The document discusses the floral structure of various plant families including cereals, legumes, and cotton. It provides detailed descriptions of the floral parts and their functions, as well as the morphology of flowers in families like grasses, legumes, and malvaceae. Examples of floral structures are given for crops like rice, wheat, maize, and cotton. The summary concludes that understanding floral biology and morphology is important for plant breeding and maintaining genetic purity.
seed is scientifically the mature embryo.
these powerpoint slides include the basic concepts of seed,its importance, parts of seed, composition,seed structure, seed development and embryogenesis.
seed is scientifically the mature embryo.
these powerpoint slides include the basic concepts of seed,its importance, parts of seed, composition,seed structure, seed development and embryogenesis.
The modes of reproduction in crop plants may be broadly grouped into two categories: asexual and sexual.
Sexual reproduction involves the fusion of male and female gametes, whereas in asexual reproduction new plants may develop from vegetative parts of the plant (vegetative reproduction) or may arise from embryos that develop without fertilization (apomixis).
Fertilization is the process of fusion of the female gamete, the ovum or egg and the male gamete produced in the pollen tube by the pollen grain. Fertilization in flowering plants was discovered by Strassburger in 1884.
Flowers are the reproductive structures of angiosperms. They vary greatly physically and are of great diversity in methods of reproduction. The process of fertilization in plants occurs when gametes in haploid conditions meet to create a zygote which is diploid.
The male gametes of the flower are transferred on to the female reproductive organs through pollinators. The final product of this process is the formation of embryo in a seed.
In this lesson you will learn about :
1) What is Fertilization?
2) The Pollen Grain (Male Gamete)
3) The Ovule (Containing Female Gamete)
4) Microsporogenesis and Megasporogenesis
5) Germination of Pollen Grain
6) Double Fertilization
7) Post Fertilization Events
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Plant fertilization is the union of male and female gametes (reproductive cells) to produce a zygote (fertilized egg)
Double Fertilization
Both the male gametes/sperms participate in sexual reproduction.
Two male gametes fuse with one female gamete wherein one male gamete fertilizes the egg to form a zygote, whereas the other fuses with two polar nuclei to form an endosperm
Triple fusion is the fusion of the male gamete with two polar nuclei inside the embryo sac of the angiosperm.
Porogamy - entry through the micropyle.
Chalazogamy - entry through the Chalaza
Mesogamy - entry through the middle part or the integuments
Steps leading to fertilization
Germination of the pollen grain:
Stigma function is to provide place of lodging and germination of the pollen grain after pollination.
Types of stigmas-
Wet stigmas
Secrete exudates like water and other nutrients
In the form of droplets on the stigma.
Exudates made up of a mix of water, lipids, sugars, amino acids, phenolic compounds.
Highly viscous and adhesive. Ex: Petunia, Zea etc.
Dry stigma
Do not secrete exudates Ex: Gossypium
Double Fertilization & Triple Fusion:
Both the male gametes are involved in the fertilization.
Fertilize two different components of the embryo sac - Double Fertilization
One fuses with the egg nucleus (syngamy) -> Zygote(2n)
second fuses with polar nuclei -> primary endosperm nucleus (PEN).
Involves fusion of three nuclei - Triple fusion -> Endosperm(3n)
Pollen tube in the synergids:
Entry only through micropyle. Guided by oburator
Presence of chemotropic substances
Collapse of one the synergids prior to entry of the pollen tube.
Pollen tube in the synergids:
Entry only through micropyle. Guided by oburator
Presence of chemotropic substances
Collapse of one the synergids prior to entry of the pollen tube.
Discharge of pollen tube contents (two male gametes, vegetative nucleus and cytoplasm) into the synergids.
Disorganization of tube nucleus
Polyspermy &Heterofertilization
Heterofertilization - Type of double fertilization in plants in which endosperm and embryo are genetically different.
This happens when two different sperm nuclei from two different pollen tubes happen to enter the same embryo sac.
Dr. T. Annie Sheron
Annie Sheron
Kakatiya Government College
The modes of reproduction in crop plants may be broadly grouped into two categories: asexual and sexual.
Sexual reproduction involves the fusion of male and female gametes, whereas in asexual reproduction new plants may develop from vegetative parts of the plant (vegetative reproduction) or may arise from embryos that develop without fertilization (apomixis).
Fertilization is the process of fusion of the female gamete, the ovum or egg and the male gamete produced in the pollen tube by the pollen grain. Fertilization in flowering plants was discovered by Strassburger in 1884.
Flowers are the reproductive structures of angiosperms. They vary greatly physically and are of great diversity in methods of reproduction. The process of fertilization in plants occurs when gametes in haploid conditions meet to create a zygote which is diploid.
The male gametes of the flower are transferred on to the female reproductive organs through pollinators. The final product of this process is the formation of embryo in a seed.
