology and its implications Next: early vascular lines, origin of leaves and roots 1 Outgroup streptophytes Land plants = Embryophytes Liverwort Moss Charales Hornwort Vascular plant (fern) leaves on gpt stomata Coleochaete branched spt tracheids green sporophyte cuticle rhizoids mycorrhizae alternation of generations: origin of sporophyte antheridia and archegonia sporangia air-dispersed spores: sporopollenin wall 2 phragmoplast, branched filaments, apical growth (meristems), oogamy Alternation of generations in nonvascular land plant (moss) Gametophyte (“gamete plant”) Gametangia (“gamete containers”) spore tetrad sporopollenin wall SPORES biflagellate SPORES Sporophyte (“spore plant”) Sporangium (“spore container”) DELAY OF MEIOSIS Land plants = embryophytes 3 Land plants = Embryophytes spt Liverwort Moss sporangium Hornwort Vascular plant (fern) leaves on gpt stomata spore branched spt vascular tissue green sporophyte archegonium antheridium cuticle rhizoids DELAY OF MEIOSIS mycorrhizae alternation of generations: origin of sporophyte antheridia and archegonia sporangia air-dispersed spores: sporopollenin wall 4 “bryophytes,” nonvascular plants Elaboration of sporophyte Reduction of gametophyte 5 Conocephalum Thalloid liverworts Marchantia sporophytes Leafy liverworts 6 Bazzania Monoclea: the world’s largest liverwort Waipoua, Aotearoa 7 Conocephalum Moss (Polytrichum) Sporangia Liverworts “Leaves” on gametophyte Hornwort (Anthoceros) 8 Bazzania Moss (Polytrichum) Hornwort Anthoceros Sporangia “Leaves” on gametophyte Stomata (singular = stoma) Hornwort (Anthoceros) guard cells 9 Lycopodium Aglaophyton Anthoceros Moss (Polytrichum) sporangia “Leaves” on gametophyte 10 Sphagnum sporophytes Sphagnum (peat moss) 11 12 Peat bogs, Canada, Ireland “bryophytes,” nonvascular plants Hornworts sister to vascular plants 13 “bryophytes,” nonvascular plants Hornworts sister to vascular plants Stomata X 14 Land plants = Embryophytes spt Liverwort Moss sporangium Hornwort Vascular plant (tracheophytes) leaves on gpt stomata spore branched spt vascular tissue green sporophyte archegonium antheridium cuticle rhizoids DELAY OF MEIOSIS mycorrhizae alternation of generations: origin of sporophyte antheridia and archegonia sporangia air-dispersed spores: sporopollenin wall 15 Early Devonian landscape (400 MY) 16 Trunk of Late Devonian tree (375 MY) Early Devonian landscape (400 MY) 17 Lower Devonian sediments Gaspé, Québec: 400 MY Compressions of early vascular plants 18 Rhynie Chert Early Devonian, Scotland: 400 MY “Rhyniophytes” Thin section of chert (SiO2, silica) sporangia aerial stems 19 horizontal creeping stems = rhizomes Early Devonian “rhyniophyte” “Typical” angiosperm apical meristem terminal LEAF Flat, lateral, determinate, photosynthetic aerial stems STEM Radial, grows upward, indeterminate, produces leaves Branch (new stem) from axil of leaf horizontal rhizomes ROOT Radial, grows downward, indeterminate, absorptive 20 (root hairs, mycorrhizae) Anatomy of “rhyniophytes” Stomata cortex (parenchyma) Lycopodium Recent Aglaophyton Devonian Anthoceros Recent rhizome epidermis with cuticle rhizoids 21 Rhynia stem cross-section Anatomy of “rhyniophytes” Taylor et al. 1995 - mycorrhizal fungi in Aglaophyton 22 Anatomy of “rhyniophytes” cortex (parenchyma) Xylem: conducts water Phloem: conducts sugars, etc. epidermis with cuticle 23 Rhynia stem cross-section Anatomy of “rhyniophytes” Xylem of Rhynie Chert plant Xylem: conducts water Phloem: conducts sugars, etc. Tracheids of living fern 24 Red = secondary walls with lignin FUNCTION OF XYLEM AND PHLOEM stoma Xylem Phloem rhizoid/root hair xylem water molecule 25 Reproduction in “rhyniophytes”: sporophytes sporangium Aglaophyton tetrad of spores tetrad scar spores 26 Reproduction in “rhyniophytes”: gametophytes antheridia archegonia 27 Sporophyte Vascular plant (fern) Dominant sporophyte generation Gametophytes & attached sporophytes 28 ...
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This note was uploaded on 04/19/2011 for the course BIOLOGY BIS 2C taught by Professor Doyle during the Fall '10 term at UC Davis.

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