http://en.wikipedia.org/wiki/File:Nectarine_Fruit_Development.jpg

From Flowers to Fruits Module 4 Unit 13 Lesson 3

How did that happen? Let’s find out! 1

Introduction

Young buds can be observed which must have grown into new flowering shoots.

Some flowers are fully developed and more than likely some were already pollinated. Successful pollination and also fertilization has obviously occurred as ripened fruit are present observed.

The plant has taken another journey from flowers to fruits!

2

Objectives

When you finish this section, you should be able to:

1. describe the structure of a ‘typical’ simple fruit.

2. relate the structure of selected fruits to the structure of the flowers from which they were formed.

3

Fruit or Vegetable?

4

When you eat each of these vegetables, what part of a plant are you really eating?

http://urbanext.illinois.edu/gpe/case1/c1facts2e.html

www.tntisland.com/fruits.html

CHECKCHECK

FEEDBACK

Did you know that they are ALL ‘ripened’ ovaries and are really the products of fertilization? They are fruits.

So, when you eat those vegetables shown, you’re

really eating what was once the ovary!

http://en.wikipedia.org/wiki/Fruit 5

How is a fruit formed?

Remind yourself of what happens during fertilization by clicking open this link>> http://www.emunix.emich.edu/~ghannan/systbot/doublefertanimation.html

Stamen

Stigma

Ovary

Pea flowerOvule

Seed

Pea fruit

Simple fruit

6

As a fruit forms…

…. sepals, petals, stamens wither and usually fall off. (Sometimes sepals may remain attached to the fruit.) Look at the sepals

that remain on the

Rose hips.

7

As a fruit forms…. …. its weight might cause it to hang in an upside

down position in relation to the flower from which it formed.

Its wall can

dry out.

http://en.wikipedia.org/wiki/File:Fruit_I_IMG_8692.jpg

http://toptropicals.com/pics/garden/c21/0665.jpg 8

Barbados Pride

Poinciana fruits

What is a fruit?

A fruit is the packaging for seeds!

• It is an ovary in which further development of the fertilized ovule/s has taken place, resulting

in seed formation.

• A fruit has a fruit wall or pericarp,

a placenta to which each seed is attached by a stem called the funicle.

9

What is a Fruit?

• Each fruit has two scars – one where the style was attached to the ovary, the other on the opposite side, where it was attached by the pedicel to the plant.

• The two functions of a fruit are:1. to protect the seed/s and

2. to aid in seed dispersal.

A fruit is a guarantee of the next generation because it contains the seed with an embryo plant in it.

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exocarp or skinThe seed is protected inside the hard endocarp

The Parts of a fruit and its seed

http://waynesword.palomar.edu/termfr4.htm

scar of pedicel

scar of the style

11

The Parts of a fruit and its seed

The pericarp is different from the seed coat or testa.

http://en.wikipedia.org/wiki/File:Drupe_fruit_diagram-en.svg

12

http://en.wikipedia.org/wiki/File:Illustration_Punica_granatum2.jpg

Pomegranate – Look at this diagram (Top left)

and photo (Top Right) of a flower.

Ovary withovules

Stamens

Pistil

Here are photos of the whole fruit and one cut open (Right).

Sepal

http://waynesword.palomar.edu/ecoph20.htm13

Activity

Label three parts of the fruit and explain from which part of a Pomegranate flower each part grew.

CHECKCHECK 14

FEEDBACK Click open this website, scroll down to see photos

of pomegrante fruit: http://waynesword.palomar.edu/termfr4.htm

.

fruit wall comprising

leathery exocarp, mesocarp = ovary

wall and receptacle

scar = remains of pedicel

seeds = fertilized ovules

persistent sepals (with stamen cluster inside)

Pomegranate fruit formed from an inferior ovary

15

Why aren’t all fruits exactly alike?

Well…. that depends on the flowers from which they form, and how they formed after fertilization!

Depending on the structure of the flower, fruits develop with different structures which enables us to put them into one of several groups.

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How fruits develop: 1. Simple Fruit

1. Simple fruit - develop from one carpel from a single, separate flower and can be:

• Dry (Visit: http://www.backyardnature.net/frt_simp.htm )

• Fleshy (Visit: http://www.backyardnature.net/frt_flsh.htm )

• Accessory

e.g. peas/ other pods,

tomatoes, oranges,

capsules, grains, plums,

mangoes. Click open and read from the above websites.

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http://www.backyardnature.net/frt_3grp.htm

Simple fruits

The fruit wall may dry out as the fruit develops from the ovary.

L – R: Peanut, Tamarind are Simple Fruits

18http://waynesword.palomar.edu/termfr1.htm#baobab

Simple fruit- Sunflower

• Forms small, one-seeded simple fruits with dried-out pericarps.

• The three pericarp layers are not distinguishable.

19

http://jbworld.jbs.st-louis.mo.us/science/resources/flower/fruit3.html

Simple fruit - Orange

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http://visual.merriam-webster.com/plants-gardening/plants/fruits/fleshy-fruit-citrus-fruit.php

The middle layer of the pericarp often becomes fleshy with stored food. The outer layer often changes colour when ripe.

Simple fruit - CucumberFemale flower will develop into the fruit after fertilization.

Prickly inferior ovary, which is the future cucumber

http://www.backyardnature.net/fl_def.htm

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How fruits develop: 2. Compound Fruit

2. Compound fruit - develops from several ovaries in either a single or multiple flower/s. Includes:

• Aggregate fruits - has many small fruits each with a seed; develops from different ovaries of a single flower e.g. Strawberry

• Multiple fruits – with fruits of separate flowers merged or packed closely together e.g. Pineapple, Jackfruit, Breadfruit.

