BOI 101/3 (Fruits)

Organisms Biodiversity

Prof Madya Dr Rahmad Zakaria

rahmadz@usm.my
Adapted From:
Dr. Rosazlina Rusly
rosazlinarusly@usm.my
• Cynometra cauliflora (Fabaceae)
• Annona reticulata (Anonaceae)
• Theobroma cacao (Malvaceae)
• Phyllanthus acidus (Phyllanthaceae)
• Garcinia atroviridis (Clusiaceae)
BOI101RR

Resulted from
flower
Fertilization
 The process:
1. Once pollen grains have been transferred from anther to stigma, the tube
cell, one of the two cells in the pollen grain, grows a thin pollen tube down
through the style and into an ovule in the ovary.
2. How does the pollen tube “know” where to grow? Botanists have found that
molecular signals from the ovule guide the growing pollen tube toward the
ovule.
3. Once a pollen tube penetrates the ovule, the attracting signals cease. As a
result, only one pollen tube enters each ovule.
4. The second cell (the generative cell) within the pollen grain divides to form
two male gametes (the sperm cells), which move down the pollen tube and
enter the ovule.
5. After fertilization has occurred, the ovule develops into a seed, and the ovary
surrounding it develops into a fruit.
Fruits are mature and ripened ovaries of the BOI101RR

flower
 Fruits are mature,
ripened ovaries
• Fruits provide protection for the
enclosed seeds and sometimes aid
in their dispersal.
• There are several types of fruits;
their differences result from
variations in the structure or
arrangement of the flowers from
which they were formed.
• The four basic types of fruits are
simple fruits, aggregate fruits and
multiple fruits.
• Most fruits are simple fruits. A
simple fruit develops from a single
carpel or several fused carpels. At
maturity, simple fruits may be fleshy
or dry.
• Two examples of simple, fleshy
fruits are berries and drupes.
 • A drupe is a simple, fleshy or fibrous fruit that contains a hard stone surrounding a single
seed. Examples of drupes include peaches, cherries, avocados, olives, and coconuts.
Simple: • A berry is a fleshy fruit that has soft tissues throughout and contains few to many seeds; a
tomato is a berry, as are grapes, blueberries, cranberries, and bananas.
Fleshy • Pome is similar to a berry except that the endocarp is papery or leathery (apple +pears).
• A hesperidium (pl., hesperidia), which has a leathery fruit wall with numerous oil glands
Fruits surrounding the succulent cavities where the seeds occur. Citrus fruits (lemons, limes,
oranges, and grapefruits) are hesperidia.
• A pepo is a modified berry in which the fruit wall is a leathery rind. Pumpkin, cucumber,
and watermelon fruits are pepos.
 Pericarp
• In fleshy fruits, the pericarp
is typically made up of
three distinct layers.
• The exocarp (also known
as epicarp), which is the
outermost layer.
• The mesocarp, which is the
middle layer.
• The endocarp, which is the
inner layer surrounding the
ovary or the seeds.
• In a citrus fruit, the exocarp
and mesocarp make up
the peel.
• In dry fruits, the layers of
the pericarp are not clearly
distinguishable.
 A. Simple: Dry
fruits
• Dry fruit can be either dehiscent,
where they pop open and release
their seeds; or indehiscent, where
they do not pop open.
• The dehiscent fruits are distinguished
from one another by the way they
split.
• A milkweed pod is an example of a
follicle, a simple, dry fruit that splits
open along one suture to release its
seeds.
• A legume is a simple, dry fruit that
splits open along two sutures (the
top and bottom). Beans, peas,petai,
soybeans.
• A capsule is a simple, dry fruit that
splits open along multiple sutures or
pores in many ways. Iris, poppy,
buckeye, and cotton fruits are
capsules.
 The
dehiscent
fruits

where they pop open and release

their seeds
 Simple: Dry fruits
• The indehiscent fruits which does not split open
at maturity. It is subdivided into:-
• An achene is simple and dry, does not split open
at maturity, and contains a single seed.
However, the seed coat of an achene is not
fused to the fruit wall. Instead, the single seed
is attached to the fruit wall at one point only,
permitting an achene to be separated from its
seed. The sunflower fruit is an example of an
achene. One peels off the fruit wall (the shell)
to obtain the sunflower seed within.
• Samara: A dry indehiscent, one seeded fruit in
which the pericarp develops into thin winged
structure around the fruit.
Example: Acer, maple, Most Dipterocarp.
• Caryopsis or grains. Each caryopsis contains a
single seed. Because the seed coat is fused to
the fruit wall, a caryopsis looks like a seed
rather than a fruit. Example: Kernels of corn,
Paddy.
• Nuts are simple, dry fruits that have a stony
wall and do not split open at maturity. Nuts are
usually large and one-seeded. Examples of nuts
include chestnuts, acorns, and hazelnuts.
 The
indehiscent
fruits

Samara (simple fruit)

where they do not pop open A dry indehiscent,
one seeded fruit in
which the pericarp
develops into thin
winged structure around
the fruit.

Shorea sp
 • Aggregate fruits are a second main type of fruit.
B: Aggregate • An aggregate fruit is formed from a single flower that contains several separate
Fruits (free) carpels. After fertilization, each ovary from each individual carpel enlarges.
• As they enlarge, the ovaries may fuse to form a single fruit. Raspberries,
blackberries, and magnolia fruits are examples of aggregate fruits.
 C: Multiple fruits

• A third type of fruit is the multiple

fruit, which forms from the carpels
of many flowers that grow close to
one another on a common floral
stalk (in a single inflorescence).
• The carpel from each flower fuses
with nearby carpels as it develops
and enlarges after fertilization.
• Pineapples, figs, and mulberries are
multiple fruits.

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Musa ingens - The World's Largest Banana Tree, Papua
New Guniea.

• The banana tree can grow

up to 15 meters high.
• Bunch of bananas can
weigh up to 60 kilograms
apiece with a length of 18
cm and a diameter of 3-4
cm.

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Tembikai/Citrullus lanatus (Cucurbitaceae)
Labu/Cucurbita pepo (Cucurbitaceae)
Discuss the
importance of
fruits
 Conclusions:
• Fruits are important plant organ
(Angiosperms) for seed protection and
dispersion
• Closely related to flower
• Variable size, shapes and structure
• Are modified according to methods of
dispersion
• Have high economy and etno-botany
values
• Influences the plant species diversity

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