General characteristics

(1)

(2)

• ca 265 genera, 1500 - 2000 species

• multicellular thallus, attached to the surface

• marine, only 3-5 species in freshwater habitats

• rocky coastline – litoral, sublitoral (min. 0,6% of

residual light – up to depth of 260 m, but most

species are not shade-loving organisms)

• high primary production, DMS production

• economically and culturally important –

aquacultures, seaweed art

(3)

(4)

Plastids

• chl a, c

₁

,

c

₂

, β-carotene, fukoxanthin

Bacillariophyceae)

,

violaxanthin, dinoxanthin, diadinoxanthin

• discoid plastids, 1 or more pyrenoids

• heterokont structure

(5)

Plastids

2layered plastid membrane

nucleus

chloroplast ER

oil globules

(6)

(7)

Metabolism products

• storage products (chrysolaminaran, manitol)

• florotanins – stored in physodes, when oxidized,

they case brown colour of water

• iodine (0,03 – 0,3% of weight)

• organobromids – destruction of

ozone layer

• dimethylsulphopropionate – osmotic regulation

production of DMS (in parallel to haptophytes)

(8)

Cell wall composition

• alginates – salts of Alginic acid (gelatinous)



Na-alginates – soluble



Ca-alginates – insoluble

• cell wall structure



fibrilar component – cellulose, Ca-alginates



amorphous component – soluble Na-alginates

• fucoidane – mucilage surrounding cell wall



against dry off

(9)

Zoids

features similar to other heterokont groups heterokont flagella, mastigonemata four membranes, girdle lamella periplastidial reticulum photoreceptor

features typical for brown algae

lateral flagella insertion

flagella terminated by acronemates

(10)

(11)

Sexual reproduction

• diplohaplontic cell cycle, isomorphic and heteromorphic

• plurilocular zoidangia

(12)

(13)

Thallus structure

cell division types

(14)

Utilization of brown algae

• Scandinavia, Faroe Islands – grazing by sheep

• fuel, composting, roofs

• production of soda, potash, iodine (1930s)

(15)

(16)

Utilization of brown algae - food

(17)

Utilization of brown algae - food

(18)

Utilization of brown algae - food

(19)

Utilization of brown algae - alginates

(20)

Utilization of brown algae - alginates

(21)

Utilization of brown algae - alginates

(22)

farmaceutics, cosmetics

(23)

slim down diets – satiety

(24)

building materials

(25)

Utilization of brown algae - fucoidane

(26)

Utilization of brown algae

seaweed baths

(27)

Utilization of brown algae

alginate batteries

(28)

seaweed art

(29)

Systematics and diversity

• class Phaeophyceae, syn. Fucophyceae • ca 14 orders (van den Hoek 1995)

(30)

Phylogeny

• traditional concepts of phylogeny and taxonomy:

Ectocarpales

Sphacelariales

Dictyotales

Cutleriales

Laminariales

Fucales

G,S,iso G,S,iso G,S,iso G,S,hetero S,hetero S,hetero

(31)

Time-calibrated multigenic molecular phylogeny of Phaeophyceae

(32)

(33)

Dictyotales

• fan-shaped, parenchymatic thallus (2-3 layers of cells) • diplohaplontic cell cycle, isomorphic, always oogamy

(34)

Dictyotales

• true dichotomy, growth by division of apical cell • temperate, cosmopolitan species

(35)

sporophyte unilocular sporangia = tetrasporangia ♂ ♀ ♂ gametophyte ♀ gametophyte dark brown sorus – oogonia (unilocular gametangia) light brown sorus – antheridia (plurilocular gametangia)

(36)

Dictyota bartayresiana

(37)

Phylogenetic species structure of

Dictyota

in Europe

Tronholm et al., 2010, J Phycol 46: 1301-1321

(38)

(39)

(40)

Dictyopteris

Dictyopteris polypodioides

(41)

Lobophora

(42)

additional Dictyotales

• fan-shaped, slightly calcified thalli Padina pavonica

(43)

Padina pavonica

abundant Mediterranean species, shallow eutrophicated habitats

(44)

