Characteristic of Pteridophyte:-Occurance:

-Sporophyte development:

-Sporophyte part:

-Reproduction:

-Development of sporangia:

-Gametophyte:

-Gametophyte type:

-Sex organ:

-Antheridia:

- Archegonia:

- Fertilization:

- Embryo:

Life cycle of Pteridophyte:-Two distinct generation.-sporophyte---- sporangia---- spore mother cell----- spore.-homosporous pteridophyte---- spore germination--- gametophyte----bears female gamete---- egg and male gametes-----sperm--------fertilization--- deploid zygote--------- germination------------ sporophyte.

-In heterosporous pteridophyte: 2 kinds of spore, smaller---micro/male spore.-large spore-megaspore/ female spore.-microspore germinate--- male gametophyte; megaspore----female gametophyte.-male gametophyte----male gamete or sperm.-female gametophyte---- egg.-fertilization-------- zygote--------- sporophyte.

Apogamy:Apospory:

Affinities of Pteridophyte with Bryophytes: Similarities:1. Terrestrial habitat.2. Reproduced asexually by means of spore.3. Sex organ: antheridia and archegonia.4. Sterile jacket on sex organs.5. Male gamete i.e. sperm are cilliated.6. Fertilization take place in water (amphibians of plant kingdom).7. Zygote retain within wall of archegonia—germinate ---- embryo.8. Young sporophyte depend on gametophyte for nourishment.9. Exhibit heteromorphic alternation of generation.Dis-similarities:1. Pteridophyte-Sporophyte; Bryophyte-gametophyte.2. Pteridohyte-sporophyte dominent and independent; Bryophyte-

gametophyte dominent and independent.3. Sporophyte- true root,stem and root; sporophyte depend on

gametophyte- foot seta and capsule.4. Sporophyte- well developed vascular sytem; absent in bryophyte.5. Pteridophyte root are present; Bryophyte instead of root rhizoids

present.

Affinities with gymnosperm: similarities1. Sporophyte:2. Alternation of generation.3. Leaves.4. Absence of vessels.5. Phloem lack companion cells.

Disimilarities:1. Roots2. Cambium3. Neck canal and venter canal.4. Megaspore retain in megasporangium.5. Seed in gymnosperm.6. Pollen grain germinate to pollen tube in gymnosperm.

Marsileales:-Single family marsileaceae.-Three genera: Marsilea, Pilularia andRegnellidium.-Marsilea:

-Sporophyte having slender creeping, dichotomously branchedrhizome, roots and leaves.-At each node bears 1-2 adventitious roots and upright leaf of flexiblepetiole and lamina divided in to four leaflet.-Young leaf circinate.-Reproductive str. Is bean like sporocarp born on short stalk, insertedabove the base of petiole.

-Petiole:-Outer epidermis, cortex and stele.-Epidermis is composed of single layerrectangular cell.-Cortex is differentiated in to outeraerenchymatous and innerparenchymatous region.-Cells of inner cortex having starch grain.-Stele is surrounded by endodermis andpericycle.-Two arm of xylem curved away fro eachother, each xylem arm comprises 1-2metaxylem and few protoxylem at boththe end.

Root:-T.S. of root shows three distinctregion- epidermis, cortex and stele.-Single layered epidermis iscompactly arranged cells.-Cortex is differentiated as outeraerenchymatous, middleparenchymatous and innersclerenchymatous regions.-Stele is surrounded by layer ofendodermis and pericycle.-Xylem is diarch and exarch.-Two metaxylem at center andprotoxylem towards the periphery.

Reproduction:By spore:Marsilea is heterosporous, micro andmega sporangia born on bean shapedsporocarp.-Sporocarp is flattened bean shaped,spherical to ovoide, stalked str.,inserted a short distance above thebase of petiole.-In vertical longisection of sporocarphaving micro or megasporangia.-Megasporangia seen at mediansection and microsporangia seen attangential section.-Around the sori a gelatinous ring isform.

-In Horizontal longitudinal section: twoalternating rows of sori seen.-Each sori having vasculature trace andenclosed by indusium.-On the crest of receptacle born singlemegasporangia and on either side aremicrosporangia.-gelatinous ring at two end and one endthere is stalk bundle.-In Vertical transverse section: having tworows of sori attached to receptacle andcovered with indusium.-Each sorus having one sporangia, with onemain bundle, lateral bundle and placentalbundles.-Cut portion of gelatinous ring are at twoends.

-The dry Sporocarp are like nut, capable of surviving long period ofdrought and remain viable up to 30-40 years .-Sporocarp open only in winter, splitting bivalve like, process initiated byabsorption of water by gelatinous ring which expand and free the sorifrom the wall of Sporocarp.- Broken gelatinous ring result in to worm like sporophore with numberof sori in two alternating rows.-Sori appear sac like str. And contained sporangia-The spores are of two type microspore and megaspores.

-Microspores: small globular shapeand triradiate ridge , 0.075- 0.06 mmin diameter.Nucleus is centrally placed with 1 or 2nucleoli, a large no. of starch grain.-Microspore germinate rapidly afterliberation from sporocarp.-The nucleus migrate to peripheryand first division is unequal, formingsmaller lense shape cell with scantycontent.-larger cells divide unequally andseries of division differentiate in totwo spermatogenous cells.-Each cell by succesive divisionproduces 16 multiflagellate spermswith prominent vesicle.