In this lesson you will learn about :
1) What is Fertilization?
2) The Pollen Grain (Male Gamete)
3) The Ovule (Containing Female Gamete)
4) Microsporogenesis and Megasporogenesis
5) Germination of Pollen Grain
6) Double Fertilization
7) Post Fertilization Events
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Plant fertilization is the union of male and female gametes (reproductive cells) to produce a zygote (fertilized egg)
Double Fertilization
Both the male gametes/sperms participate in sexual reproduction.
Two male gametes fuse with one female gamete wherein one male gamete fertilizes the egg to form a zygote, whereas the other fuses with two polar nuclei to form an endosperm
Triple fusion is the fusion of the male gamete with two polar nuclei inside the embryo sac of the angiosperm.
Porogamy - entry through the micropyle.
Chalazogamy - entry through the Chalaza
Mesogamy - entry through the middle part or the integuments
Steps leading to fertilization
Germination of the pollen grain:
Stigma function is to provide place of lodging and germination of the pollen grain after pollination.
Types of stigmas-
Wet stigmas
Secrete exudates like water and other nutrients
In the form of droplets on the stigma.
Exudates made up of a mix of water, lipids, sugars, amino acids, phenolic compounds.
Highly viscous and adhesive. Ex: Petunia, Zea etc.
Dry stigma
Do not secrete exudates Ex: Gossypium
Double Fertilization & Triple Fusion:
Both the male gametes are involved in the fertilization.
Fertilize two different components of the embryo sac - Double Fertilization
One fuses with the egg nucleus (syngamy) -> Zygote(2n)
second fuses with polar nuclei -> primary endosperm nucleus (PEN).
Involves fusion of three nuclei - Triple fusion -> Endosperm(3n)
Pollen tube in the synergids:
Entry only through micropyle. Guided by oburator
Presence of chemotropic substances
Collapse of one the synergids prior to entry of the pollen tube.
Pollen tube in the synergids:
Entry only through micropyle. Guided by oburator
Presence of chemotropic substances
Collapse of one the synergids prior to entry of the pollen tube.
Discharge of pollen tube contents (two male gametes, vegetative nucleus and cytoplasm) into the synergids.
Disorganization of tube nucleus
Polyspermy &Heterofertilization
Heterofertilization - Type of double fertilization in plants in which endosperm and embryo are genetically different.
This happens when two different sperm nuclei from two different pollen tubes happen to enter the same embryo sac.
Dr. T. Annie Sheron
Annie Sheron
Kakatiya Government College
angiosperms
morphology of a flowering plant
parts of flowering plant.
What are angiosperms? Angiosperms are plants that produce flowers and bear their seeds in fruits. They are the largest and most diverse group within the kingdom Plantae, with about 300,000 species. Angiosperms represent approximately 80 percent of all known living green plant.
The outstanding and most significant feature of the flowering plants (and that which sets them out from other vascular plants) is the flower. Understanding the flower structure and names of the parts is important as it is the most important set of characters for both recognizing and keying species, genera, families, etc.
Floral parts (terms & illustrations)
1. Peduncle / pedicel - floral stalk
2. Receptacle - the modified shoot or floral axis
3. Sepals / calyx - the outer most whorl; collectively all sepals are called the calyx. Sepals are typically green and protect the inner floral parts in buds
4. Petals / corolla -the next whorl, collectively all petals are called the corolla. Petals are typically brightly colored and and assist in attracting pollinators. The sepals and petal combined are called the perianth. If the perianth parts cannot be differentiated into sepals and petals, that is, that look so much alike, then they are called tepals.
5. Stamens (androecium) - the next whorls, each stamen has two parts: filament and anthers. Androecium or "male house", the name for all the stamens. The anthers house the microsporangia which undergo meiosis and produce pollen grains.
6. Nectaries - are often associated with flowers, they are found at the receptacle and offer a reward to animal pollinators.
7. Carpels (gynoecium) - The innermost and final whorl is composed of all the carpels and is the site for pollination and fertilization. Collectively all carpels are called the gynoecium: "female house". Carpel has three parts: stigma which receives pollen, the style which is the a slender region specialized for pollen tube growth and the ovary which is an enlarged basal portion and surrounds and protects the ovules. The structure(s) in the center of the flower are often referred to as the pistil(s). Pistil is a layman's term for "flask-shape" structure, so anything with that structure is called a pistil. This is one of the more confusing parts of the flower; more on this below.
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs.
In addition to facilitating the reproduction of flowering plants, flowers have long been admired and used by humans to bring beauty to their environment, and also as objects of romance, ritual, religion, medicine and as a source of food.
