Rhodophyta PPT BY :- Dr.Pinky Diwedi

1. Rhodophyta
B.Sc.Iyear,paper-I,unit-II
M.Sc.Isem.,Paper102,unit-II
Dr. Pinky Dwivedi

2. Red algae.Mostly marine.tropical & subtropical.
Plants multicellular Porphyridium-unicellular.
thallus- mono or polysiphonous.
Pigments- chl.a, chl.d,carotenoids, xanthophyll,
r-phycocyanin, r-phycoerythrin.
Resrved food-floridean starch.
pits are present on adjacent cells.
chromatophores- bound double membrane.
Motile cells-absent.
Sexual reproduction –oogamous.Male gametes-
spermatia, female gametes-carpogonia.
Life cycle – triphasic.

3. THALLUS
Unicellular-Porphyridium
Multicellular- filamentous- Goniotrichum
ribbon like or plate like-Porphyra
thallus is uniaxial or multiaxial, branching is
monopodial.
cell structure-eukaryotic.
cellwall- outer-pectinwith polysulphate esters.
Inner- cellulosic.
in Bangiales,Nemalionales,Cryptonemales,
Gigartinales- have single nucleus.

4. 831 genera,5250 spp. About 200 spp. –
freshwater. Batrachospermum, Lemanea-cold
fast flowing. Compsopogen- stagnant water,
they are bluish green while marine arered,
purple or voilet.
Parasitic spp.-Polysiphonia lanosaon
Ascophyllum nodosum.
Epiphytic- Choreocolax, Acrochaetium.
epizoic on sponges, molluscs.
most spp. Grow in deep sea.

5. Fritsch
Rhodophyta Eukaryota
Rhodophyceae Rhodophyta
Ceramiales Rhodophyceae
Rhodomelaceae Florideae
Polysiphonia viridi Ceramiales
Rhodomelaceae

6. Polysiphonia- marine, Attached to substratum.
Thallus- red, appears feathery, attached to
substratum –long, nonseptate, plate like
rhizoids- hapteron or holdfast.
Thallus- 2 types of filaments—Prostrate and
errect.
Three different types of plants develop in life
cycle-Gametophytic
Tetrasporophytic
Carposporophytic

7. Reproduction- asexual –Tetrasporic plant.
sexual- Gametophytic plant.
Gametophyte-Male and female plants are seprate,morphologically similar.
male sex organs-spermatangia.
female sex organ- procarp,flask shaped-basal part-carpogonium upper-
trichogyne.
Post fertilisation changes- after fertilisation many changes take place in
capogonium.
1.basal sterile filament initial divides 2 celled filament.
2.lateral sterile cells divide -4-10 cells.
3.supporting cell- upper end auxillary cell.-it has haploid nucleus.It
establishes connection with base of the carpogonium.
4. carpogonium-diploid nucleus divides into 2 , one migrates into auxillary
cell ,soon haploid nucleus degenerates.
5.Supporting cell & auxillary cell fuse and formsplacental element.
6.Upper part of auxillary cell forms gonimoblast initials- gonimoblast
filamentswith diploid nucleus. Their ends- carposporangium –
carpospores.