-The megaspore large ivory white paillatestr. Enclosed by gelatinous layer apex ofpapilla having traradiate marking.-First division produce small cells whichlies in papilla and larger basal celloccupies rest of spore, storing foodmaterial.-gametophyte produces only onearchegonium derived from apical cells.-Mature archegonium having 2 celledneck cells long with single neck canalcell.-The gelatinous sheath around themegaspore has opening at apex.

-Sperm trapped in the gelatinous sheath, pass downward toarchegonium through the opening in the sheath and swimming in spermlake.-The antherozoid fertilized with egg nucleus.-The first division of zygote is longitudinal followed by transverse.-Thus four celled embryo is established; upper two gives rise to leaf androot, lower two form stem and foot.

-The cells of archegonial venter divides and form sheath around thedeveloping ambryo called calyptra.-The calyptra remain covered the sporophyte till differentiation of firstleaf.- Calyptra split at tip and young sporophyte come out.

Salviniales:-Two families Salviniaceae and Azollaceae.-Two genera Salvinia and Azolla.-Both the forms are free floating Azolla with sixspecies and Salvinia with 10 species.Salvinia:-Salvinia has slender branched rhizome withoutroots, free floating plant.-At the node are born three leaves; two lateral arefloating and third one is submerged.-Submeged leaf is highly branched and covered withwaxy hairs, which trap the air and help plant to floaton the surface of water.-Lateral leaves laminate with reticulate venation andcovered with hairs.-Stem is siphonostelic with reduced vascularelement.Reproduction:-Sporocarp born in cluster on inner segment ofsubmerged leaf.- All sporocarp resemble in external appearance butproximal one or two are megasporangiate andremainder are microsporangiate.

-Sporocarp wall is two layered and with abundant hairs.-In each sporocarp there is eleveted receptacle bearing sporangia.-Megasporangiate sporocarp contain up to 25 megasporangia, microsporangiatehaving numerous microsporangia.-Microsporangium having slender stalk of single rows of cells, sporangialeptosporangiate with single layer tapetum, produce 64 trilet microspores.-Microspores are scattered in sporangium and surrounded by tapetal cytoplasm.-This alveolar mass is shed as unit called as massula.-In developing megasporangium are formed 32 spores all of which except onedegenerate.-Cytoplasm of degenerating megaspore and tapetal cells form vacuolate layeraroundthe megaspore called epispore or perispore.-On the apex it form pollen chember like cavity.-Microspore and megaspore release by decomposition of sporocarp wall.-Megaspore divides as small apical and large basal cell.

-Apical cell divide anticlinally forming two unequal cells leading to 2unequal segment .-Upper larger segment bears archegonia having neck cells andbinucleate neck canal cell.-Microspore germinate within massula, enlarge and form four celled str.Of which lowest small basal cell having prothallial cell of malegametophyte and two upper cells by succesive division, differentiate into two spermatogenous cells called as antheridium which for foursperms.-Embryogeny:-Fiirst division is longitudinal --- further division form octant stage ofembryo.-From basal cells foot is formed, from outer cells leaf and stem is arise.

Azolla:-Sporophyte is small size moss like leaves free floating rhizome withsubmerged roots.-Root born on lower side, close to the point of origin of branches.-Leaves arranged in alternate rows, each leaf has two lobes; upper aerialand lower submerged one.-Submerged lobe is one celled thick only.-Aerial lobe is more than one celled-thick and photosynthetic withstomata on both surface.-Upper epidermis has one / two celled hairs.-On the lower surface having live colonies of Anabaena

Stem Anatomy: Stem grow by means of anapical cell.-Cortex is five – eight celled thick and made upof thin walled parenchyma cells.-Vascular cylinder is siphonostelic withendodermis and pericycle.-Beneath the pericycle ring of xylemintterupted by leaf traces.-Phloem is better develop on the lower surfaceof stem.T.S. Root: Epidermis is surrounded by onecelled thick sheath.-Two layered cortex of large thin walled cells.-Cortex is followed by endodermis andpericycle of one layer each.-Stele is protostele consisting of only twometaxylem element with small protoxylemelement. -Four phloem element.

Reproduction:-Sporocarp are dimorphic bigger one is megasporangiate and smallerone is microsporangiate.-Wall of sporocarp is two layered.-Both the type of sporocarp are alike during early development.-An apical megasporangial initial develop on receptacle and below arisesporocarp wall.-Indusium develop more rapidly than sporangium.-Megasporangium has one cell thick tapetal layer and eight megasporemother cells.

During meiosis tapetum breaks down and 32 young megaspore form.

All of which one except one degenerate.Surviving megaspore enlarge and fill the cavity of sporocarp.

-Development of microsporangium is leptosorangiate.-Has formation of long narrow stalk, globose-Similarly there are eight spore mother cell and one cell thicktapetal layer.-During meiosis tapetum break down and 32 microsporeformed.

-Spore occupy peripheral region due to periplasmodial mass anddevelop tubular glochidia.-The mass is called as massula containing microspore.-Mature sporocarp micro as well as mega. sink to bottom in water.-Massula and megaspore released by decomposition of wall.-Germinating microspore form papilla, in the papilla it form singleprotruding antheridia.-Papillar cell divides and form cap and lower antheridium.-Eight spermatocyte produced, release sperm by softening of massula.

-The megagametophyte is hemisperical mass of 5-8 celled .-Form first archegonia similar to other ferns, forming 3-4 celled neckcells, small venter cell and large egg.-After fertilization zygote elongate embryogeny is typicalleptosporangiate fern.-First division is oblique, longitudinal and form quadrant resulting in tofour organ leaf stem, root and foot.