In this lesson you will learn about :
1) Flower - Definition & Functions
2) Floral Symmetry
3) Pedicellate & Sessile Flowers
4) Insertion of Floral Leaves on the Thalamus
5) Parts of a Flower
6) Some Important Terms related to Flowers
7) Floral Whorls - Calyx, Corolla, Androecium and Gynoecium
8) Placentation
9) Inflorescenece
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next lesson. Thanks.
Introduction to Sexual Reproduction in Flowering Plants, Flower, Structure of Flower, Male Reproductive Part of Flower (Stamens), Development of Anther walls, Anther Walls, Microsporangium (Pollen Sac)
2. FLORAL STRUCTURE
DEPARTMENT OF GENETICS AND PLANT BREEDING
ALLAHABAD SCHOOL OF AGRICULTURE
SAM HIGGINBOTTOM INSTITUTE OF AGRICULTURE TECHNOLOGYAND SCIENCES
(Formerly Allahabad Agricultural Institute)
DEEMED TO BE UNIVERSITY
Allahabad- India -211007
2012
By
Deva Ram
M.Sc Ag SST
SUBMITTED TO
Dr . SHAILESH MARKER
Head of department,
Dept. of Genetics and plant
breeding ,
SHIATS
3. Topic: floral structure
Contents
Introduction to floral structure
Flower parts and their functions
Classification of flowers
Floral formula and diagram
Floral biology of some families viz, Graminae,
leguminaceae and malvaceae
Summary and conclusion
4. FLOWER
A flower is the
reproductive structure
found in plants.
The biological
function of a flower is
to mediate the union
of male sperm with
female ovum in order
to produce seeds.
5. Flower Structure
FLOWER sits a top of a stem
called peduncle.
Sepals from the latin sepalum
“covering” .
Petals from the latin petalum “to
spread out”.
Stamens are the pollen producing
part of a flower.
Androecium “house of man”.
Carpel from the greek word
carpos “fruit”.
Collectively known as
gynoecium “house of woman”.
6. Flower Part Form and Function
Peduncle Flower stalk.
Receptacle Part of flower stalk bearing the floral organs, at base of flower.
Sepal Leaf-like structures at flower base, protects young flower bud.
Calyx All the sepals together form the calyx.
Petal
Located in and above the sepals, often large and colourful, sometimes
scented, sometimes producing nectar. Often serve to attract pollinators
to the plant.
Corolla All the petals together form the corolla.
Stamen
Male part of the flower, consisting of the anther and filament, makes
pollen grains.
7. Filament The stalk of the stamen which bears the anther.
Anther The pollen bearing portion of a stamen.
Pollen
Grains containing the male gametes. Immature male gametophyte
with a protective outer covering.
CarpelPistil Female part of the flower. Consisting of the stigma, style and ovary.
Stigma
Often sticky top of carpel, serves as a receptive surface for pollen
grains.
Style
The stalk of a carpel, between the stigma and the ovary, through
which the pollen tube grows.
Ovary
Enlarged base of the carpel containing the ovule or ovules. The ovary
matures to become a fruit.
Ovule
Located in the ovaries. Carries female gametes. Ovules become seeds
on fertilization.
9. Types of Flower
Flower can vary in the type of
structure present.
A flower containing all four
modified leaves is said to be
complete.
If a flower that lacks any of these
modified leaves is said to be
incomplete.
Incomplete flower
11. BASED ON SHAPE OF FLOWER
The sex of a flower can be described in three ways:
1.Staminate flowers: Flowers bearing only male sex parts. These
are sometime referred to as "male flowers".
2.CarpellatePistillate Flowers: Flowers bearing only female sex
parts. These are sometimes referred to as "female flowers".
3.HermaphhroditeComplete flowers: Flowers bearing both male
and female sex parts.
14. A flower is basically made
up of four concentric rings
of structures.
There is an outer ring of
modified leaves called sepals.
These provide protection to
the flower before it opens and are usually green. This
outer ring is known as the calyx.
Inside the sepals is another ring of modified leaves
called petals which are often brightly coloured. This
layer is known as the corolla.
Floral Diagram
15. Floral Formulas and Diagrams
A floral formula is a "shorthand"
method used to represent the
structure of a flower using the
standard set of symbols shown at
the right.
The four major floral parts are always shown in the same
order; sepals (CA), petals (CO), stamens (A), and carpels
(G). The number of each part in the flower is indicated with
a superscript number after the letters.
16. Graminae family
Cereal crops are mostly grain crops belonging to the
grass family Graminae (Poaceae).
The word cereal is derived from ceres, the name of
the roman Goddess of harvest and agriculture.
The major cereal crops are Wheat, Rice, Corn,
Barley, Rye, Oat, and include the millets.
Several non grass crops grown for their grain are
called pseudocereals.
Infloroscence of Rice is called Spikelet. Spikelet
consists of one fertile and two vestigial florets
represented by two glumes below the fertile floret.
