Despersion Of Seed & Fruit

Despersion Of Seed & Fruit :-

From The Dehisense Fruit Seed Are release & Disperse Automactically , But In Case Of Indefiscent All fuit Automactically Break & disperse itself , They Disperse In That Manner,
As they get proper Light , proper nutrient & Favour evolution of Species . Because seed Does not have locomotary Organ , So they require Some agency for dispersion like some time eplosive mechanism

@ Types Of Dispersion of Seed :-
They Are Mainly of two type :-

They Are Mainly of two type :-

1.) Autopory :-

in these dispersion of seed are happen automactically or plant itself
2.)
Here dispersion of seed are happen by some kind of agency , which are mainly of following type :-

i) Anemophory :-

In these dispersion of seed are happen by agency of wind, which are of many kind , for anemophory plant seed adapt some feature are
- light weight
- minute seed
in such type of plant seed flow away long distance by wind current Ex:- Seed of orchid are smallest in plant having weight 0.004 gram weight , they carried by wind sometime 1000 km away 

@ Modification in Anemophory :-

# Wind Seed & Fruit :-

In Some Plant seed & fruit membranous wing like structure found, which take seed away into air Ex :- maize

# Parachut like appearance :-

In Some fruitParachut like modification persistant calyx are found , Ex :- seed of compositae 

# Pappus :- 

Hair Like structure development from persistent calyx in member of compositae family

# sensor mechanism :-

In case of opium fruit, opium fruit below the stigma small pore are found , which allow seed to disperse at a time , when fruit swing in air Ex :- poppy

# Rolling Mechanism :-

Founf in carthamus, Amaranthus,chenopodium in which all plant dry up, after bearing seed & fruit get uprooted by wind & roll over the ground & that's why seed disperse , these type called tumble mechanism

ii) Hydrophory :-

In these dispersion of seed are happen by agency of water , in such type plant floating device or protective covering are found
Ex :- 
# In Case of coconut mesocarp,became fibrous so fruit become vary light & it can swin easily in water
# In lotus hydrphory are found, in lotus flower thalamus seed are embedded their , which are very ligt swim over water & dispersed

iii) Zoophory :-

In these dispersion of seed are happen by agency of Animal or Sometime man also, 

@ Modification In these :-

- fruit having spike,hook & anthium, when any animal came near these plant , by hook or spike these plant seed are attached to animal fur or skin ,which carry them long distance sometime, in some cases sticky gland also present in these plant
- Some plant produce fleshy or raw material
- Human traveller carry some ornamental or commercial plant for ornamental or any use , by which their seed are disperse

SEED

SEED :-

Contain embryo with Future miniature plant, during development of seed
- Zygote convert into embryo
- triploid endosperm nucleus into ensosperm
- New Callous of ovule used up Sometime remain in form of thin layer called perisperm
- Outer integument dry up convert into testa (seed coat)
- Inner integument during development convert into thin papery layer called tagmen

NOTe :- 

Sometime seed are non-endospermic in nature ( or albuminari), due to it endosperm totaly utilized in this type seed store food in cotyledone
# When food is stored insideendosperm called endospermic seed or albuminous seed
# when food is store inside endosperm, but not in cotlydone called non-endospermic seed Ex :- maize, wheat, cater
* Dicot are non-endospermic seeds :- which may be of kidney shaped
* monocot are endospermic seed Ex :- Maize

DEVELOPMENT OF DICOT EMBRYO

DEVELOPMENT OF DICOT EMBRYO :-

There are mainly some steps by which all the development are occur are :-
- Firstly, mature zygote get enlarge in large 
- then this zygote Divide Into two cell By unequal division , in which upper Cell called Vasicular cell or primary suspensor cell & Lower cell called primary embryonal cell
- Now embryonal cell redivide form two cell, And Vascicular cell remain as such , which at last act for absorption
- now many division occur in embryonal cell , which form suspensor cell (may be of 6-18 celled) , but woith this one cell remain as such, which enaleges
- this cell enlarge & divide to form four cell stage called Quardant stage, then 8 cell stage called octant stage , then 16 cell stage called pro-embryo or glomerular embyo