(45)

Sphacelariales

• branching multiseriate filaments

• diplohaplontic cell cycle, isomorphic or slightly heteromorphic • iso-, aniso- and oogamy

(46)

Sphacelariales

Sphacelaria rigidula • tiny brown tufts

• cosmopolitan, on rocks or epiphytic

(47)

Halopteris filicina

abundant Mediterranean species

Sphacelaria arctica

cold water, slowly growing, deep sea species Baltic – lower sublittoral

(48)

Fucales

• only macrothallus (S)

• diplont cell cycle, mostly oogamy

(49)

sporophyte (♀) _{sporophyte (}♂₎ receptacula ♀ conceptacula ♂ conceptacula oogonium (♀ gametophyte) antheridium (♂ gametofyt) receptacula → analogy to flowering plants

(50)

Fucales

Fucus – conceptacula

oogonia

(51)

Fucales

(52)

Fucales

(53)

Adaptation of Fucus serratus to decreasing salinity in brackish waters

Malm et al., 2001, Bot Mar 44: 101-108

two sites – Kattegat and Baltic, locally adapted popu- lations

critical stages of the life cycle at different salinities

(54)

Microspeciation of

Fucus

in the Baltic

Bergstrom et al., 2005, J Phycol 41: 1025-1038 Pereyra et al. 2009, BMC Evol Biol 9: 70

Fucus radicans

(55)

Ascophyllum nodosum – pesticides (against nematodes)

(56)

Fucales

Sargassum – warm temperate to tropical waters

(57)

Fucales

(58)

(59)

(60)

(61)

(62)

(63)

(64)

(65)

(66)

Cystoseiraceae – a Mediterranean lineage

upper sublittoral; stable, pristine, climax habitats

C. amentacea _{C. barbata}

(67)

Thibaut et al., 2005, Mar Pollut Bull 50: 1472-1489

(68)

(69)

(70)

(71)

(72)

Laminariales

• reduced microthallus (G) + foliose macrothallus (S) • diplohaplontic cell cycle, heteromorphic, oogamy, no

(73)

Laminariales

• very common species, submarine forests • alginate industry

• biodiversity centre – NW Pacific coast (Alaska – California) Laminaria

(74)

sporophyte

(fyloid, cauloid, haptera with rhizoides) sori unilocular sporangia (+ paraphyses) ♀ ♂ ♀ gametophyte ♂ gametophyte oogonia (unilocular gametangia) antheridia (unilocular gametangia)

(75)

L. saccharina L. hyperborea L. digitata

(76)

Laminariales

(77)

(78)

(79)

(80)

(81)

(82)

(83)

(84)

(85)

How good are the species of

Laminaria

?

(86)

How good are the species of Laminaria?

Erting et al., 2004, Eur. J. Phycol. 39: 243-256. ITS based phylogeny

(87)

Laminariales

(88)

Laminariales

(89)

(90)

Laminariales

(91)

Laminariales

Macrocystis – sublitoral, length up to 60m, weight 300 kg

(92)

Laminariales

(93)

D. anceps

D. ligulata

Desmarestiales

(94)

Ectocarpales

• simple, uniseriate filaments

(95)

Ectocarpales

• delicate, filamentous tufts

• very common, cosmopolitan species

(96)

Pylaiella littoralis

abundant cold water species, often in brackish waters, dominant as annual epiphyte in the Baltic

(97)

(98)

sporophyte ♂ ♀ ♀ gametophyte ♂ gametophyte plurilocular sporangia unilocular sporangia plurilocular sporangia plurilocular gametangia

(99)

Petroderma maculiforme (Ralfsiales)

(100)

Colpomenia

invazní druh mimotropických moří, původem ze severního Pacifiku Colpomenia peregrina

(101)

(102)

(103)

bývalé

Scytosiphonales

(104)

(105)

(106)

Adenocystis

(107)

Splachnidium

(108)

freshwater brown algae

• Pleurocladia, Heribaudiella, [Ectocarpus]

Ectoca

rpa

le