GENERAL CHARACTERS
17. Characteristics of Rice
The lemma may or may not be indurated,
entire, pointed, hairy or glabrous, strongly
carinate, awnless or mucronate or awnless.
Palea present relatively long, but shorter than lemma
Fertile floret: hermaphrodite, cleistogamous or chasmogamous
in some cases cross pollination is prevelent, calyx and
corolla(perianth) are called lodicules.
Stamens 6, anthers 2-3mm long with filaments, not penicillate,
versatile, ovary glabrous, monocarpellary, usually one ovule,
placentation basel, styles fused(basally) or free to their basaes.
Stigmas bifid, and feathery.
20. Characteristics of Wheat
Inflorescence: spike, the basic unit of the
inflorescence is called a spikelet, typiclly
consisting of a basaal pair of minute sterile
bracts called glumes.
One or more distichously arranged distal florets on an often zig zag
extension of the spikelet axis called the rachilla.
The average spike of common wheat contains 25-30 grains in 14-17
spikelets.
Androecium typically consists of 3 or occasionally 6 distinct stamens,
anthers yellow.
Gynoecium consists of a single compound pistil of 2 or sometimes 3
carpels, an equal number of styles with feathery stigmas, and a
superior ovary with one locule.
23. Characteristics of Maize
The corn plant is normally monoecious.
The staminate flowers is called tassel at
the top of the stalk.
The mature pistilate inflorescence is called cob(silk).
The spikelets are usually arranged in pairs, one sessile and the other
pediceled, the spikelet is completely enclosed by two firm.
There are two florets per spikelet, each floret contains 3 stamens, 2
lodicules and a rudimentary pistil.
The lemma and palea are thinner and shorter than the glumes
The single ovary in a fertile floret bears a long style are silk which is
forked at the tip.
The silk are ordinarily 10-30cm long.
25. GENERAL CHARACTERS OF
LEGUMINACEAE FAMILY
The flowers often have five generally fused sepals
and five free petals.
They are generally hermaphrodite, and have a short
hypanthium, usually cup shaped.
There are normally ten stamens and one elongated
superior ovary, with a curved style. They are usually
arranged in indeterminate inflorescences.
Fabaceae are typically entomophilous plants (i.e. they
are pollinated by insects), and the flowers are usually
showy to attract pollinators.
27. General characteristics of Redgram
Infloroscence: Terminal or axillary raceme.
Flowers: Bisexual irregular, zygomorphic,
pentamerous, yellow, red or yellow-purple with
brownish black in colour.
Calyx: Gamosepalous, four lobed, two lobes being
united.
Corolla: Papilionaceous, standard petal auricled.
Wings and keel yellow of equal length, keel
incurved at apex.
28. Androecium lie within the two keel petals, nine unequal
stamens unite to make up the 10th stamen is free vexillary,
diadelphous(9+1)
The filaments elongate in the bud and pollen is shed the day
before the flower opens.
Gynoecium: monocarpellary, superior many ovules in
marginal placentation. Ovary and base of style hairy; stigma
knob shaped.
30. General characteristics of Groundnut
The flowers are bisexual,
zygomorphic, complete
and sessile.
The ovary is surrounded by the
base of the hypanthium.
Petals are orange, yellow, cream or
rarely white.
Wings are yellow at the base and orrange apically two brick red,
keel coloureless to faintly yellow.
There are 10 stamens, sterile filaments usually 2,
anthers 8.
The tip of the ovary, bearing from 1-5 ovules,grows out from the
between floral bracts.
31. GENERAL CHARACTERISTICS OF
MALVACEAE FAMILY
Usually herbaceous, sometimes trees or shrubs.
Leaves are alternate, stipulate, simple and entire.
The stamens are five to numerous, and
connate at least at their bases, but
often forming a tube around the pistils.
The pistils are composed of two to many
connate carpels.
The ovary is superior, with axial placentation, with
capitate or lobed stigma.
The flowers have nectaries made of many tightly
packed glandular hairs, usually positioned on the sepals.
32. Flower morphology, continued
Androecium-
Stamens numerous, filaments connate
into a tube for most of their length.
Anthers Unilocular.
Gynoecium-
Ovary Superior.
Carpels (1) 2-many, either loosely
coherent in a ring around the base
of the single style or wholly united in a compound ovary.
Style with as many long or short branches as there are
carpels.
Ovules 1-many per carpel.
35. Summary and conclusion
Summary: By studying the flower structure of the field
crops we came to know about its floral biology, floral
morphology and pollination mechanism to take up the
hybridization.
Conclusion: As a part of Seed Technologist or plant
breeder it is necessary to know about the floral biology,
morphology and pollination mechanism to maintain the
genetic purity, isolation distance and germplasm etc.