22

As a fruit forms…

The single flower has

several pistils that

mature together and

stick/aggregate together

as a clustered unit on a

single receptacle, forming

an Aggregate fruit.

It has seeds from different ovaries of the single flowers.

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flowerhttp://www.backyardnature.net/frt_3grp.htm

Aggregate fruit

Stamen

Stigma

Ovary

Raspberry flower

Stamen

Carpels

Carpel(fruitlet)

Raspberry fruit

Aggregate fruit

Raspberry

http://visual.merriam-webster.com/plants-gardening/plants/fruits/fleshy-fruit-berry-fruit_2.php

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How fruits develop

Soursop is a large, fleshy, berrylike Aggregate fruit. It is formed by the aggregation of ripened ovaries + the fleshy receptacle.

Click open this link. Read to see how Soursop and paw-paw fruits relate to the flowers from which they were formed:http://www.biology-resources.com/plants-fruit-tropical.html

25http://www.fotosearch.com/photos-images/pawpaw.html

Activity

On the next slides, look at the Soursop and Strawberry diagrams, then examine actual samples.Check for paw=paw at http://www.biology-resources.com/documents/plant-fruit-tropical-2.doc

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Accessory fruit forms…

…. some or all of the fleshy, usually edible, part might not be formed from the ovary, but instead is derived from the receptacle that holds the ovaries or from some other adjacent tissue e.g. receptacle, producing an Accessory fruit. Click open, scroll down and read about the (American) Apple and Strawberry at these websites. •http://www.biology-resources.com/documents/plant-fruit-3.doc

•http://waynesword.palomar.edu/termfr4.htm

Cut open and examine samples of the fruits.

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Skin

Receptacle Ovary /real fruit

wall

American Apple – an Accessory fruit

28

Strawberry Flower

http://en.wikipedia.org/wiki/File:Longitudinal_section_of_raspberry_flower.gif

http://www.countrysideinfo.co.uk/flower.htm

Gynoecium = many free simple carpels

29

Close-up of the surfaceof a young strawberry shows simple fruits each with style and stigma.

http://en.wikipedia.org/wiki/Strawberry

The receptacle and flower stalk form part of the Strawberry fruit wall.

30

This accessory “fruit"

is actually an enlarged

receptacle.

http://waynesword.palomar.edu/termfr4.htm

http://visual.merriam-webster.com/plants-gardening/plants/fruits/fleshy-fruit-berry-fruit_3.php

“seed” is really a simple fruit

Strawberry = Aggregate-accessory fruit

31

As a fruit forms…

…a Multiple Fruit may develop. Each fruit forms when a cluster of separate flowers (each with its own pistil) that are grouped together on the same inflorescence have their fertilized ovules mature together to form one fruit.

32

Pineapple flowers (Diagram, left; photo, right)

Pineapple inflorescence

Multiple fruit

Flower

Eachsegmentdevelopsfrom the carpelof oneflower

Pineapple fruit

http://upload.wikimedia.org/wikipedia/commons/c/cb/Pineapple_and_cross_section.jpg

Click open http://jbworld.jbs.st-louis.mo.us/science/resources/flower/fruit5.html and read the information presented.

Young pineapple inflorescence. Each unit is a flower.

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Pineapple = Multiple fruit

Pineapple inflorescence

Multiple fruit

Flower

Eachsegmentdevelopsfrom the carpelof oneflower

Pineapple fruit

http://www.botany.hawaii.edu/faculty/webb/BOT201/Angiosperm/FlowerFruit.htm

Central axis is the receptacle

34

Jackfruit - is a Multiple fruit; it is formed from the fusion of ovaries from many individual flowers plus the fleshy stem axis.

single carpel of a single flower

seeds and pericarp

35

Breadfruit- a Compound False Fruit

• Male and female flowers grow on thesame breadfruit tree.(Only female flowers form fruits.)

• The hexagon-like disks visible on theskin are flowers that became fruits.

www.nairaland.com/nigeria/topic-359719.0.html

http://en.wikipedia.org/wiki/Breadfruit

36

Breadfruit - this compound, false fruit develops from the swollen perianth of over 1,500 female flowers growing on a fleshy receptacle.

http://en.wikipedia.org/wiki/Breadfruit 37

Cashew Apple – a false fruit The fleshy Cashew ‘apple’ is the swollen

succulent stalk/pedicel and base. The ‘nut’ is a dry fruit with one seed. Both parts store food.

www.fao.org/.../vlibrary/ac306e/ac306e04.htm slog.thestranger.com/2008/04/new_fruit 38

Summary

Fruits differ from each other because…

1. the flower structures were different especially the pistil structure and the number and position of fertilized ovules that became the seeds.

2. the position of the ovary in respect to other floral whorls and also the sepals, petals stamens may/may not be retained as the fruit forms.

39

Summary

Fruits differ from each other because…

3. parts such as the receptacle or flower stalk may become incorporated in the fruit wall.

4. the ovary (fruit) wall changes in different ways e.g. becoming dry/fleshy, coloured, hairy etc.

The next slide gives a summary diagram of thecycle of development from formation of the zygoteto fruit.

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Summaryhttp://leavingbio.net/The%20Structure%20Functions%20of%20Flowers_files/image031.jpg

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