Note :- The cell with present between suspensor & Pro-embryo called hypophysis cell, which is triangular in shape
- Now pro-embry slowly converted into heart shaped embryo, which having centrally located meristem cell , which begun to form
- after that these pro-embryo elongate & get mature to form mature form, which having pleurone at centre , plumule between two cotlydone , dermatogen layer at outer side & pedicle
- At Last, Fully development two cotlydone formed , which having vasicular cell or Hausterial cell uppermost side, many suspensor cell , then after root cap , two cotlydone in their centre plumule are present & tip of this called embryonal node
Note :- Distance between Root cap to plumule called hypocotyl
- Distance between plumule to embryonal node called epicotyl

DEVELOPMENT OF MONOCOT EMBRYO :-

These also occur in many steps as follow are :-
- Firstly, mature zygote get enlarge in large
- then this zygote Divide Into two cell By unequal division , in which upper Cell form Suspensor cell , which at micropylar end & another one called emnryonal cell
- Now Suspensor cell remain such as & embryonal cell divide into three divion which form upper (basal ) cell, middle (basal cell) & Lower embryonal cell or terminal cell
- Now middle cell divide to form globular like structure , with terminal cell at tip of these globular
- Some division occur in these globular cell , which form radicle layer, hypocotyl cell layer , plumule cell & at last cotlydone which form by terminal cell
- Now after maturation one cotyledone form having suspensor cell, radicle hypocotyl plumule & one cotyledone

Post Fertilization Changes

Post Fertilization Changes :-

After Double Fertilization stamen, petal, style,stigma are get dry , but sometime it remain they persist 

Post fertilization changes occur in 4 steps :-

1. Development of endosperm from primary Endosperm nucleus (PEN) 
2. Development Of Embryo from zygote
3. Development Of Seed from ovule
4. Development Of Fruit From ovary

1. Development of endosperm from primary Endosperm nucleus (PEN) :-

After Formation of Primary Endosperm nucleus , during process of seed formation, endosperm is a place where food is store for development of embryo & futher production, Primary endosperm nuvcleus is 3n In nature .
# On bases Of 1st & other subsequent Division Of primary endosperm nucleus is 3 Type :-

i) Nucleaur Endosperm :- 

- Here After entry of POllen tube , one nucleus fuse with egg & 2nd one fuse with POlar nuclei form PEN (primary endosperm nucleus)
- Now Triplod 3n PEN (primary endosperm nucleus) , having free Nuclear Division. Which form many Cell
- After Cell Division , all cell pushes outward , & makes a large central vacoule
- Now Cell Wall Formation take Place, & endosperm formed
- Ex :- Acalypha
* Special character is that it having free nuclear cell division

ii) Cellular Endosperm :-

- Here After entry of POllen tube , one nucleus fuse with egg & 2nd one fuse with POlar nuclei form PEN (primary endosperm nucleus)
- PEN (primary endosperm nucleus) Divide by transverse division & 2 cell Are Made with cell wall
- Now after 2 cell it divide into many division which make 4 to 8 cell with cell wall , Which form cell in linear arrangement & makes Cellular Endosperm
- Ex :- Pitunea
* Special character is that it having many cell wall division

iii) Halobial Endosperm :-

- Here After entry of POllen tube , one nucleus fuse with egg & 2nd one fuse with POlar nuclei form PEN (primary endosperm nucleus)
- Here PEN cell divide form 2 cell , in which one cell is Bigger than Other, The bigger cell is present at Micropylar end
- Free Nuclear Cell Division occur in Bigger cell which Form Many Cell, After that all cell pushes outward , & makes a large central vacoule
- Simultaneously small cell which present at chalazal end Divide form 2-3 cell form Hausterian Cell , Which act as for attachment
* Special character is that it having Haustein cell division

Double Fertilization

Double Fertilization :-

- these Type of Pollination occur only in Angiosperms

- Role Of Recognition Factor :-

These are the factor which decide acception & Rejection of pollen grain
* If it is Accepted , Then inner intine form hydrolytic enzyme, Which eat cell of style & make passage for intine
* In Angiosperms , Siphonogamy (Pollen tube carried male gamete to the egg ) type pollination found
- Pollen tube entery from Micropylar side is of Three type :-

i) Progamy =

 Here, pollen tube enter from micropylar side

ii) Chalazogamy = 

Here, Pollen tube enter from chalazal side

iii) Meizogamy =

 Here, pollen tube enter from lateral side

- Process Of Double Fertilization :-

These process is described by Mausachain in 1818 in fritillaria & lilium type plant
According to double fertilization , two male gamete , one synergids dis-organise at time of entry of pollen tube & provide site for entry of pollen grain, Now 1st male nucleus fuse with egg Called generative ferilization & Syngamy & after Symgamy Zygote is produced which further developed into embryo
Now 2nd male nucleus fuse with secondary Nucleus (polar Nuclei) , These process called vegetative fertilization , which is triploid (3n) in nature , these process is called fertilization

Pollination

Pollination :-

Transfer of pollen grain fom anther to receptive stigma take place by different agency , these are mainly

1. Self Pollination :-

It involve transfer of pollen grain from anther of flower to stigma of same plant , these are mainly 2 type :-

- Autogamy :-

In These transfer of pollen grain to same flower stigma take place , These Are mainly two type :-

~ Cleistogamy :-

it consist two word "cleisto=Close" & "Gamy=Marriage", In These Transfer Of pollen grain , in which flower neverr open to assure self polination

~ Homogamy :-

Both anther & Stigma Mature At same Time to perform Self pollination , Come close to Each other By Folding & Bending & Perform Homogamy , Ex :- Potato

~ Bud Pollination :-

In These type, Pollination is done before opening the flower

2. Geitonogamy :-

iT Consist of two word "Geitono=Labour" & "gamy=Marriage" , In These Type of pollination anther pollen is transferred to another flower on the same plant. 

@ Disadvantages Of Self Pollination :-

* Progeny Goes to Weak Generation after generation
* Less Changes To produce New Species & New Variety

@ Cross Pollination (Allogamy) :-

Transfer Of pollen Grain one Plant anther to Stigma of another flower

@ Characteristics Why Cross Pollination Occur :-

- Herkogamy :-

When Some Mechanical Barrier Are Found , Which prvent Pollination , Ex = Pollinea

- Dichogamy :-

In These Type, Stigma of gynoecium & Pollen Grain From anther Mature at different Type to avoid self pollination , These are of two type :-

~ Protogamy :-

In these type of Dichogamy Gynoecium mature first , Ex= Bajra

~ Protandary :-

In These type of Dichogamy Anther mature first , Ex :- maize

- Self Incompability :-

In These type, Pollen grain of flower fall on stigma but not Germinate . Due to some deposition of Some cementing Material (Callose) in stigma . That's why pollen tube cannot Penetrate stigma

- Male Sterlity :-

In Some Plant,Pollen Grain Become Non-functional so, Cross pollination always Occur In Bisexual Plant

@ Vector or Agent which Help in Pollination :-

There Are mainly two type of Factor

i) Abiotic factor :-

These Are Non-Living Factor , Some Example of these are :-

~ By Wind (Anemophily) :-

Pollination in which wind act as vector For Pollination,

# Charcter for Wind Pollination :-

- Plant Having Colourless, Nector less, Unisexual Character
- Male flower Are More Abundant ,
- pollen grain Are small , Dusty, Light & Produce In Huge Quantity
- In These Flower Are well Exposed,
- Stigma Are Larged Hairy

# Gum POwder Mechanism :-

In Urtica , Flower Burst Suddenly & POllen grain Come Into air

two type :-

~ By Water (hydrophily) :-

Pollination in Which Water act as Vector For Pollination

ii) Biotic Factor :-

These are The Living Factor , which aact as vector for pollination are :-

~ By Bird (Ornitophily) :-

Pollination in Which Bird act as Vector For Pollination

~ By Insect (Entomophily) :-

Pollination in Which insect act as Vector For Pollination

~ By Bat (Chiropterophily) :-

Pollination in Which bat act as Vector For Pollination

Types of Embryo Sac

Types of Embryo Sac....

Monosporic Embryo Sac :-

Embryo Sac Developed From One functional Megaspore Nuclei

Bi-sporic Embryo Sac :-

Embryo Sac Developed From two functional Megaspore Nuclei

Tetrasporic Embryo Sac :-

In Which Megaspore Mother Cell divide By meiosis & form 4 Haploid Daughter Nuclei & wall Formation Absent Between All four Nuclei Participate Equally in formation , So equivalent to 4 megaspore Called Tetrasporic
Acc. To P.Maheshwari In 1950 , tetrasporic Embryo sac is of 7 Type :-
- Adoxa
- Pepromea
- Plumbegella
- Fritillaria (Very Important)
- Drusa
- Penea
- Plumbago

Allium & Fritillaria Type (tetraspore) :- 

in Which Megaspore mother Cell divide By meiosis